Merge branch 'master' of https://github.com/ClickHouse/ClickHouse into nanodbc

base/CMakeLists.txt

@@ -8,6 +8,7 @@ add_subdirectory (loggers)
 add_subdirectory (pcg-random)
 add_subdirectory (widechar_width)
 add_subdirectory (readpassphrase)
+add_subdirectory (bridge)
 
 if (USE_MYSQL)
     add_subdirectory (mysqlxx)

base/bridge/CMakeLists.txt

@@ -0,0 +1,7 @@
+add_library (bridge
+    IBridge.cpp
+)
+
+target_include_directories (daemon PUBLIC ..)
+target_link_libraries (bridge PRIVATE daemon dbms Poco::Data Poco::Data::ODBC)
+

base/bridge/IBridge.cpp

@@ -0,0 +1,238 @@
+#include "IBridge.h"
+
+#include <IO/ReadHelpers.h>
+#include <boost/program_options.hpp>
+#include <Poco/Net/NetException.h>
+#include <Poco/Util/HelpFormatter.h>
+#include <Common/StringUtils/StringUtils.h>
+#include <Formats/registerFormats.h>
+#include <common/logger_useful.h>
+#include <Common/SensitiveDataMasker.h>
+#include <Server/HTTP/HTTPServer.h>
+
+#if USE_ODBC
+#    include <Poco/Data/ODBC/Connector.h>
+#endif
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+    extern const int ARGUMENT_OUT_OF_BOUND;
+}
+
+namespace
+{
+    Poco::Net::SocketAddress makeSocketAddress(const std::string & host, UInt16 port, Poco::Logger * log)
+    {
+        Poco::Net::SocketAddress socket_address;
+        try
+        {
+            socket_address = Poco::Net::SocketAddress(host, port);
+        }
+        catch (const Poco::Net::DNSException & e)
+        {
+            const auto code = e.code();
+            if (code == EAI_FAMILY
+#if defined(EAI_ADDRFAMILY)
+                || code == EAI_ADDRFAMILY
+#endif
+            )
+            {
+                LOG_ERROR(log, "Cannot resolve listen_host ({}), error {}: {}. If it is an IPv6 address and your host has disabled IPv6, then consider to specify IPv4 address to listen in <listen_host> element of configuration file. Example: <listen_host>0.0.0.0</listen_host>", host, e.code(), e.message());
+            }
+
+            throw;
+        }
+        return socket_address;
+    }
+
+    Poco::Net::SocketAddress socketBindListen(Poco::Net::ServerSocket & socket, const std::string & host, UInt16 port, Poco::Logger * log)
+    {
+        auto address = makeSocketAddress(host, port, log);
+#if POCO_VERSION < 0x01080000
+        socket.bind(address, /* reuseAddress = */ true);
+#else
+        socket.bind(address, /* reuseAddress = */ true, /* reusePort = */ false);
+#endif
+
+        socket.listen(/* backlog = */ 64);
+
+        return address;
+    }
+}
+
+
+void IBridge::handleHelp(const std::string &, const std::string &)
+{
+    Poco::Util::HelpFormatter help_formatter(options());
+    help_formatter.setCommand(commandName());
+    help_formatter.setHeader("HTTP-proxy for odbc requests");
+    help_formatter.setUsage("--http-port <port>");
+    help_formatter.format(std::cerr);
+
+    stopOptionsProcessing();
+}
+
+
+void IBridge::defineOptions(Poco::Util::OptionSet & options)
+{
+    options.addOption(
+        Poco::Util::Option("http-port", "", "port to listen").argument("http-port", true) .binding("http-port"));
+
+    options.addOption(
+        Poco::Util::Option("listen-host", "", "hostname or address to listen, default 127.0.0.1").argument("listen-host").binding("listen-host"));
+
+    options.addOption(
+        Poco::Util::Option("http-timeout", "", "http timeout for socket, default 1800").argument("http-timeout").binding("http-timeout"));
+
+    options.addOption(
+        Poco::Util::Option("max-server-connections", "", "max connections to server, default 1024").argument("max-server-connections").binding("max-server-connections"));
+
+    options.addOption(
+        Poco::Util::Option("keep-alive-timeout", "", "keepalive timeout, default 10").argument("keep-alive-timeout").binding("keep-alive-timeout"));
+
+    options.addOption(
+        Poco::Util::Option("log-level", "", "sets log level, default info") .argument("log-level").binding("logger.level"));
+
+    options.addOption(
+        Poco::Util::Option("log-path", "", "log path for all logs, default console").argument("log-path").binding("logger.log"));
+
+    options.addOption(
+        Poco::Util::Option("err-log-path", "", "err log path for all logs, default no").argument("err-log-path").binding("logger.errorlog"));
+
+    options.addOption(
+        Poco::Util::Option("stdout-path", "", "stdout log path, default console").argument("stdout-path").binding("logger.stdout"));
+
+    options.addOption(
+        Poco::Util::Option("stderr-path", "", "stderr log path, default console").argument("stderr-path").binding("logger.stderr"));
+
+    using Me = std::decay_t<decltype(*this)>;
+
+    options.addOption(
+        Poco::Util::Option("help", "", "produce this help message").binding("help").callback(Poco::Util::OptionCallback<Me>(this, &Me::handleHelp)));
+
+    ServerApplication::defineOptions(options); // NOLINT Don't need complex BaseDaemon's .xml config
+}
+
+
+void IBridge::initialize(Application & self)
+{
+    BaseDaemon::closeFDs();
+    is_help = config().has("help");
+
+    if (is_help)
+        return;
+
+    config().setString("logger", bridgeName());
+
+    /// Redirect stdout, stderr to specified files.
+    /// Some libraries and sanitizers write to stderr in case of errors.
+    const auto stdout_path = config().getString("logger.stdout", "");
+    if (!stdout_path.empty())
+    {
+        if (!freopen(stdout_path.c_str(), "a+", stdout))
+            throw Poco::OpenFileException("Cannot attach stdout to " + stdout_path);
+
+        /// Disable buffering for stdout.
+        setbuf(stdout, nullptr);
+    }
+    const auto stderr_path = config().getString("logger.stderr", "");
+    if (!stderr_path.empty())
+    {
+        if (!freopen(stderr_path.c_str(), "a+", stderr))
+            throw Poco::OpenFileException("Cannot attach stderr to " + stderr_path);
+
+        /// Disable buffering for stderr.
+        setbuf(stderr, nullptr);
+    }
+
+    buildLoggers(config(), logger(), self.commandName());
+
+    BaseDaemon::logRevision();
+
+    log = &logger();
+    hostname = config().getString("listen-host", "127.0.0.1");
+    port = config().getUInt("http-port");
+    if (port > 0xFFFF)
+        throw Exception("Out of range 'http-port': " + std::to_string(port), ErrorCodes::ARGUMENT_OUT_OF_BOUND);
+
+    http_timeout = config().getUInt("http-timeout", DEFAULT_HTTP_READ_BUFFER_TIMEOUT);
+    max_server_connections = config().getUInt("max-server-connections", 1024);
+    keep_alive_timeout = config().getUInt("keep-alive-timeout", 10);
+
+    initializeTerminationAndSignalProcessing();
+
+#if USE_ODBC
+    if (bridgeName() == "ODBCBridge")
+        Poco::Data::ODBC::Connector::registerConnector();
+#endif
+
+    ServerApplication::initialize(self); // NOLINT
+}
+
+
+void IBridge::uninitialize()
+{
+    BaseDaemon::uninitialize();
+}
+
+
+int IBridge::main(const std::vector<std::string> & /*args*/)
+{
+    if (is_help)
+        return Application::EXIT_OK;
+
+    registerFormats();
+    LOG_INFO(log, "Starting up {} on host: {}, port: {}", bridgeName(), hostname, port);
+
+    Poco::Net::ServerSocket socket;
+    auto address = socketBindListen(socket, hostname, port, log);
+    socket.setReceiveTimeout(http_timeout);
+    socket.setSendTimeout(http_timeout);
+
+    Poco::ThreadPool server_pool(3, max_server_connections);
+
+    Poco::Net::HTTPServerParams::Ptr http_params = new Poco::Net::HTTPServerParams;
+    http_params->setTimeout(http_timeout);
+    http_params->setKeepAliveTimeout(keep_alive_timeout);
+
+    auto shared_context = Context::createShared();
+    Context context(Context::createGlobal(shared_context.get()));
+    context.makeGlobalContext();
+
+    if (config().has("query_masking_rules"))
+        SensitiveDataMasker::setInstance(std::make_unique<SensitiveDataMasker>(config(), "query_masking_rules"));
+
+    auto server = HTTPServer(
+        context,
+        getHandlerFactoryPtr(context),
+        server_pool,
+        socket,
+        http_params);
+
+    SCOPE_EXIT({
+        LOG_DEBUG(log, "Received termination signal.");
+        LOG_DEBUG(log, "Waiting for current connections to close.");
+
+        server.stop();
+
+        for (size_t count : ext::range(1, 6))
+        {
+            if (server.currentConnections() == 0)
+                break;
+            LOG_DEBUG(log, "Waiting for {} connections, try {}", server.currentConnections(), count);
+            std::this_thread::sleep_for(std::chrono::milliseconds(1000));
+        }
+    });
+
+    server.start();
+    LOG_INFO(log, "Listening http://{}", address.toString());
+
+    waitForTerminationRequest();
+    return Application::EXIT_OK;
+}
+
+}

base/bridge/IBridge.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <Interpreters/Context.h>
+#include <Server/HTTP/HTTPRequestHandlerFactory.h>
+#include <Poco/Util/ServerApplication.h>
+#include <Poco/Logger.h>
+#include <daemon/BaseDaemon.h>
+
+
+namespace DB
+{
+
+/// Class represents base for clickhouse-odbc-bridge and clickhouse-library-bridge servers.
+/// Listens to incoming HTTP POST and GET requests on specified port and host.
+/// Has two handlers '/' for all incoming POST requests and /ping for GET request about service status.
+class IBridge : public BaseDaemon
+{
+
+public:
+    /// Define command line arguments
+    void defineOptions(Poco::Util::OptionSet & options) override;
+
+protected:
+    using HandlerFactoryPtr = std::shared_ptr<HTTPRequestHandlerFactory>;
+
+    void initialize(Application & self) override;
+
+    void uninitialize() override;
+
+    int main(const std::vector<std::string> & args) override;
+
+    virtual const std::string bridgeName() const = 0;
+
+    virtual HandlerFactoryPtr getHandlerFactoryPtr(Context & context) const = 0;
+
+    size_t keep_alive_timeout;
+
+private:
+    void handleHelp(const std::string &, const std::string &);
+
+    bool is_help;
+    std::string hostname;
+    size_t port;
+    std::string log_level;
+    size_t max_server_connections;
+    size_t http_timeout;
+
+    Poco::Logger * log;
+};
+}

base/mysqlxx/PoolWithFailover.cpp

@@ -2,7 +2,6 @@
 #include <ctime>
 #include <random>
 #include <thread>
-
 #include <mysqlxx/PoolWithFailover.h>
 
 
@@ -15,9 +14,12 @@ static bool startsWith(const std::string & s, const char * prefix)
 
 using namespace mysqlxx;
 
-PoolWithFailover::PoolWithFailover(const Poco::Util::AbstractConfiguration & config_,
-                                   const std::string & config_name_, const unsigned default_connections_,
-                                   const unsigned max_connections_, const size_t max_tries_)
+PoolWithFailover::PoolWithFailover(
+        const Poco::Util::AbstractConfiguration & config_,
+        const std::string & config_name_,
+        const unsigned default_connections_,
+        const unsigned max_connections_,
+        const size_t max_tries_)
     : max_tries(max_tries_)
 {
     shareable = config_.getBool(config_name_ + ".share_connection", false);
@@ -59,16 +61,38 @@ PoolWithFailover::PoolWithFailover(const Poco::Util::AbstractConfiguration & con
     }
 }
 
-PoolWithFailover::PoolWithFailover(const std::string & config_name_, const unsigned default_connections_,
-    const unsigned max_connections_, const size_t max_tries_)
-    : PoolWithFailover{
-        Poco::Util::Application::instance().config(), config_name_,
-        default_connections_, max_connections_, max_tries_}
+
+PoolWithFailover::PoolWithFailover(
+        const std::string & config_name_,
+        const unsigned default_connections_,
+        const unsigned max_connections_,
+        const size_t max_tries_)
+    : PoolWithFailover{Poco::Util::Application::instance().config(),
+            config_name_, default_connections_, max_connections_, max_tries_}
 {
 }
 
+
+PoolWithFailover::PoolWithFailover(
+        const std::string & database,
+        const RemoteDescription & addresses,
+        const std::string & user,
+        const std::string & password,
+        size_t max_tries_)
+    : max_tries(max_tries_)
+    , shareable(false)
+{
+    /// Replicas have the same priority, but traversed replicas are moved to the end of the queue.
+    for (const auto & [host, port] : addresses)
+    {
+        replicas_by_priority[0].emplace_back(std::make_shared<Pool>(database, host, user, password, port));
+    }
+}
+
+
 PoolWithFailover::PoolWithFailover(const PoolWithFailover & other)
-    : max_tries{other.max_tries}, shareable{other.shareable}
+    : max_tries{other.max_tries}
+    , shareable{other.shareable}
 {
     if (shareable)
     {

base/mysqlxx/PoolWithFailover.h

@@ -11,6 +11,8 @@
 namespace mysqlxx
 {
     /** MySQL connection pool with support of failover.
+      *
+      * For dictionary source:
       * Have information about replicas and their priorities.
       * Tries to connect to replica in an order of priority. When equal priority, choose replica with maximum time without connections.
       *
@@ -68,42 +70,58 @@ namespace mysqlxx
         using PoolPtr = std::shared_ptr<Pool>;
         using Replicas = std::vector<PoolPtr>;
 
-        /// [priority][index] -> replica.
+        /// [priority][index] -> replica. Highest priority is 0.
         using ReplicasByPriority = std::map<int, Replicas>;
-
         ReplicasByPriority replicas_by_priority;
 
         /// Number of connection tries.
         size_t max_tries;
         /// Mutex for set of replicas.
         std::mutex mutex;
-
         /// Can the Pool be shared
         bool shareable;
 
     public:
         using Entry = Pool::Entry;
+        using RemoteDescription = std::vector<std::pair<std::string, uint16_t>>;
 
         /**
-         * config_name           Name of parameter in configuration file.
+         * * Mysql dictionary sourse related params:
+         * config_name           Name of parameter in configuration file for dictionary source.
+         *
+         * * Mysql storage related parameters:
+         * replicas_description
+         *
+         * * Mutual parameters:
          * default_connections   Number of connection in pool to each replica at start.
          * max_connections       Maximum number of connections in pool to each replica.
          * max_tries_            Max number of connection tries.
          */
-        PoolWithFailover(const std::string & config_name_,
+        PoolWithFailover(
+            const std::string & config_name_,
             unsigned default_connections_ = MYSQLXX_POOL_WITH_FAILOVER_DEFAULT_START_CONNECTIONS,
             unsigned max_connections_ = MYSQLXX_POOL_WITH_FAILOVER_DEFAULT_MAX_CONNECTIONS,
             size_t max_tries_ = MYSQLXX_POOL_WITH_FAILOVER_DEFAULT_MAX_TRIES);
 
-        PoolWithFailover(const Poco::Util::AbstractConfiguration & config_,
+        PoolWithFailover(
+            const Poco::Util::AbstractConfiguration & config_,
             const std::string & config_name_,
             unsigned default_connections_ = MYSQLXX_POOL_WITH_FAILOVER_DEFAULT_START_CONNECTIONS,
             unsigned max_connections_ = MYSQLXX_POOL_WITH_FAILOVER_DEFAULT_MAX_CONNECTIONS,
             size_t max_tries_ = MYSQLXX_POOL_WITH_FAILOVER_DEFAULT_MAX_TRIES);
 
+        PoolWithFailover(
+            const std::string & database,
+            const RemoteDescription & addresses,
+            const std::string & user,
+            const std::string & password,
+            size_t max_tries_ = MYSQLXX_POOL_WITH_FAILOVER_DEFAULT_MAX_TRIES);
+
         PoolWithFailover(const PoolWithFailover & other);
 
         /** Allocates a connection to use. */
         Entry get();
     };
+
+    using PoolWithFailoverPtr = std::shared_ptr<PoolWithFailover>;
 }

contrib/CMakeLists.txt

@@ -47,7 +47,10 @@ add_subdirectory (lz4-cmake)
 add_subdirectory (murmurhash)
 add_subdirectory (replxx-cmake)
 add_subdirectory (unixodbc-cmake)
-add_subdirectory (xz)
+
+if (USE_INTERNAL_XZ_LIBRARY)
+    add_subdirectory (xz)
+endif()
 
 add_subdirectory (poco-cmake)
 add_subdirectory (croaring-cmake)

debian/clickhouse-common-static.install

@@ -1,5 +1,6 @@
 usr/bin/clickhouse
 usr/bin/clickhouse-odbc-bridge
+usr/bin/clickhouse-library-bridge
 usr/bin/clickhouse-extract-from-config
 usr/share/bash-completion/completions
 etc/security/limits.d/clickhouse.conf

docker/test/integration/base/Dockerfile

@@ -19,7 +19,8 @@ RUN apt-get update \
         tar \
         krb5-user \
         iproute2 \
-        lsof
+        lsof \
+        g++
 RUN rm -rf \
         /var/lib/apt/lists/* \
         /var/cache/debconf \

docker/test/integration/runner/Dockerfile

@@ -31,6 +31,7 @@ RUN apt-get update \
     software-properties-common \
     libkrb5-dev \
     krb5-user \
+    g++ \
     && rm -rf \
         /var/lib/apt/lists/* \
         /var/cache/debconf \

docker/test/integration/runner/compose/docker_compose_mysql_cluster.yml

@@ -0,0 +1,23 @@
+version: '2.3'
+services:
+    mysql2:
+        image: mysql:5.7
+        restart: always
+        environment:
+            MYSQL_ROOT_PASSWORD: clickhouse
+        ports:
+            - 3348:3306
+    mysql3:
+        image: mysql:5.7
+        restart: always
+        environment:
+            MYSQL_ROOT_PASSWORD: clickhouse
+        ports:
+            - 3388:3306
+    mysql4:
+        image: mysql:5.7
+        restart: always
+        environment:
+            MYSQL_ROOT_PASSWORD: clickhouse
+        ports:
+            - 3368:3306

docker/test/integration/runner/compose/docker_compose_postgres.yml

@@ -11,10 +11,3 @@ services:
             default:
                 aliases:
                     - postgre-sql.local
-    postgres2:
-        image: postgres
-        restart: always
-        environment:
-            POSTGRES_PASSWORD: mysecretpassword
-        ports:
-            - 5441:5432

docker/test/integration/runner/compose/docker_compose_postgres_cluster.yml

@@ -0,0 +1,23 @@
+version: '2.3'
+services:
+    postgres2:
+        image: postgres
+        restart: always
+        environment:
+            POSTGRES_PASSWORD: mysecretpassword
+        ports:
+            - 5421:5432
+    postgres3:
+        image: postgres
+        restart: always
+        environment:
+            POSTGRES_PASSWORD: mysecretpassword
+        ports:
+            - 5441:5432
+    postgres4:
+        image: postgres
+        restart: always
+        environment:
+            POSTGRES_PASSWORD: mysecretpassword
+        ports:
+            - 5461:5432

docker/test/integration/runner/dockerd-entrypoint.sh

@@ -21,6 +21,7 @@ export CLICKHOUSE_TESTS_SERVER_BIN_PATH=/clickhouse
 export CLICKHOUSE_TESTS_CLIENT_BIN_PATH=/clickhouse
 export CLICKHOUSE_TESTS_BASE_CONFIG_DIR=/clickhouse-config
 export CLICKHOUSE_ODBC_BRIDGE_BINARY_PATH=/clickhouse-odbc-bridge
+export CLICKHOUSE_LIBRARY_BRIDGE_BINARY_PATH=/clickhouse-library-bridge
 
 export DOCKER_MYSQL_GOLANG_CLIENT_TAG=${DOCKER_MYSQL_GOLANG_CLIENT_TAG:=latest}
 export DOCKER_MYSQL_JAVA_CLIENT_TAG=${DOCKER_MYSQL_JAVA_CLIENT_TAG:=latest}

docs/en/engines/table-engines/mergetree-family/aggregatingmergetree.md

@@ -3,7 +3,7 @@ toc_priority: 35
 toc_title: AggregatingMergeTree
 ---
 
-# Aggregatingmergetree {#aggregatingmergetree}
+# AggregatingMergeTree {#aggregatingmergetree}
 
 The engine inherits from [MergeTree](../../../engines/table-engines/mergetree-family/mergetree.md#table_engines-mergetree), altering the logic for data parts merging. ClickHouse replaces all rows with the same primary key (or more accurately, with the same [sorting key](../../../engines/table-engines/mergetree-family/mergetree.md)) with a single row (within a one data part) that stores a combination of states of aggregate functions.
 

docs/en/interfaces/third-party/gui.md

@@ -184,4 +184,9 @@ SeekTable is [free](https://www.seektable.com/help/cloud-pricing) for personal/i
 
 [How to configure ClickHouse connection in SeekTable.](https://www.seektable.com/help/clickhouse-pivot-table)
 
+
+### Chadmin {#chadmin}
+
+[Chadmin](https://github.com/bun4uk/chadmin) is a simple UI where you can visualize your currently running queries on your ClickHouse cluster and info about them and kill them if you want.
+
 [Original article](https://clickhouse.tech/docs/en/interfaces/third-party/gui/) <!--hide-->

docs/en/introduction/adopters.md

@@ -13,6 +13,7 @@ toc_title: Adopters
 | <a href="https://2gis.ru" class="favicon">2gis</a> | Maps | Monitoring | — | — | [Talk in Russian, July 2019](https://youtu.be/58sPkXfq6nw) |
 | <a href="https://getadmiral.com/" class="favicon">Admiral</a> | Martech | Engagement Management | — | — | [Webinar Slides, June 2020](https://altinity.com/presentations/2020/06/16/big-data-in-real-time-how-clickhouse-powers-admirals-visitor-relationships-for-publishers) |
 | <a href="http://www.adscribe.tv/" class="favicon">AdScribe</a> | Ads | TV Analytics | — | — | [A quote from CTO](https://altinity.com/24x7-support/) |
+| <a href="https://ahrefs.com/" class="favicon">Ahrefs</a> | SEO | Analytics | — | — | [Job listing](https://ahrefs.com/jobs/data-scientist-search) |
 | <a href="https://cn.aliyun.com/" class="favicon">Alibaba Cloud</a> | Cloud | Managed Service | — | — | [Official Website](https://help.aliyun.com/product/144466.html) |
 | <a href="https://alohabrowser.com/" class="favicon">Aloha Browser</a> | Mobile App | Browser backend | — | — | [Slides in Russian, May 2019](https://presentations.clickhouse.tech/meetup22/aloha.pdf) |
 | <a href="https://altinity.com/" class="favicon">Altinity</a> | Cloud, SaaS | Main product | — | — | [Official Website](https://altinity.com/) |

docs/en/operations/settings/settings.md

@@ -2844,4 +2844,15 @@ Sets the interval in seconds after which periodically refreshed [live view](../.
 
 Default value: `60`.
 
+## check_query_single_value_result {#check_query_single_value_result}
+
+Defines the level of detail for the [CHECK TABLE](../../sql-reference/statements/check-table.md#checking-mergetree-tables) query result for `MergeTree` family engines .
+
+Possible values:
+
+-   0 — the query shows a check status for every individual data part of a table.
+-   1 — the query shows the general table check status.
+
+Default value: `0`.
+
 [Original article](https://clickhouse.tech/docs/en/operations/settings/settings/) <!-- hide -->

docs/en/sql-reference/statements/check-table.md

@@ -30,9 +30,36 @@ Performed over the tables with another table engines causes an exception.
 
 Engines from the `*Log` family don’t provide automatic data recovery on failure. Use the `CHECK TABLE` query to track data loss in a timely manner.
 
-For `MergeTree` family engines, the `CHECK TABLE` query shows a check status for every individual data part of a table on the local server.
+## Checking the MergeTree Family Tables {#checking-mergetree-tables}
 
-**If the data is corrupted**
+For `MergeTree` family engines, if [check_query_single_value_result](../../operations/settings/settings.md#check_query_single_value_result) = 0, the `CHECK TABLE` query shows a check status for every individual data part of a table on the local server. 
+
+```sql
+SET check_query_single_value_result = 0;
+CHECK TABLE test_table;
+```
+
+```text
+┌─part_path─┬─is_passed─┬─message─┐
+│ all_1_4_1 │         1 │         │
+│ all_1_4_2 │         1 │         │
+└───────────┴───────────┴─────────┘
+```
+
+If `check_query_single_value_result` = 0, the `CHECK TABLE` query shows the general table check status.
+
+```sql
+SET check_query_single_value_result = 1;
+CHECK TABLE test_table;
+```
+
+```text
+┌─result─┐
+│      1 │
+└────────┘
+```
+
+## If the Data Is Corrupted {#if-data-is-corrupted}
 
 If the table is corrupted, you can copy the non-corrupted data to another table. To do this:
 

docs/ru/operations/settings/settings.md

@@ -2746,4 +2746,15 @@ SELECT * FROM test2;
 
 Значение по умолчанию: `60`.
 
+## check_query_single_value_result {#check_query_single_value_result}
+
+Определяет уровень детализации результата для запросов [CHECK TABLE](../../sql-reference/statements/check-table.md#checking-mergetree-tables) для таблиц семейства `MergeTree`.
+
+Возможные значения:
+
+-   0 — запрос возвращает статус каждого куска данных таблицы.
+-   1 — запрос возвращает статус таблицы в целом.
+
+Значение по умолчанию: `0`.
+
 [Оригинальная статья](https://clickhouse.tech/docs/ru/operations/settings/settings/) <!--hide-->

docs/ru/sql-reference/statements/check-table.md

@@ -29,9 +29,36 @@ CHECK TABLE [db.]name
 
 В движках `*Log` не предусмотрено автоматическое восстановление данных после сбоя. Используйте запрос `CHECK TABLE`, чтобы своевременно выявлять повреждение данных.
 
-Для движков из семейства `MergeTree` запрос `CHECK TABLE` показывает статус проверки для каждого отдельного куска данных таблицы на локальном сервере.
+## Проверка таблиц семейства MergeTree {#checking-mergetree-tables}
 
-**Что делать, если данные повреждены**
+Для таблиц семейства `MergeTree` если [check_query_single_value_result](../../operations/settings/settings.md#check_query_single_value_result) = 0, запрос `CHECK TABLE` возвращает статус каждого куска данных таблицы на локальном сервере. 
+
+```sql
+SET check_query_single_value_result = 0;
+CHECK TABLE test_table;
+```
+
+```text
+┌─part_path─┬─is_passed─┬─message─┐
+│ all_1_4_1 │         1 │         │
+│ all_1_4_2 │         1 │         │
+└───────────┴───────────┴─────────┘
+```
+
+Если `check_query_single_value_result` = 0, запрос `CHECK TABLE` возвращает статус таблицы в целом.
+
+```sql
+SET check_query_single_value_result = 1;
+CHECK TABLE test_table;
+```
+
+```text
+┌─result─┐
+│      1 │
+└────────┘
+```
+
+## Что делать, если данные повреждены {#if-data-is-corrupted}
 
 В этом случае можно скопировать оставшиеся неповрежденные данные в другую таблицу. Для этого:
 

programs/CMakeLists.txt

@@ -36,6 +36,9 @@ option (ENABLE_CLICKHOUSE_OBFUSCATOR "Table data obfuscator (convert real data t
 option (ENABLE_CLICKHOUSE_ODBC_BRIDGE "HTTP-server working like a proxy to ODBC driver"
     ${ENABLE_CLICKHOUSE_ALL})
 
+option (ENABLE_CLICKHOUSE_LIBRARY_BRIDGE "HTTP-server working like a proxy to Library dictionary source"
+    ${ENABLE_CLICKHOUSE_ALL})
+
 # https://presentations.clickhouse.tech/matemarketing_2020/
 option (ENABLE_CLICKHOUSE_GIT_IMPORT "A tool to analyze Git repositories"
     ${ENABLE_CLICKHOUSE_ALL})
@@ -109,6 +112,12 @@ else()
     message(STATUS "ODBC bridge mode: OFF")
 endif()
 
+if (ENABLE_CLICKHOUSE_LIBRARY_BRIDGE)
+    message(STATUS "Library bridge mode: ON")
+else()
+    message(STATUS "Library bridge mode: OFF")
+endif()
+
 if (ENABLE_CLICKHOUSE_INSTALL)
     message(STATUS "ClickHouse install: ON")
 else()
@@ -194,6 +203,10 @@ if (ENABLE_CLICKHOUSE_ODBC_BRIDGE)
     add_subdirectory (odbc-bridge)
 endif ()
 
+if (ENABLE_CLICKHOUSE_LIBRARY_BRIDGE)
+    add_subdirectory (library-bridge)
+endif ()
+
 if (CLICKHOUSE_ONE_SHARED)
     add_library(clickhouse-lib SHARED ${CLICKHOUSE_SERVER_SOURCES} ${CLICKHOUSE_CLIENT_SOURCES} ${CLICKHOUSE_LOCAL_SOURCES} ${CLICKHOUSE_BENCHMARK_SOURCES} ${CLICKHOUSE_COPIER_SOURCES} ${CLICKHOUSE_EXTRACT_FROM_CONFIG_SOURCES} ${CLICKHOUSE_COMPRESSOR_SOURCES} ${CLICKHOUSE_FORMAT_SOURCES} ${CLICKHOUSE_OBFUSCATOR_SOURCES} ${CLICKHOUSE_GIT_IMPORT_SOURCES} ${CLICKHOUSE_ODBC_BRIDGE_SOURCES})
     target_link_libraries(clickhouse-lib ${CLICKHOUSE_SERVER_LINK} ${CLICKHOUSE_CLIENT_LINK} ${CLICKHOUSE_LOCAL_LINK} ${CLICKHOUSE_BENCHMARK_LINK} ${CLICKHOUSE_COPIER_LINK} ${CLICKHOUSE_EXTRACT_FROM_CONFIG_LINK} ${CLICKHOUSE_COMPRESSOR_LINK} ${CLICKHOUSE_FORMAT_LINK} ${CLICKHOUSE_OBFUSCATOR_LINK} ${CLICKHOUSE_GIT_IMPORT_LINK} ${CLICKHOUSE_ODBC_BRIDGE_LINK})
@@ -209,6 +222,10 @@ if (CLICKHOUSE_SPLIT_BINARY)
         list (APPEND CLICKHOUSE_ALL_TARGETS clickhouse-odbc-bridge)
     endif ()
 
+    if (ENABLE_CLICKHOUSE_LIBRARY_BRIDGE)
+        list (APPEND CLICKHOUSE_ALL_TARGETS clickhouse-library-bridge)
+    endif ()
+
     set_target_properties(${CLICKHOUSE_ALL_TARGETS} PROPERTIES RUNTIME_OUTPUT_DIRECTORY ..)
 
     add_custom_target (clickhouse-bundle ALL DEPENDS ${CLICKHOUSE_ALL_TARGETS})

programs/config_tools.h.in

@@ -15,3 +15,4 @@
 #cmakedefine01 ENABLE_CLICKHOUSE_GIT_IMPORT
 #cmakedefine01 ENABLE_CLICKHOUSE_INSTALL
 #cmakedefine01 ENABLE_CLICKHOUSE_ODBC_BRIDGE
+#cmakedefine01 ENABLE_CLICKHOUSE_LIBRARY_BRIDGE

programs/library-bridge/CMakeLists.txt

@@ -0,0 +1,26 @@
+set (CLICKHOUSE_LIBRARY_BRIDGE_SOURCES
+    library-bridge.cpp
+    library-log.cpp
+    LibraryBridge.cpp
+    Handlers.cpp
+    HandlerFactory.cpp
+    SharedLibraryHandler.cpp
+    SharedLibraryHandlerFactory.cpp
+)
+
+if (OS_LINUX)
+    set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--no-export-dynamic")
+endif ()
+
+add_executable(clickhouse-library-bridge ${CLICKHOUSE_LIBRARY_BRIDGE_SOURCES})
+
+target_link_libraries(clickhouse-library-bridge PRIVATE
+    daemon
+    dbms
+    clickhouse_parsers
+    bridge
+)
+
+set_target_properties(clickhouse-library-bridge PROPERTIES RUNTIME_OUTPUT_DIRECTORY ..)
+
+install(TARGETS clickhouse-library-bridge RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT clickhouse)

programs/library-bridge/HandlerFactory.cpp

@@ -0,0 +1,23 @@
+#include "HandlerFactory.h"
+
+#include <Poco/Net/HTTPServerRequest.h>
+#include <Server/HTTP/HTMLForm.h>
+#include "Handlers.h"
+
+
+namespace DB
+{
+    std::unique_ptr<HTTPRequestHandler> LibraryBridgeHandlerFactory::createRequestHandler(const HTTPServerRequest & request)
+    {
+        Poco::URI uri{request.getURI()};
+        LOG_DEBUG(log, "Request URI: {}", uri.toString());
+
+        if (uri == "/ping" && request.getMethod() == Poco::Net::HTTPRequest::HTTP_GET)
+            return std::make_unique<PingHandler>(keep_alive_timeout);
+
+        if (request.getMethod() == Poco::Net::HTTPRequest::HTTP_POST)
+            return std::make_unique<LibraryRequestHandler>(keep_alive_timeout, context);
+
+        return nullptr;
+    }
+}

programs/library-bridge/HandlerFactory.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <Interpreters/Context.h>
+#include <Server/HTTP/HTTPRequestHandlerFactory.h>
+#include <common/logger_useful.h>
+
+
+namespace DB
+{
+
+class SharedLibraryHandler;
+using SharedLibraryHandlerPtr = std::shared_ptr<SharedLibraryHandler>;
+
+/// Factory for '/ping', '/' handlers.
+class LibraryBridgeHandlerFactory : public HTTPRequestHandlerFactory
+{
+public:
+    LibraryBridgeHandlerFactory(
+            const std::string & name_,
+            size_t keep_alive_timeout_,
+            Context & context_)
+        : log(&Poco::Logger::get(name_))
+        , name(name_)
+        , keep_alive_timeout(keep_alive_timeout_)
+        , context(context_)
+    {
+    }
+
+    std::unique_ptr<HTTPRequestHandler> createRequestHandler(const HTTPServerRequest & request) override;
+
+private:
+    Poco::Logger * log;
+    std::string name;
+    size_t keep_alive_timeout;
+    Context & context;
+};
+
+}

programs/library-bridge/Handlers.cpp

@@ -0,0 +1,288 @@
+#include "Handlers.h"
+#include "SharedLibraryHandlerFactory.h"
+
+#include <DataStreams/copyData.h>
+#include <Formats/FormatFactory.h>
+#include <Server/HTTP/WriteBufferFromHTTPServerResponse.h>
+#include <IO/WriteHelpers.h>
+#include <IO/ReadHelpers.h>
+#include <Poco/Net/HTTPServerRequest.h>
+#include <Poco/Net/HTTPServerResponse.h>
+#include <Poco/Net/HTMLForm.h>
+#include <Poco/ThreadPool.h>
+#include <Processors/Formats/InputStreamFromInputFormat.h>
+#include <Server/HTTP/HTMLForm.h>
+#include <IO/ReadBufferFromString.h>
+
+
+namespace DB
+{
+namespace
+{
+    std::shared_ptr<Block> parseColumns(std::string && column_string)
+    {
+        auto sample_block = std::make_shared<Block>();
+        auto names_and_types = NamesAndTypesList::parse(column_string);
+
+        for (const NameAndTypePair & column_data : names_and_types)
+            sample_block->insert({column_data.type, column_data.name});
+
+        return sample_block;
+    }
+
+    std::vector<uint64_t> parseIdsFromBinary(const std::string & ids_string)
+    {
+        ReadBufferFromString buf(ids_string);
+        std::vector<uint64_t> ids;
+        readVectorBinary(ids, buf);
+        return ids;
+    }
+
+    std::vector<std::string> parseNamesFromBinary(const std::string & names_string)
+    {
+        ReadBufferFromString buf(names_string);
+        std::vector<std::string> names;
+        readVectorBinary(names, buf);
+        return names;
+    }
+}
+
+
+void LibraryRequestHandler::handleRequest(HTTPServerRequest & request, HTTPServerResponse & response)
+{
+    LOG_TRACE(log, "Request URI: {}", request.getURI());
+    HTMLForm params(request);
+
+    if (!params.has("method"))
+    {
+        processError(response, "No 'method' in request URL");
+        return;
+    }
+
+    if (!params.has("dictionary_id"))
+    {
+        processError(response, "No 'dictionary_id in request URL");
+        return;
+    }
+
+    std::string method = params.get("method");
+    std::string dictionary_id = params.get("dictionary_id");
+    LOG_TRACE(log, "Library method: '{}', dictionary id: {}", method, dictionary_id);
+
+    WriteBufferFromHTTPServerResponse out(response, request.getMethod() == Poco::Net::HTTPRequest::HTTP_HEAD, keep_alive_timeout);
+
+    try
+    {
+        if (method == "libNew")
+        {
+            auto & read_buf = request.getStream();
+            params.read(read_buf);
+
+            if (!params.has("library_path"))
+            {
+                processError(response, "No 'library_path' in request URL");
+                return;
+            }
+
+            if (!params.has("library_settings"))
+            {
+                processError(response, "No 'library_settings' in request URL");
+                return;
+            }
+
+            std::string library_path = params.get("library_path");
+            const auto & settings_string = params.get("library_settings");
+            std::vector<std::string> library_settings = parseNamesFromBinary(settings_string);
+
+            /// Needed for library dictionary
+            if (!params.has("attributes_names"))
+            {
+                processError(response, "No 'attributes_names' in request URL");
+                return;
+            }
+
+            const auto & attributes_string = params.get("attributes_names");
+            std::vector<std::string> attributes_names = parseNamesFromBinary(attributes_string);
+
+            /// Needed to parse block from binary string format
+            if (!params.has("sample_block"))
+            {
+                processError(response, "No 'sample_block' in request URL");
+                return;
+            }
+            std::string sample_block_string = params.get("sample_block");
+
+            std::shared_ptr<Block> sample_block;
+            try
+            {
+                sample_block = parseColumns(std::move(sample_block_string));
+            }
+            catch (const Exception & ex)
+            {
+                processError(response, "Invalid 'sample_block' parameter in request body '" + ex.message() + "'");
+                LOG_WARNING(log, ex.getStackTraceString());
+                return;
+            }
+
+            if (!params.has("null_values"))
+            {
+                processError(response, "No 'null_values' in request URL");
+                return;
+            }
+
+            ReadBufferFromString read_block_buf(params.get("null_values"));
+            auto format = FormatFactory::instance().getInput(FORMAT, read_block_buf, *sample_block, context, DEFAULT_BLOCK_SIZE);
+            auto reader = std::make_shared<InputStreamFromInputFormat>(format);
+            auto sample_block_with_nulls = reader->read();
+
+            LOG_DEBUG(log, "Dictionary sample block with null values: {}", sample_block_with_nulls.dumpStructure());
+
+            SharedLibraryHandlerFactory::instance().create(dictionary_id, library_path, library_settings, sample_block_with_nulls, attributes_names);
+            writeStringBinary("1", out);
+        }
+        else if (method == "libClone")
+        {
+            if (!params.has("from_dictionary_id"))
+            {
+                processError(response, "No 'from_dictionary_id' in request URL");
+                return;
+            }
+
+            std::string from_dictionary_id = params.get("from_dictionary_id");
+            LOG_TRACE(log, "Calling libClone from {} to {}", from_dictionary_id, dictionary_id);
+            SharedLibraryHandlerFactory::instance().clone(from_dictionary_id, dictionary_id);
+            writeStringBinary("1", out);
+        }
+        else if (method == "libDelete")
+        {
+            SharedLibraryHandlerFactory::instance().remove(dictionary_id);
+            writeStringBinary("1", out);
+        }
+        else if (method == "isModified")
+        {
+            auto library_handler = SharedLibraryHandlerFactory::instance().get(dictionary_id);
+            bool res = library_handler->isModified();
+            writeStringBinary(std::to_string(res), out);
+        }
+        else if (method == "supportsSelectiveLoad")
+        {
+            auto library_handler = SharedLibraryHandlerFactory::instance().get(dictionary_id);
+            bool res = library_handler->supportsSelectiveLoad();
+            writeStringBinary(std::to_string(res), out);
+        }
+        else if (method == "loadAll")
+        {
+            auto library_handler = SharedLibraryHandlerFactory::instance().get(dictionary_id);
+            const auto & sample_block = library_handler->getSampleBlock();
+            auto input = library_handler->loadAll();
+
+            BlockOutputStreamPtr output = FormatFactory::instance().getOutputStream(FORMAT, out, sample_block, context);
+            copyData(*input, *output);
+        }
+        else if (method == "loadIds")
+        {
+            params.read(request.getStream());
+
+            if (!params.has("ids"))
+            {
+                processError(response, "No 'ids' in request URL");
+                return;
+            }
+
+            std::vector<uint64_t> ids = parseIdsFromBinary(params.get("ids"));
+            auto library_handler = SharedLibraryHandlerFactory::instance().get(dictionary_id);
+            const auto & sample_block = library_handler->getSampleBlock();
+            auto input = library_handler->loadIds(ids);
+            BlockOutputStreamPtr output = FormatFactory::instance().getOutputStream(FORMAT, out, sample_block, context);
+            copyData(*input, *output);
+        }
+        else if (method == "loadKeys")
+        {
+            if (!params.has("requested_block_sample"))
+            {
+                processError(response, "No 'requested_block_sample' in request URL");
+                return;
+            }
+
+            std::string requested_block_string = params.get("requested_block_sample");
+
+            std::shared_ptr<Block> requested_sample_block;
+            try
+            {
+                requested_sample_block = parseColumns(std::move(requested_block_string));
+            }
+            catch (const Exception & ex)
+            {
+                processError(response, "Invalid 'requested_block' parameter in request body '" + ex.message() + "'");
+                LOG_WARNING(log, ex.getStackTraceString());
+                return;
+            }
+
+            auto & read_buf = request.getStream();
+            auto format = FormatFactory::instance().getInput(FORMAT, read_buf, *requested_sample_block, context, DEFAULT_BLOCK_SIZE);
+            auto reader = std::make_shared<InputStreamFromInputFormat>(format);
+            auto block = reader->read();
+
+            auto library_handler = SharedLibraryHandlerFactory::instance().get(dictionary_id);
+            const auto & sample_block = library_handler->getSampleBlock();
+            auto input = library_handler->loadKeys(block.getColumns());
+            BlockOutputStreamPtr output = FormatFactory::instance().getOutputStream(FORMAT, out, sample_block, context);
+            copyData(*input, *output);
+        }
+    }
+    catch (...)
+    {
+        auto message = getCurrentExceptionMessage(true);
+        response.setStatusAndReason(Poco::Net::HTTPResponse::HTTP_INTERNAL_SERVER_ERROR, message); // can't call process_error, because of too soon response sending
+
+        try
+        {
+            writeStringBinary(message, out);
+            out.finalize();
+        }
+        catch (...)
+        {
+            tryLogCurrentException(log);
+        }
+
+        tryLogCurrentException(log);
+    }
+
+    try
+    {
+        out.finalize();
+    }
+    catch (...)
+    {
+        tryLogCurrentException(log);
+    }
+}
+
+
+void LibraryRequestHandler::processError(HTTPServerResponse & response, const std::string & message)
+{
+    response.setStatusAndReason(HTTPResponse::HTTP_INTERNAL_SERVER_ERROR);
+
+    if (!response.sent())
+        *response.send() << message << std::endl;
+
+    LOG_WARNING(log, message);
+}
+
+
+void PingHandler::handleRequest(HTTPServerRequest & /* request */, HTTPServerResponse & response)
+{
+    try
+    {
+        setResponseDefaultHeaders(response, keep_alive_timeout);
+        const char * data = "Ok.\n";
+        response.sendBuffer(data, strlen(data));
+    }
+    catch (...)
+    {
+        tryLogCurrentException("PingHandler");
+    }
+}
+
+
+}

programs/library-bridge/Handlers.h

@@ -0,0 +1,60 @@
+#pragma once
+
+#include <Interpreters/Context.h>
+#include <Server/HTTP/HTTPRequestHandler.h>
+#include <common/logger_useful.h>
+#include "SharedLibraryHandler.h"
+
+
+namespace DB
+{
+
+
+/// Handler for requests to Library Dictionary Source, returns response in RowBinary format.
+/// When a library dictionary source is created, it sends libNew request to library bridge (which is started on first
+/// request to it, if it was not yet started). On this request a new sharedLibrayHandler is added to a
+/// sharedLibraryHandlerFactory by a dictionary uuid. With libNew request come: library_path, library_settings,
+/// names of dictionary attributes, sample block to parse block of null values, block of null values. Everything is
+/// passed in binary format and is urlencoded. When dictionary is cloned, a new handler is created.
+/// Each handler is unique to dictionary.
+class LibraryRequestHandler : public HTTPRequestHandler
+{
+public:
+
+    LibraryRequestHandler(
+        size_t keep_alive_timeout_,
+        Context & context_)
+        : log(&Poco::Logger::get("LibraryRequestHandler"))
+        , keep_alive_timeout(keep_alive_timeout_)
+        , context(context_)
+    {
+    }
+
+    void handleRequest(HTTPServerRequest & request, HTTPServerResponse & response) override;
+
+private:
+    static constexpr inline auto FORMAT = "RowBinary";
+
+    void processError(HTTPServerResponse & response, const std::string & message);
+
+    Poco::Logger * log;
+    size_t keep_alive_timeout;
+    Context & context;
+};
+
+
+class PingHandler : public HTTPRequestHandler
+{
+public:
+    explicit PingHandler(size_t keep_alive_timeout_)
+        : keep_alive_timeout(keep_alive_timeout_)
+    {
+    }
+
+    void handleRequest(HTTPServerRequest & request, HTTPServerResponse & response) override;
+
+private:
+    const size_t keep_alive_timeout;
+};
+
+}

programs/library-bridge/LibraryBridge.cpp

@@ -0,0 +1,17 @@
+#include "LibraryBridge.h"
+
+#pragma GCC diagnostic ignored "-Wmissing-declarations"
+int mainEntryClickHouseLibraryBridge(int argc, char ** argv)
+{
+    DB::LibraryBridge app;
+    try
+    {
+        return app.run(argc, argv);
+    }
+    catch (...)
+    {
+        std::cerr << DB::getCurrentExceptionMessage(true) << "\n";
+        auto code = DB::getCurrentExceptionCode();
+        return code ? code : 1;
+    }
+}

programs/library-bridge/LibraryBridge.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <Interpreters/Context.h>
+#include <bridge/IBridge.h>
+#include "HandlerFactory.h"
+
+
+namespace DB
+{
+
+class LibraryBridge : public IBridge
+{
+
+protected:
+    const std::string bridgeName() const override
+    {
+        return "LibraryBridge";
+    }
+
+    HandlerFactoryPtr getHandlerFactoryPtr(Context & context) const override
+    {
+        return std::make_shared<LibraryBridgeHandlerFactory>("LibraryRequestHandlerFactory-factory", keep_alive_timeout, context);
+    }
+};
+
+}

programs/library-bridge/LibraryUtils.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <Common/StringUtils/StringUtils.h>
+#include <Dictionaries/LibraryDictionarySourceExternal.h>
+#include <Core/Block.h>
+#include <ext/bit_cast.h>
+#include <ext/range.h>
+
+
+namespace DB
+{
+
+class CStringsHolder
+{
+
+public:
+    using Container = std::vector<std::string>;
+
+    explicit CStringsHolder(const Container & strings_pass)
+    {
+        strings_holder = strings_pass;
+        strings.size = strings_holder.size();
+
+        ptr_holder = std::make_unique<ClickHouseLibrary::CString[]>(strings.size);
+        strings.data = ptr_holder.get();
+
+        size_t i = 0;
+        for (auto & str : strings_holder)
+        {
+            strings.data[i] = str.c_str();
+            ++i;
+        }
+    }
+
+    ClickHouseLibrary::CStrings strings; // will pass pointer to lib
+
+private:
+    std::unique_ptr<ClickHouseLibrary::CString[]> ptr_holder = nullptr;
+    Container strings_holder;
+};
+
+
+}

programs/library-bridge/SharedLibraryHandler.cpp

@@ -0,0 +1,219 @@
+#include "SharedLibraryHandler.h"
+
+#include <ext/scope_guard.h>
+#include <IO/ReadHelpers.h>
+#include <common/find_symbols.h>
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+    extern const int EXTERNAL_LIBRARY_ERROR;
+    extern const int SIZES_OF_COLUMNS_DOESNT_MATCH;
+}
+
+
+SharedLibraryHandler::SharedLibraryHandler(
+    const std::string & library_path_,
+    const std::vector<std::string> & library_settings,
+    const Block & sample_block_,
+    const std::vector<std::string> & attributes_names_)
+    : library_path(library_path_)
+    , sample_block(sample_block_)
+    , attributes_names(attributes_names_)
+{
+    library = std::make_shared<SharedLibrary>(library_path, RTLD_LAZY);
+    settings_holder = std::make_shared<CStringsHolder>(CStringsHolder(library_settings));
+
+    auto lib_new = library->tryGet<ClickHouseLibrary::LibraryNewFunc>(ClickHouseLibrary::LIBRARY_CREATE_NEW_FUNC_NAME);
+
+    if (lib_new)
+        lib_data = lib_new(&settings_holder->strings, ClickHouseLibrary::log);
+    else
+        throw Exception("Method libNew failed", ErrorCodes::EXTERNAL_LIBRARY_ERROR);
+}
+
+
+SharedLibraryHandler::SharedLibraryHandler(const SharedLibraryHandler & other)
+    : library_path{other.library_path}
+    , sample_block{other.sample_block}
+    , attributes_names{other.attributes_names}
+    , library{other.library}
+    , settings_holder{other.settings_holder}
+{
+
+    auto lib_clone = library->tryGet<ClickHouseLibrary::LibraryCloneFunc>(ClickHouseLibrary::LIBRARY_CLONE_FUNC_NAME);
+
+    if (lib_clone)
+    {
+        lib_data = lib_clone(other.lib_data);
+    }
+    else
+    {
+        auto lib_new = library->tryGet<ClickHouseLibrary::LibraryNewFunc>(ClickHouseLibrary::LIBRARY_CREATE_NEW_FUNC_NAME);
+
+        if (lib_new)
+            lib_data = lib_new(&settings_holder->strings, ClickHouseLibrary::log);
+    }
+}
+
+
+SharedLibraryHandler::~SharedLibraryHandler()
+{
+    auto lib_delete = library->tryGet<ClickHouseLibrary::LibraryDeleteFunc>(ClickHouseLibrary::LIBRARY_DELETE_FUNC_NAME);
+
+    if (lib_delete)
+        lib_delete(lib_data);
+}
+
+
+bool SharedLibraryHandler::isModified()
+{
+    auto func_is_modified = library->tryGet<ClickHouseLibrary::LibraryIsModifiedFunc>(ClickHouseLibrary::LIBRARY_IS_MODIFIED_FUNC_NAME);
+
+    if (func_is_modified)
+        return func_is_modified(lib_data, &settings_holder->strings);
+
+    return true;
+}
+
+
+bool SharedLibraryHandler::supportsSelectiveLoad()
+{
+    auto func_supports_selective_load = library->tryGet<ClickHouseLibrary::LibrarySupportsSelectiveLoadFunc>(ClickHouseLibrary::LIBRARY_SUPPORTS_SELECTIVE_LOAD_FUNC_NAME);
+
+    if (func_supports_selective_load)
+        return func_supports_selective_load(lib_data, &settings_holder->strings);
+
+    return true;
+}
+
+
+BlockInputStreamPtr SharedLibraryHandler::loadAll()
+{
+    auto columns_holder = std::make_unique<ClickHouseLibrary::CString[]>(attributes_names.size());
+    ClickHouseLibrary::CStrings columns{static_cast<decltype(ClickHouseLibrary::CStrings::data)>(columns_holder.get()), attributes_names.size()};
+    for (size_t i = 0; i < attributes_names.size(); ++i)
+        columns.data[i] = attributes_names[i].c_str();
+
+    auto load_all_func = library->get<ClickHouseLibrary::LibraryLoadAllFunc>(ClickHouseLibrary::LIBRARY_LOAD_ALL_FUNC_NAME);
+    auto data_new_func = library->get<ClickHouseLibrary::LibraryDataNewFunc>(ClickHouseLibrary::LIBRARY_DATA_NEW_FUNC_NAME);
+    auto data_delete_func = library->get<ClickHouseLibrary::LibraryDataDeleteFunc>(ClickHouseLibrary::LIBRARY_DATA_DELETE_FUNC_NAME);
+
+    ClickHouseLibrary::LibraryData data_ptr = data_new_func(lib_data);
+    SCOPE_EXIT(data_delete_func(lib_data, data_ptr));
+
+    ClickHouseLibrary::RawClickHouseLibraryTable data = load_all_func(data_ptr, &settings_holder->strings, &columns);
+    auto block = dataToBlock(data);
+
+    return std::make_shared<OneBlockInputStream>(block);
+}
+
+
+BlockInputStreamPtr SharedLibraryHandler::loadIds(const std::vector<uint64_t> & ids)
+{
+    const ClickHouseLibrary::VectorUInt64 ids_data{ext::bit_cast<decltype(ClickHouseLibrary::VectorUInt64::data)>(ids.data()), ids.size()};
+
+    auto columns_holder = std::make_unique<ClickHouseLibrary::CString[]>(attributes_names.size());
+    ClickHouseLibrary::CStrings columns_pass{static_cast<decltype(ClickHouseLibrary::CStrings::data)>(columns_holder.get()), attributes_names.size()};
+
+    auto load_ids_func = library->get<ClickHouseLibrary::LibraryLoadIdsFunc>(ClickHouseLibrary::LIBRARY_LOAD_IDS_FUNC_NAME);
+    auto data_new_func = library->get<ClickHouseLibrary::LibraryDataNewFunc>(ClickHouseLibrary::LIBRARY_DATA_NEW_FUNC_NAME);
+    auto data_delete_func = library->get<ClickHouseLibrary::LibraryDataDeleteFunc>(ClickHouseLibrary::LIBRARY_DATA_DELETE_FUNC_NAME);
+
+    ClickHouseLibrary::LibraryData data_ptr = data_new_func(lib_data);
+    SCOPE_EXIT(data_delete_func(lib_data, data_ptr));
+
+    ClickHouseLibrary::RawClickHouseLibraryTable data = load_ids_func(data_ptr, &settings_holder->strings, &columns_pass, &ids_data);
+    auto block = dataToBlock(data);
+
+    return std::make_shared<OneBlockInputStream>(block);
+}
+
+
+BlockInputStreamPtr SharedLibraryHandler::loadKeys(const Columns & key_columns)
+{
+    auto holder = std::make_unique<ClickHouseLibrary::Row[]>(key_columns.size());
+    std::vector<std::unique_ptr<ClickHouseLibrary::Field[]>> column_data_holders;
+
+    for (size_t i = 0; i < key_columns.size(); ++i)
+    {
+        auto cell_holder = std::make_unique<ClickHouseLibrary::Field[]>(key_columns[i]->size());
+
+        for (size_t j = 0; j < key_columns[i]->size(); ++j)
+        {
+            auto data_ref = key_columns[i]->getDataAt(j);
+
+            cell_holder[j] = ClickHouseLibrary::Field{
+                    .data = static_cast<const void *>(data_ref.data),
+                    .size = data_ref.size};
+        }
+
+        holder[i] = ClickHouseLibrary::Row{
+                    .data = static_cast<ClickHouseLibrary::Field *>(cell_holder.get()),
+                    .size = key_columns[i]->size()};
+
+        column_data_holders.push_back(std::move(cell_holder));
+    }
+
+    ClickHouseLibrary::Table request_cols{
+            .data = static_cast<ClickHouseLibrary::Row *>(holder.get()),
+            .size = key_columns.size()};
+
+    auto load_keys_func = library->get<ClickHouseLibrary::LibraryLoadKeysFunc>(ClickHouseLibrary::LIBRARY_LOAD_KEYS_FUNC_NAME);
+    auto data_new_func = library->get<ClickHouseLibrary::LibraryDataNewFunc>(ClickHouseLibrary::LIBRARY_DATA_NEW_FUNC_NAME);
+    auto data_delete_func = library->get<ClickHouseLibrary::LibraryDataDeleteFunc>(ClickHouseLibrary::LIBRARY_DATA_DELETE_FUNC_NAME);
+
+    ClickHouseLibrary::LibraryData data_ptr = data_new_func(lib_data);
+    SCOPE_EXIT(data_delete_func(lib_data, data_ptr));
+
+    ClickHouseLibrary::RawClickHouseLibraryTable data = load_keys_func(data_ptr, &settings_holder->strings, &request_cols);
+    auto block = dataToBlock(data);
+
+    return std::make_shared<OneBlockInputStream>(block);
+}
+
+
+Block SharedLibraryHandler::dataToBlock(const ClickHouseLibrary::RawClickHouseLibraryTable data)
+{
+    if (!data)
+        throw Exception("LibraryDictionarySource: No data returned", ErrorCodes::EXTERNAL_LIBRARY_ERROR);
+
+    const auto * columns_received = static_cast<const ClickHouseLibrary::Table *>(data);
+    if (columns_received->error_code)
+        throw Exception(
+            "LibraryDictionarySource: Returned error: " + std::to_string(columns_received->error_code) + " " + (columns_received->error_string ? columns_received->error_string : ""),
+            ErrorCodes::EXTERNAL_LIBRARY_ERROR);
+
+    MutableColumns columns = sample_block.cloneEmptyColumns();
+
+    for (size_t col_n = 0; col_n < columns_received->size; ++col_n)
+    {
+        if (columns.size() != columns_received->data[col_n].size)
+            throw Exception(
+                "LibraryDictionarySource: Returned unexpected number of columns: " + std::to_string(columns_received->data[col_n].size) + ", must be " + std::to_string(columns.size()),
+                ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
+
+        for (size_t row_n = 0; row_n < columns_received->data[col_n].size; ++row_n)
+        {
+            const auto & field = columns_received->data[col_n].data[row_n];
+            if (!field.data)
+            {
+                /// sample_block contains null_value (from config) inside corresponding column
+                const auto & col = sample_block.getByPosition(row_n);
+                columns[row_n]->insertFrom(*(col.column), 0);
+            }
+            else
+            {
+                const auto & size = field.size;
+                columns[row_n]->insertData(static_cast<const char *>(field.data), size);
+            }
+        }
+    }
+
+    return sample_block.cloneWithColumns(std::move(columns));
+}
+
+}

programs/library-bridge/SharedLibraryHandler.h

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <Common/SharedLibrary.h>
+#include <common/logger_useful.h>
+#include <DataStreams/OneBlockInputStream.h>
+#include "LibraryUtils.h"
+
+
+namespace DB
+{
+
+/// A class that manages all operations with library dictionary.
+/// Every library dictionary source has its own object of this class, accessed by UUID.
+class SharedLibraryHandler
+{
+
+public:
+    SharedLibraryHandler(
+        const std::string & library_path_,
+        const std::vector<std::string> & library_settings,
+        const Block & sample_block_,
+        const std::vector<std::string> & attributes_names_);
+
+    SharedLibraryHandler(const SharedLibraryHandler & other);
+
+    ~SharedLibraryHandler();
+
+    BlockInputStreamPtr loadAll();
+
+    BlockInputStreamPtr loadIds(const std::vector<uint64_t> & ids);
+
+    BlockInputStreamPtr loadKeys(const Columns & key_columns);
+
+    bool isModified();
+
+    bool supportsSelectiveLoad();
+
+    const Block & getSampleBlock() { return sample_block; }
+
+private:
+    Block dataToBlock(const ClickHouseLibrary::RawClickHouseLibraryTable data);
+
+    std::string library_path;
+    const Block sample_block;
+    std::vector<std::string> attributes_names;
+
+    SharedLibraryPtr library;
+    std::shared_ptr<CStringsHolder> settings_holder;
+    void * lib_data;
+};
+
+using SharedLibraryHandlerPtr = std::shared_ptr<SharedLibraryHandler>;
+
+}

programs/library-bridge/SharedLibraryHandlerFactory.cpp

@@ -0,0 +1,67 @@
+#include "SharedLibraryHandlerFactory.h"
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+    extern const int LOGICAL_ERROR;
+}
+
+SharedLibraryHandlerPtr SharedLibraryHandlerFactory::get(const std::string & dictionary_id)
+{
+    std::lock_guard lock(mutex);
+    auto library_handler = library_handlers.find(dictionary_id);
+
+    if (library_handler != library_handlers.end())
+        return library_handler->second;
+
+    return nullptr;
+}
+
+
+void SharedLibraryHandlerFactory::create(
+    const std::string & dictionary_id,
+    const std::string & library_path,
+    const std::vector<std::string> & library_settings,
+    const Block & sample_block,
+    const std::vector<std::string> & attributes_names)
+{
+    std::lock_guard lock(mutex);
+    library_handlers[dictionary_id] = std::make_shared<SharedLibraryHandler>(library_path, library_settings, sample_block, attributes_names);
+}
+
+
+void SharedLibraryHandlerFactory::clone(const std::string & from_dictionary_id, const std::string & to_dictionary_id)
+{
+    std::lock_guard lock(mutex);
+    auto from_library_handler = library_handlers.find(from_dictionary_id);
+
+    /// This is not supposed to happen as libClone is called from copy constructor of LibraryDictionarySource
+    /// object, and shared library handler of from_dictionary is removed only in its destructor.
+    /// And if for from_dictionary there was no shared library handler, it would have received and exception in
+    /// its constructor, so no libClone would be made from it.
+    if (from_library_handler == library_handlers.end())
+        throw Exception(ErrorCodes::LOGICAL_ERROR, "No shared library handler found");
+
+    /// libClone method will be called in copy constructor
+    library_handlers[to_dictionary_id] = std::make_shared<SharedLibraryHandler>(*from_library_handler->second);
+}
+
+
+void SharedLibraryHandlerFactory::remove(const std::string & dictionary_id)
+{
+    std::lock_guard lock(mutex);
+    /// libDelete is called in destructor.
+    library_handlers.erase(dictionary_id);
+}
+
+
+SharedLibraryHandlerFactory & SharedLibraryHandlerFactory::instance()
+{
+    static SharedLibraryHandlerFactory ret;
+    return ret;
+}
+
+}

programs/library-bridge/SharedLibraryHandlerFactory.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include "SharedLibraryHandler.h"
+#include <unordered_map>
+#include <mutex>
+
+
+namespace DB
+{
+
+/// Each library dictionary source has unique UUID. When clone() method is called, a new UUID is generated.
+/// There is a unique mapping from diciotnary UUID to sharedLibraryHandler.
+class SharedLibraryHandlerFactory final : private boost::noncopyable
+{
+public:
+    static SharedLibraryHandlerFactory & instance();
+
+    SharedLibraryHandlerPtr get(const std::string & dictionary_id);
+
+    void create(
+        const std::string & dictionary_id,
+        const std::string & library_path,
+        const std::vector<std::string> & library_settings,
+        const Block & sample_block,
+        const std::vector<std::string> & attributes_names);
+
+    void clone(const std::string & from_dictionary_id, const std::string & to_dictionary_id);
+
+    void remove(const std::string & dictionary_id);
+
+private:
+    /// map: dict_id -> sharedLibraryHandler
+    std::unordered_map<std::string, SharedLibraryHandlerPtr> library_handlers;
+    std::mutex mutex;
+};
+
+}

programs/library-bridge/library-bridge.cpp

@@ -0,0 +1,3 @@
+int mainEntryClickHouseLibraryBridge(int argc, char ** argv);
+int main(int argc_, char ** argv_) { return mainEntryClickHouseLibraryBridge(argc_, argv_); }
+

programs/library-bridge/library-log.cpp

@@ -0,0 +1,66 @@
+#include <Dictionaries/LibraryDictionarySourceExternal.h>
+#include <common/logger_useful.h>
+
+namespace
+{
+const char DICT_LOGGER_NAME[] = "LibraryDictionarySourceExternal";
+}
+
+namespace ClickHouseLibrary
+{
+
+std::string_view LIBRARY_CREATE_NEW_FUNC_NAME = "ClickHouseDictionary_v3_libNew";
+std::string_view LIBRARY_CLONE_FUNC_NAME = "ClickHouseDictionary_v3_libClone";
+std::string_view LIBRARY_DELETE_FUNC_NAME = "ClickHouseDictionary_v3_libDelete";
+
+std::string_view LIBRARY_DATA_NEW_FUNC_NAME = "ClickHouseDictionary_v3_dataNew";
+std::string_view LIBRARY_DATA_DELETE_FUNC_NAME = "ClickHouseDictionary_v3_dataDelete";
+
+std::string_view LIBRARY_LOAD_ALL_FUNC_NAME = "ClickHouseDictionary_v3_loadAll";
+std::string_view LIBRARY_LOAD_IDS_FUNC_NAME = "ClickHouseDictionary_v3_loadIds";
+std::string_view LIBRARY_LOAD_KEYS_FUNC_NAME = "ClickHouseDictionary_v3_loadKeys";
+
+std::string_view LIBRARY_IS_MODIFIED_FUNC_NAME = "ClickHouseDictionary_v3_isModified";
+std::string_view LIBRARY_SUPPORTS_SELECTIVE_LOAD_FUNC_NAME = "ClickHouseDictionary_v3_supportsSelectiveLoad";
+
+void log(LogLevel level, CString msg)
+{
+    auto & logger = Poco::Logger::get(DICT_LOGGER_NAME);
+    switch (level)
+    {
+        case LogLevel::TRACE:
+            if (logger.trace())
+                logger.trace(msg);
+            break;
+        case LogLevel::DEBUG:
+            if (logger.debug())
+                logger.debug(msg);
+            break;
+        case LogLevel::INFORMATION:
+            if (logger.information())
+                logger.information(msg);
+            break;
+        case LogLevel::NOTICE:
+            if (logger.notice())
+                logger.notice(msg);
+            break;
+        case LogLevel::WARNING:
+            if (logger.warning())
+                logger.warning(msg);
+            break;
+        case LogLevel::ERROR:
+            if (logger.error())
+                logger.error(msg);
+            break;
+        case LogLevel::CRITICAL:
+            if (logger.critical())
+                logger.critical(msg);
+            break;
+        case LogLevel::FATAL:
+            if (logger.fatal())
+                logger.fatal(msg);
+            break;
+    }
+}
+
+}

programs/odbc-bridge/CMakeLists.txt

@@ -24,6 +24,7 @@ add_executable(clickhouse-odbc-bridge ${CLICKHOUSE_ODBC_BRIDGE_SOURCES})
 target_link_libraries(clickhouse-odbc-bridge PRIVATE
     daemon
     dbms
+    bridge
     clickhouse_parsers
     Poco::Data
     nanodbc

programs/odbc-bridge/HandlerFactory.cpp

@@ -8,7 +8,7 @@
 namespace DB
 {
 
-std::unique_ptr<HTTPRequestHandler> HandlerFactory::createRequestHandler(const HTTPServerRequest & request)
+std::unique_ptr<HTTPRequestHandler> ODBCBridgeHandlerFactory::createRequestHandler(const HTTPServerRequest & request)
 {
     Poco::URI uri{request.getURI()};
     LOG_TRACE(log, "Request URI: {}", uri.toString());

programs/odbc-bridge/HandlerFactory.h

@@ -14,10 +14,10 @@ namespace DB
 /** Factory for '/ping', '/', '/columns_info', '/identifier_quote', '/schema_allowed' handlers.
   * Also stores Session pools for ODBC connections
   */
-class HandlerFactory : public HTTPRequestHandlerFactory
+class ODBCBridgeHandlerFactory : public HTTPRequestHandlerFactory
 {
 public:
-    HandlerFactory(const std::string & name_, size_t keep_alive_timeout_, Context & context_)
+    ODBCBridgeHandlerFactory(const std::string & name_, size_t keep_alive_timeout_, Context & context_)
         : log(&Poco::Logger::get(name_)), name(name_), keep_alive_timeout(keep_alive_timeout_), context(context_)
     {
     }
@@ -30,4 +30,5 @@ private:
     size_t keep_alive_timeout;
     Context & context;
 };
+
 }

programs/odbc-bridge/ODBCBridge.cpp

@@ -1,232 +1,4 @@
 #include "ODBCBridge.h"
-#include "HandlerFactory.h"
-
-#include <string>
-#include <errno.h>
-#include <IO/ReadHelpers.h>
-#include <boost/program_options.hpp>
-#include <Poco/Net/NetException.h>
-#include <Poco/String.h>
-#include <Poco/Util/HelpFormatter.h>
-#include <Common/Exception.h>
-#include <Common/StringUtils/StringUtils.h>
-#include <Common/config.h>
-#include <Formats/registerFormats.h>
-#include <common/logger_useful.h>
-#include <ext/scope_guard.h>
-#include <ext/range.h>
-#include <Common/SensitiveDataMasker.h>
-#include <Server/HTTP/HTTPServer.h>
-
-
-namespace DB
-{
-namespace ErrorCodes
-{
-    extern const int ARGUMENT_OUT_OF_BOUND;
-}
-
-namespace
-{
-    Poco::Net::SocketAddress makeSocketAddress(const std::string & host, UInt16 port, Poco::Logger * log)
-    {
-        Poco::Net::SocketAddress socket_address;
-        try
-        {
-            socket_address = Poco::Net::SocketAddress(host, port);
-        }
-        catch (const Poco::Net::DNSException & e)
-        {
-            const auto code = e.code();
-            if (code == EAI_FAMILY
-#if defined(EAI_ADDRFAMILY)
-                || code == EAI_ADDRFAMILY
-#endif
-            )
-            {
-                LOG_ERROR(log, "Cannot resolve listen_host ({}), error {}: {}. If it is an IPv6 address and your host has disabled IPv6, then consider to specify IPv4 address to listen in <listen_host> element of configuration file. Example: <listen_host>0.0.0.0</listen_host>", host, e.code(), e.message());
-            }
-
-            throw;
-        }
-        return socket_address;
-    }
-
-    Poco::Net::SocketAddress socketBindListen(Poco::Net::ServerSocket & socket, const std::string & host, UInt16 port, Poco::Logger * log)
-    {
-        auto address = makeSocketAddress(host, port, log);
-#if POCO_VERSION < 0x01080000
-        socket.bind(address, /* reuseAddress = */ true);
-#else
-        socket.bind(address, /* reuseAddress = */ true, /* reusePort = */ false);
-#endif
-
-        socket.listen(/* backlog = */ 64);
-
-        return address;
-    }
-}
-
-void ODBCBridge::handleHelp(const std::string &, const std::string &)
-{
-    Poco::Util::HelpFormatter help_formatter(options());
-    help_formatter.setCommand(commandName());
-    help_formatter.setHeader("HTTP-proxy for odbc requests");
-    help_formatter.setUsage("--http-port <port>");
-    help_formatter.format(std::cerr);
-
-    stopOptionsProcessing();
-}
-
-
-void ODBCBridge::defineOptions(Poco::Util::OptionSet & options)
-{
-    options.addOption(Poco::Util::Option("http-port", "", "port to listen").argument("http-port", true).binding("http-port"));
-    options.addOption(
-        Poco::Util::Option("listen-host", "", "hostname or address to listen, default 127.0.0.1").argument("listen-host").binding("listen-host"));
-    options.addOption(
-        Poco::Util::Option("http-timeout", "", "http timeout for socket, default 1800").argument("http-timeout").binding("http-timeout"));
-
-    options.addOption(Poco::Util::Option("max-server-connections", "", "max connections to server, default 1024")
-                          .argument("max-server-connections")
-                          .binding("max-server-connections"));
-    options.addOption(Poco::Util::Option("keep-alive-timeout", "", "keepalive timeout, default 10")
-                          .argument("keep-alive-timeout")
-                          .binding("keep-alive-timeout"));
-
-    options.addOption(Poco::Util::Option("log-level", "", "sets log level, default info").argument("log-level").binding("logger.level"));
-
-    options.addOption(
-        Poco::Util::Option("log-path", "", "log path for all logs, default console").argument("log-path").binding("logger.log"));
-
-    options.addOption(Poco::Util::Option("err-log-path", "", "err log path for all logs, default no")
-                          .argument("err-log-path")
-                          .binding("logger.errorlog"));
-
-    options.addOption(Poco::Util::Option("stdout-path", "", "stdout log path, default console")
-                          .argument("stdout-path")
-                          .binding("logger.stdout"));
-
-    options.addOption(Poco::Util::Option("stderr-path", "", "stderr log path, default console")
-                          .argument("stderr-path")
-                          .binding("logger.stderr"));
-
-    using Me = std::decay_t<decltype(*this)>;
-    options.addOption(Poco::Util::Option("help", "", "produce this help message")
-                          .binding("help")
-                          .callback(Poco::Util::OptionCallback<Me>(this, &Me::handleHelp)));
-
-    ServerApplication::defineOptions(options); // NOLINT Don't need complex BaseDaemon's .xml config
-}
-
-void ODBCBridge::initialize(Application & self)
-{
-    BaseDaemon::closeFDs();
-    is_help = config().has("help");
-
-    if (is_help)
-        return;
-
-    config().setString("logger", "ODBCBridge");
-
-    /// Redirect stdout, stderr to specified files.
-    /// Some libraries and sanitizers write to stderr in case of errors.
-    const auto stdout_path = config().getString("logger.stdout", "");
-    if (!stdout_path.empty())
-    {
-        if (!freopen(stdout_path.c_str(), "a+", stdout))
-            throw Poco::OpenFileException("Cannot attach stdout to " + stdout_path);
-
-        /// Disable buffering for stdout.
-        setbuf(stdout, nullptr);
-    }
-    const auto stderr_path = config().getString("logger.stderr", "");
-    if (!stderr_path.empty())
-    {
-        if (!freopen(stderr_path.c_str(), "a+", stderr))
-            throw Poco::OpenFileException("Cannot attach stderr to " + stderr_path);
-
-        /// Disable buffering for stderr.
-        setbuf(stderr, nullptr);
-    }
-
-    buildLoggers(config(), logger(), self.commandName());
-
-    BaseDaemon::logRevision();
-
-    log = &logger();
-    hostname = config().getString("listen-host", "127.0.0.1");
-    port = config().getUInt("http-port");
-    if (port > 0xFFFF)
-        throw Exception("Out of range 'http-port': " + std::to_string(port), ErrorCodes::ARGUMENT_OUT_OF_BOUND);
-
-    http_timeout = config().getUInt("http-timeout", DEFAULT_HTTP_READ_BUFFER_TIMEOUT);
-    max_server_connections = config().getUInt("max-server-connections", 1024);
-    keep_alive_timeout = config().getUInt("keep-alive-timeout", 10);
-
-    initializeTerminationAndSignalProcessing();
-
-    ServerApplication::initialize(self); // NOLINT
-}
-
-void ODBCBridge::uninitialize()
-{
-    BaseDaemon::uninitialize();
-}
-
-int ODBCBridge::main(const std::vector<std::string> & /*args*/)
-{
-    if (is_help)
-        return Application::EXIT_OK;
-
-    registerFormats();
-
-    LOG_INFO(log, "Starting up");
-    Poco::Net::ServerSocket socket;
-    auto address = socketBindListen(socket, hostname, port, log);
-    socket.setReceiveTimeout(http_timeout);
-    socket.setSendTimeout(http_timeout);
-    Poco::ThreadPool server_pool(3, max_server_connections);
-    Poco::Net::HTTPServerParams::Ptr http_params = new Poco::Net::HTTPServerParams;
-    http_params->setTimeout(http_timeout);
-    http_params->setKeepAliveTimeout(keep_alive_timeout);
-
-    auto shared_context = Context::createShared();
-    Context context(Context::createGlobal(shared_context.get()));
-    context.makeGlobalContext();
-
-    if (config().has("query_masking_rules"))
-    {
-        SensitiveDataMasker::setInstance(std::make_unique<SensitiveDataMasker>(config(), "query_masking_rules"));
-    }
-
-    auto server = HTTPServer(
-        context,
-        std::make_shared<HandlerFactory>("ODBCRequestHandlerFactory-factory", keep_alive_timeout, context),
-        server_pool,
-        socket,
-        http_params);
-    server.start();
-
-    LOG_INFO(log, "Listening http://{}", address.toString());
-
-    SCOPE_EXIT({
-        LOG_DEBUG(log, "Received termination signal.");
-        LOG_DEBUG(log, "Waiting for current connections to close.");
-        server.stop();
-        for (size_t count : ext::range(1, 6))
-        {
-            if (server.currentConnections() == 0)
-                break;
-            LOG_DEBUG(log, "Waiting for {} connections, try {}", server.currentConnections(), count);
-            std::this_thread::sleep_for(std::chrono::milliseconds(1000));
-        }
-    });
-
-    waitForTerminationRequest();
-    return Application::EXIT_OK;
-}
-}
 
 #pragma GCC diagnostic ignored "-Wmissing-declarations"
 int mainEntryClickHouseODBCBridge(int argc, char ** argv)

programs/odbc-bridge/ODBCBridge.h

@@ -2,39 +2,26 @@
 
 #include <Interpreters/Context.h>
 #include <Poco/Logger.h>
-#include <daemon/BaseDaemon.h>
+#include <bridge/IBridge.h>
+#include "HandlerFactory.h"
+
 
 
 namespace DB
 {
-/** Class represents clickhouse-odbc-bridge server, which listen
-  * incoming HTTP POST and GET requests on specified port and host.
-  * Has two handlers '/' for all incoming POST requests to ODBC driver
-  * and /ping for GET request about service status
-  */
-class ODBCBridge : public BaseDaemon
+
+class ODBCBridge : public IBridge
 {
-public:
-    void defineOptions(Poco::Util::OptionSet & options) override;
 
 protected:
-    void initialize(Application & self) override;
+    const std::string bridgeName() const override
+    {
+        return "ODBCBridge";
+    }
 
-    void uninitialize() override;
-
-    int main(const std::vector<std::string> & args) override;
-
-private:
-    void handleHelp(const std::string &, const std::string &);
-
-    bool is_help;
-    std::string hostname;
-    size_t port;
-    size_t http_timeout;
-    std::string log_level;
-    size_t max_server_connections;
-    size_t keep_alive_timeout;
-
-    Poco::Logger * log;
+    HandlerFactoryPtr getHandlerFactoryPtr(Context & context) const override
+    {
+        return std::make_shared<ODBCBridgeHandlerFactory>("ODBCRequestHandlerFactory-factory", keep_alive_timeout, context);
+    }
 };
 }

src/Bridge/IBridgeHelper.cpp

@@ -0,0 +1,132 @@
+#include "IBridgeHelper.h"
+
+#include <IO/ReadWriteBufferFromHTTP.h>
+#include <IO/ReadHelpers.h>
+#include <Poco/Net/HTTPRequest.h>
+#include <Poco/Path.h>
+#include <Poco/URI.h>
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+    extern const int EXTERNAL_SERVER_IS_NOT_RESPONDING;
+}
+
+
+Poco::URI IBridgeHelper::getMainURI() const
+{
+    auto uri = createBaseURI();
+    uri.setPath(MAIN_HANDLER);
+    return uri;
+}
+
+
+Poco::URI IBridgeHelper::getPingURI() const
+{
+    auto uri = createBaseURI();
+    uri.setPath(PING_HANDLER);
+    return uri;
+}
+
+
+bool IBridgeHelper::checkBridgeIsRunning() const
+{
+    try
+    {
+        ReadWriteBufferFromHTTP buf(
+            getPingURI(), Poco::Net::HTTPRequest::HTTP_GET, {}, ConnectionTimeouts::getHTTPTimeouts(getContext()));
+        return checkString(PING_OK_ANSWER, buf);
+    }
+    catch (...)
+    {
+        return false;
+    }
+}
+
+
+void IBridgeHelper::startBridgeSync() const
+{
+    if (!checkBridgeIsRunning())
+    {
+        LOG_TRACE(getLog(), "{} is not running, will try to start it", serviceAlias());
+        startBridge(startBridgeCommand());
+        bool started = false;
+
+        uint64_t milliseconds_to_wait = 10; /// Exponential backoff
+        uint64_t counter = 0;
+
+        while (milliseconds_to_wait < 10000)
+        {
+            ++counter;
+            LOG_TRACE(getLog(), "Checking {} is running, try {}", serviceAlias(), counter);
+
+            if (checkBridgeIsRunning())
+            {
+                started = true;
+                break;
+            }
+
+            std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds_to_wait));
+            milliseconds_to_wait *= 2;
+        }
+
+        if (!started)
+            throw Exception("BridgeHelper: " + serviceAlias() + " is not responding",
+                ErrorCodes::EXTERNAL_SERVER_IS_NOT_RESPONDING);
+    }
+}
+
+
+std::unique_ptr<ShellCommand> IBridgeHelper::startBridgeCommand() const
+{
+    if (startBridgeManually())
+        throw Exception(serviceAlias() + " is not running. Please, start it manually", ErrorCodes::EXTERNAL_SERVER_IS_NOT_RESPONDING);
+
+    const auto & config = getConfig();
+    /// Path to executable folder
+    Poco::Path path{config.getString("application.dir", "/usr/bin")};
+
+    std::vector<std::string> cmd_args;
+    path.setFileName(serviceFileName());
+
+    cmd_args.push_back("--http-port");
+    cmd_args.push_back(std::to_string(config.getUInt(configPrefix() + ".port", getDefaultPort())));
+    cmd_args.push_back("--listen-host");
+    cmd_args.push_back(config.getString(configPrefix() + ".listen_host", DEFAULT_HOST));
+    cmd_args.push_back("--http-timeout");
+    cmd_args.push_back(std::to_string(getHTTPTimeout().totalMicroseconds()));
+    if (config.has("logger." + configPrefix() + "_log"))
+    {
+        cmd_args.push_back("--log-path");
+        cmd_args.push_back(config.getString("logger." + configPrefix() + "_log"));
+    }
+    if (config.has("logger." + configPrefix() + "_errlog"))
+    {
+        cmd_args.push_back("--err-log-path");
+        cmd_args.push_back(config.getString("logger." + configPrefix() + "_errlog"));
+    }
+    if (config.has("logger." + configPrefix() + "_stdout"))
+    {
+        cmd_args.push_back("--stdout-path");
+        cmd_args.push_back(config.getString("logger." + configPrefix() + "_stdout"));
+    }
+    if (config.has("logger." + configPrefix() + "_stderr"))
+    {
+        cmd_args.push_back("--stderr-path");
+        cmd_args.push_back(config.getString("logger." + configPrefix() + "_stderr"));
+    }
+    if (config.has("logger." + configPrefix() + "_level"))
+    {
+        cmd_args.push_back("--log-level");
+        cmd_args.push_back(config.getString("logger." + configPrefix() + "_level"));
+    }
+
+    LOG_TRACE(getLog(), "Starting {}", serviceAlias());
+
+    return ShellCommand::executeDirect(path.toString(), cmd_args, ShellCommandDestructorStrategy(true));
+}
+
+}

src/Bridge/IBridgeHelper.h

@@ -0,0 +1,70 @@
+#pragma once
+
+#include <Interpreters/Context.h>
+#include <Poco/Logger.h>
+#include <Poco/Util/AbstractConfiguration.h>
+#include <Poco/Net/HTTPRequest.h>
+#include <Common/ShellCommand.h>
+#include <IO/ConnectionTimeoutsContext.h>
+#include <common/logger_useful.h>
+
+
+namespace DB
+{
+
+/// Common base class for XDBC and Library bridge helpers.
+/// Contains helper methods to check/start bridge sync.
+class IBridgeHelper
+{
+
+public:
+    static constexpr inline auto DEFAULT_HOST = "127.0.0.1";
+    static constexpr inline auto PING_HANDLER = "/ping";
+    static constexpr inline auto MAIN_HANDLER = "/";
+    static constexpr inline auto DEFAULT_FORMAT = "RowBinary";
+    static constexpr inline auto PING_OK_ANSWER = "Ok.";
+
+    static const inline std::string PING_METHOD = Poco::Net::HTTPRequest::HTTP_GET;
+    static const inline std::string MAIN_METHOD = Poco::Net::HTTPRequest::HTTP_POST;
+
+    virtual ~IBridgeHelper() = default;
+
+    void startBridgeSync() const;
+
+    Poco::URI getMainURI() const;
+
+    Poco::URI getPingURI() const;
+
+
+protected:
+    /// clickhouse-odbc-bridge, clickhouse-library-bridge
+    virtual const String serviceAlias() const = 0;
+
+    virtual const String serviceFileName() const = 0;
+
+    virtual size_t getDefaultPort() const = 0;
+
+    virtual bool startBridgeManually() const = 0;
+
+    virtual void startBridge(std::unique_ptr<ShellCommand> cmd) const = 0;
+
+    virtual const String configPrefix() const = 0;
+
+    virtual const Context & getContext() const = 0;
+
+    virtual const Poco::Util::AbstractConfiguration & getConfig() const = 0;
+
+    virtual Poco::Logger * getLog() const = 0;
+
+    virtual const Poco::Timespan & getHTTPTimeout() const = 0;
+
+    virtual Poco::URI createBaseURI() const = 0;
+
+
+private:
+    bool checkBridgeIsRunning() const;
+
+    std::unique_ptr<ShellCommand> startBridgeCommand() const;
+};
+
+}

src/Bridge/LibraryBridgeHelper.cpp

@@ -0,0 +1,183 @@
+#include "LibraryBridgeHelper.h"
+
+#include <IO/ReadHelpers.h>
+#include <DataStreams/OneBlockInputStream.h>
+#include <DataStreams/OwningBlockInputStream.h>
+#include <Dictionaries/DictionarySourceHelpers.h>
+#include <Processors/Formats/InputStreamFromInputFormat.h>
+#include <IO/WriteBufferFromOStream.h>
+#include <IO/WriteBufferFromString.h>
+#include <Formats/FormatFactory.h>
+#include <Poco/Path.h>
+#include <Poco/Util/AbstractConfiguration.h>
+#include <Common/ShellCommand.h>
+#include <common/logger_useful.h>
+#include <ext/range.h>
+#include <Core/Field.h>
+#include <Common/escapeForFileName.h>
+
+
+namespace DB
+{
+
+LibraryBridgeHelper::LibraryBridgeHelper(
+        const Context & context_,
+        const Block & sample_block_,
+        const Field & dictionary_id_)
+    : log(&Poco::Logger::get("LibraryBridgeHelper"))
+    , context(context_)
+    , sample_block(sample_block_)
+    , config(context.getConfigRef())
+    , http_timeout(context.getSettingsRef().http_receive_timeout.value.totalSeconds())
+    , dictionary_id(dictionary_id_)
+{
+    bridge_port = config.getUInt("library_bridge.port", DEFAULT_PORT);
+    bridge_host = config.getString("library_bridge.host", DEFAULT_HOST);
+}
+
+
+Poco::URI LibraryBridgeHelper::createRequestURI(const String & method) const
+{
+    auto uri = getMainURI();
+    uri.addQueryParameter("dictionary_id", toString(dictionary_id));
+    uri.addQueryParameter("method", method);
+    return uri;
+}
+
+
+Poco::URI LibraryBridgeHelper::createBaseURI() const
+{
+    Poco::URI uri;
+    uri.setHost(bridge_host);
+    uri.setPort(bridge_port);
+    uri.setScheme("http");
+    return uri;
+}
+
+
+void LibraryBridgeHelper::startBridge(std::unique_ptr<ShellCommand> cmd) const
+{
+    context.addBridgeCommand(std::move(cmd));
+}
+
+
+bool LibraryBridgeHelper::initLibrary(const std::string & library_path, const std::string library_settings, const std::string attributes_names)
+{
+    startBridgeSync();
+    auto uri = createRequestURI(LIB_NEW_METHOD);
+
+    /// Sample block must contain null values
+    WriteBufferFromOwnString out;
+    auto output_stream = context.getOutputStream(LibraryBridgeHelper::DEFAULT_FORMAT, out, sample_block);
+    formatBlock(output_stream, sample_block);
+    auto block_string = out.str();
+
+    auto out_stream_callback = [library_path, library_settings, attributes_names, block_string, this](std::ostream & os)
+    {
+        os << "library_path=" << escapeForFileName(library_path) << "&";
+        os << "library_settings=" << escapeForFileName(library_settings) << "&";
+        os << "attributes_names=" << escapeForFileName(attributes_names) << "&";
+        os << "sample_block=" << escapeForFileName(sample_block.getNamesAndTypesList().toString()) << "&";
+        os << "null_values=" << escapeForFileName(block_string);
+    };
+    return executeRequest(uri, out_stream_callback);
+}
+
+
+bool LibraryBridgeHelper::cloneLibrary(const Field & other_dictionary_id)
+{
+    startBridgeSync();
+    auto uri = createRequestURI(LIB_CLONE_METHOD);
+    uri.addQueryParameter("from_dictionary_id", toString(other_dictionary_id));
+    return executeRequest(uri);
+}
+
+
+bool LibraryBridgeHelper::removeLibrary()
+{
+    startBridgeSync();
+    auto uri = createRequestURI(LIB_DELETE_METHOD);
+    return executeRequest(uri);
+}
+
+
+bool LibraryBridgeHelper::isModified()
+{
+    startBridgeSync();
+    auto uri = createRequestURI(IS_MODIFIED_METHOD);
+    return executeRequest(uri);
+}
+
+
+bool LibraryBridgeHelper::supportsSelectiveLoad()
+{
+    startBridgeSync();
+    auto uri = createRequestURI(SUPPORTS_SELECTIVE_LOAD_METHOD);
+    return executeRequest(uri);
+}
+
+
+BlockInputStreamPtr LibraryBridgeHelper::loadAll()
+{
+    startBridgeSync();
+    auto uri = createRequestURI(LOAD_ALL_METHOD);
+    return loadBase(uri);
+}
+
+
+BlockInputStreamPtr LibraryBridgeHelper::loadIds(const std::string ids_string)
+{
+    startBridgeSync();
+    auto uri = createRequestURI(LOAD_IDS_METHOD);
+    return loadBase(uri, [ids_string](std::ostream & os) { os << "ids=" << ids_string; });
+}
+
+
+BlockInputStreamPtr LibraryBridgeHelper::loadKeys(const Block & requested_block)
+{
+    startBridgeSync();
+    auto uri = createRequestURI(LOAD_KEYS_METHOD);
+    /// Sample block to parse block from callback
+    uri.addQueryParameter("requested_block_sample", requested_block.getNamesAndTypesList().toString());
+    ReadWriteBufferFromHTTP::OutStreamCallback out_stream_callback = [requested_block, this](std::ostream & os)
+    {
+        WriteBufferFromOStream out_buffer(os);
+        auto output_stream = context.getOutputStream(
+                LibraryBridgeHelper::DEFAULT_FORMAT, out_buffer, sample_block);
+        formatBlock(output_stream, requested_block);
+    };
+    return loadBase(uri, out_stream_callback);
+}
+
+
+bool LibraryBridgeHelper::executeRequest(const Poco::URI & uri, ReadWriteBufferFromHTTP::OutStreamCallback out_stream_callback)
+{
+    ReadWriteBufferFromHTTP buf(
+        uri,
+        Poco::Net::HTTPRequest::HTTP_POST,
+        std::move(out_stream_callback),
+        ConnectionTimeouts::getHTTPTimeouts(context));
+
+    bool res;
+    readBoolText(res, buf);
+    return res;
+}
+
+
+BlockInputStreamPtr LibraryBridgeHelper::loadBase(const Poco::URI & uri, ReadWriteBufferFromHTTP::OutStreamCallback out_stream_callback)
+{
+    auto read_buf_ptr = std::make_unique<ReadWriteBufferFromHTTP>(
+        uri,
+        Poco::Net::HTTPRequest::HTTP_POST,
+        std::move(out_stream_callback),
+        ConnectionTimeouts::getHTTPTimeouts(context),
+        0,
+        Poco::Net::HTTPBasicCredentials{},
+        DBMS_DEFAULT_BUFFER_SIZE,
+        ReadWriteBufferFromHTTP::HTTPHeaderEntries{});
+
+    auto input_stream = context.getInputFormat(LibraryBridgeHelper::DEFAULT_FORMAT, *read_buf_ptr, sample_block, DEFAULT_BLOCK_SIZE);
+    return std::make_shared<OwningBlockInputStream<ReadWriteBufferFromHTTP>>(input_stream, std::move(read_buf_ptr));
+}
+
+}

src/Bridge/LibraryBridgeHelper.h

@@ -0,0 +1,88 @@
+#pragma once
+
+#include <Interpreters/Context.h>
+#include <IO/ReadWriteBufferFromHTTP.h>
+#include <Poco/Logger.h>
+#include <Poco/Net/HTTPRequest.h>
+#include <Poco/URI.h>
+#include <Bridge/IBridgeHelper.h>
+
+
+namespace DB
+{
+
+class LibraryBridgeHelper : public IBridgeHelper
+{
+
+public:
+    static constexpr inline size_t DEFAULT_PORT = 9012;
+
+    LibraryBridgeHelper(const Context & context_, const Block & sample_block, const Field & dictionary_id_);
+
+    bool initLibrary(const std::string & library_path, const std::string library_settings, const std::string attributes_names);
+
+    bool cloneLibrary(const Field & other_dictionary_id);
+
+    bool removeLibrary();
+
+    bool isModified();
+
+    bool supportsSelectiveLoad();
+
+    BlockInputStreamPtr loadAll();
+
+    BlockInputStreamPtr loadIds(const std::string ids_string);
+
+    BlockInputStreamPtr loadKeys(const Block & requested_block);
+
+    BlockInputStreamPtr loadBase(const Poco::URI & uri, ReadWriteBufferFromHTTP::OutStreamCallback out_stream_callback = {});
+
+    bool executeRequest(const Poco::URI & uri, ReadWriteBufferFromHTTP::OutStreamCallback out_stream_callback = {});
+
+
+protected:
+    void startBridge(std::unique_ptr<ShellCommand> cmd) const override;
+
+    const String serviceAlias() const override { return "clickhouse-library-bridge"; }
+
+    const String serviceFileName() const override { return serviceAlias(); }
+
+    size_t getDefaultPort() const override { return DEFAULT_PORT; }
+
+    bool startBridgeManually() const override { return false; }
+
+    const String configPrefix() const override { return "library_bridge"; }
+
+    const Context & getContext() const override { return context; }
+
+    const Poco::Util::AbstractConfiguration & getConfig() const override { return config; }
+
+    Poco::Logger * getLog() const override { return log; }
+
+    const Poco::Timespan & getHTTPTimeout() const override { return http_timeout; }
+
+    Poco::URI createBaseURI() const override;
+
+private:
+    static constexpr inline auto LIB_NEW_METHOD = "libNew";
+    static constexpr inline auto LIB_CLONE_METHOD = "libClone";
+    static constexpr inline auto LIB_DELETE_METHOD = "libDelete";
+    static constexpr inline auto LOAD_ALL_METHOD = "loadAll";
+    static constexpr inline auto LOAD_IDS_METHOD = "loadIds";
+    static constexpr inline auto LOAD_KEYS_METHOD = "loadKeys";
+    static constexpr inline auto IS_MODIFIED_METHOD = "isModified";
+    static constexpr inline auto SUPPORTS_SELECTIVE_LOAD_METHOD = "supportsSelectiveLoad";
+
+    Poco::URI createRequestURI(const String & method) const;
+
+    Poco::Logger * log;
+    const Context & context;
+    const Block sample_block;
+    const Poco::Util::AbstractConfiguration & config;
+    const Poco::Timespan http_timeout;
+
+    Field dictionary_id;
+    std::string bridge_host;
+    size_t bridge_port;
+};
+}

src/Bridge/XDBCBridgeHelper.h

@@ -0,0 +1,266 @@
+#pragma once
+
+#include <IO/ReadHelpers.h>
+#include <IO/ReadWriteBufferFromHTTP.h>
+#include <Interpreters/Context.h>
+#include <Access/AccessType.h>
+#include <Parsers/IdentifierQuotingStyle.h>
+#include <Poco/File.h>
+#include <Poco/Logger.h>
+#include <Poco/Net/HTTPRequest.h>
+#include <Poco/Path.h>
+#include <Poco/URI.h>
+#include <Poco/Util/AbstractConfiguration.h>
+#include <Common/ShellCommand.h>
+#include <IO/ConnectionTimeoutsContext.h>
+#include <common/logger_useful.h>
+#include <ext/range.h>
+#include <Bridge/IBridgeHelper.h>
+
+#if !defined(ARCADIA_BUILD)
+#    include <Common/config.h>
+#endif
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
+}
+
+/// Class for Helpers for XDBC-bridges, provide utility methods, not main request.
+class IXDBCBridgeHelper : public IBridgeHelper
+{
+
+public:
+    virtual std::vector<std::pair<std::string, std::string>> getURLParams(const std::string & cols, UInt64 max_block_size) const = 0;
+
+    virtual Poco::URI getColumnsInfoURI() const = 0;
+
+    virtual IdentifierQuotingStyle getIdentifierQuotingStyle() = 0;
+
+    virtual bool isSchemaAllowed() = 0;
+
+    virtual const String getName() const = 0;
+};
+
+using BridgeHelperPtr = std::shared_ptr<IXDBCBridgeHelper>;
+
+
+template <typename BridgeHelperMixin>
+class XDBCBridgeHelper : public IXDBCBridgeHelper
+{
+
+public:
+    static constexpr inline auto DEFAULT_PORT = BridgeHelperMixin::DEFAULT_PORT;
+    static constexpr inline auto COL_INFO_HANDLER = "/columns_info";
+    static constexpr inline auto IDENTIFIER_QUOTE_HANDLER = "/identifier_quote";
+    static constexpr inline auto SCHEMA_ALLOWED_HANDLER = "/schema_allowed";
+
+    XDBCBridgeHelper(
+            const Context & global_context_,
+            const Poco::Timespan & http_timeout_,
+            const std::string & connection_string_)
+    : log(&Poco::Logger::get(BridgeHelperMixin::getName() + "BridgeHelper"))
+    , connection_string(connection_string_)
+    , http_timeout(http_timeout_)
+    , context(global_context_)
+    , config(context.getConfigRef())
+{
+    bridge_host = config.getString(BridgeHelperMixin::configPrefix() + ".host", DEFAULT_HOST);
+    bridge_port = config.getUInt(BridgeHelperMixin::configPrefix() + ".port", DEFAULT_PORT);
+}
+
+
+protected:
+    auto getConnectionString() const { return connection_string; }
+
+    const String getName() const override { return BridgeHelperMixin::getName(); }
+
+    size_t getDefaultPort() const override { return DEFAULT_PORT; }
+
+    const String serviceAlias() const override { return BridgeHelperMixin::serviceAlias(); }
+
+    /// Same for odbc and jdbc
+    const String serviceFileName() const override { return "clickhouse-odbc-bridge"; }
+
+    const String configPrefix() const override { return BridgeHelperMixin::configPrefix(); }
+
+    const Context & getContext() const override { return context; }
+
+    const Poco::Timespan & getHTTPTimeout() const override { return http_timeout; }
+
+    const Poco::Util::AbstractConfiguration & getConfig() const override { return config; }
+
+    Poco::Logger * getLog() const override { return log; }
+
+    bool startBridgeManually() const override { return BridgeHelperMixin::startBridgeManually(); }
+
+    Poco::URI createBaseURI() const override
+    {
+        Poco::URI uri;
+        uri.setHost(bridge_host);
+        uri.setPort(bridge_port);
+        uri.setScheme("http");
+        return uri;
+    }
+
+    void startBridge(std::unique_ptr<ShellCommand> cmd) const override
+    {
+        context.addBridgeCommand(std::move(cmd));
+    }
+
+
+private:
+    using Configuration = Poco::Util::AbstractConfiguration;
+
+    Poco::Logger * log;
+    std::string connection_string;
+    const Poco::Timespan & http_timeout;
+    std::string bridge_host;
+    size_t bridge_port;
+
+    const Context & context;
+    const Configuration & config;
+
+    std::optional<IdentifierQuotingStyle> quote_style;
+    std::optional<bool> is_schema_allowed;
+
+
+protected:
+    using URLParams = std::vector<std::pair<std::string, std::string>>;
+
+    Poco::URI getColumnsInfoURI() const override
+    {
+        auto uri = createBaseURI();
+        uri.setPath(COL_INFO_HANDLER);
+        return uri;
+    }
+
+    URLParams getURLParams(const std::string & cols, UInt64 max_block_size) const override
+    {
+        std::vector<std::pair<std::string, std::string>> result;
+
+        result.emplace_back("connection_string", connection_string); /// already validated
+        result.emplace_back("columns", cols);
+        result.emplace_back("max_block_size", std::to_string(max_block_size));
+
+        return result;
+    }
+
+    bool isSchemaAllowed() override
+    {
+        if (!is_schema_allowed.has_value())
+        {
+            startBridgeSync();
+
+            auto uri = createBaseURI();
+            uri.setPath(SCHEMA_ALLOWED_HANDLER);
+            uri.addQueryParameter("connection_string", getConnectionString());
+
+            ReadWriteBufferFromHTTP buf(
+                uri, Poco::Net::HTTPRequest::HTTP_POST, {}, ConnectionTimeouts::getHTTPTimeouts(context));
+
+            bool res;
+            readBoolText(res, buf);
+            is_schema_allowed = res;
+        }
+
+        return *is_schema_allowed;
+    }
+
+    IdentifierQuotingStyle getIdentifierQuotingStyle() override
+    {
+        if (!quote_style.has_value())
+        {
+            startBridgeSync();
+
+            auto uri = createBaseURI();
+            uri.setPath(IDENTIFIER_QUOTE_HANDLER);
+            uri.addQueryParameter("connection_string", getConnectionString());
+
+            ReadWriteBufferFromHTTP buf(
+                uri, Poco::Net::HTTPRequest::HTTP_POST, {}, ConnectionTimeouts::getHTTPTimeouts(context));
+            std::string character;
+            readStringBinary(character, buf);
+            if (character.length() > 1)
+                throw Exception("Failed to parse quoting style from '" + character + "' for service " + BridgeHelperMixin::serviceAlias(), ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+            else if (character.length() == 0)
+                quote_style = IdentifierQuotingStyle::None;
+            else if (character[0] == '`')
+                quote_style = IdentifierQuotingStyle::Backticks;
+            else if (character[0] == '"')
+                quote_style = IdentifierQuotingStyle::DoubleQuotes;
+            else
+                throw Exception("Can not map quote identifier '" + character + "' to enum value", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+        }
+
+        return *quote_style;
+    }
+};
+
+
+struct JDBCBridgeMixin
+{
+    static constexpr inline auto DEFAULT_PORT = 9019;
+
+    static const String configPrefix()
+    {
+        return "jdbc_bridge";
+    }
+
+    static const String serviceAlias()
+    {
+        return "clickhouse-jdbc-bridge";
+    }
+
+    static const String getName()
+    {
+        return "JDBC";
+    }
+
+    static AccessType getSourceAccessType()
+    {
+        return AccessType::JDBC;
+    }
+
+    static bool startBridgeManually()
+    {
+        return true;
+    }
+};
+
+
+struct ODBCBridgeMixin
+{
+    static constexpr inline auto DEFAULT_PORT = 9018;
+
+    static const String configPrefix()
+    {
+        return "odbc_bridge";
+    }
+
+    static const String serviceAlias()
+    {
+        return "clickhouse-odbc-bridge";
+    }
+
+    static const String getName()
+    {
+        return "ODBC";
+    }
+
+    static AccessType getSourceAccessType()
+    {
+        return AccessType::ODBC;
+    }
+
+    static bool startBridgeManually()
+    {
+        return false;
+    }
+};
+
+}

src/Bridge/ya.make

@@ -0,0 +1,17 @@
+# This file is generated automatically, do not edit. See 'ya.make.in' and use 'utils/generate-ya-make' to regenerate it.
+OWNER(g:clickhouse)
+
+LIBRARY()
+
+PEERDIR(
+    clickhouse/src/Common
+)
+
+
+SRCS(
+    IBridgeHelper.cpp
+    LibraryBridgeHelper.cpp
+
+)
+
+END()

src/Bridge/ya.make.in

@@ -0,0 +1,14 @@
+OWNER(g:clickhouse)
+
+LIBRARY()
+
+PEERDIR(
+    clickhouse/src/Common
+)
+
+
+SRCS(
+<? find . -name '*.cpp' | grep -v -F tests | sed 's/^\.\//    /' | sort ?>
+)
+
+END()

src/CMakeLists.txt

@@ -190,6 +190,7 @@ add_object_library(clickhouse_storages_distributed Storages/Distributed)
 add_object_library(clickhouse_storages_mergetree Storages/MergeTree)
 add_object_library(clickhouse_storages_liveview Storages/LiveView)
 add_object_library(clickhouse_client Client)
+add_object_library(clickhouse_bridge Bridge)
 add_object_library(clickhouse_server Server)
 add_object_library(clickhouse_server_http Server/HTTP)
 add_object_library(clickhouse_formats Formats)

src/Common/ErrorCodes.cpp

@@ -590,7 +590,7 @@ namespace ErrorCodes
 
     void increment(ErrorCode error_code, bool remote, const std::string & message, const FramePointers & trace)
     {
-        if (error_code >= end())
+        if (error_code < 0 || error_code >= end())
         {
             /// For everything outside the range, use END.
             /// (end() is the pointer pass the end, while END is the last value that has an element in values array).

src/Common/XDBCBridgeHelper.h

@@ -1,351 +0,0 @@
-#pragma once
-
-#include <IO/ReadHelpers.h>
-#include <IO/ReadWriteBufferFromHTTP.h>
-#include <Interpreters/Context.h>
-#include <Access/AccessType.h>
-#include <Parsers/IdentifierQuotingStyle.h>
-#include <Poco/File.h>
-#include <Poco/Logger.h>
-#include <Poco/Net/HTTPRequest.h>
-#include <Poco/Path.h>
-#include <Poco/URI.h>
-#include <Poco/Util/AbstractConfiguration.h>
-#include <Common/ShellCommand.h>
-#include <IO/ConnectionTimeoutsContext.h>
-#include <common/logger_useful.h>
-#include <ext/range.h>
-
-#if !defined(ARCADIA_BUILD)
-#    include <Common/config.h>
-#endif
-
-namespace DB
-{
-namespace ErrorCodes
-{
-    extern const int EXTERNAL_SERVER_IS_NOT_RESPONDING;
-    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
-}
-
-/**
- * Class for Helpers for Xdbc-bridges, provide utility methods, not main request
- */
-class IXDBCBridgeHelper
-{
-public:
-    static constexpr inline auto DEFAULT_FORMAT = "RowBinary";
-
-    virtual std::vector<std::pair<std::string, std::string>> getURLParams(const std::string & cols, UInt64 max_block_size) const = 0;
-    virtual void startBridgeSync() const = 0;
-    virtual Poco::URI getMainURI() const = 0;
-    virtual Poco::URI getColumnsInfoURI() const = 0;
-    virtual IdentifierQuotingStyle getIdentifierQuotingStyle() = 0;
-    virtual bool isSchemaAllowed() = 0;
-    virtual String getName() const = 0;
-
-    virtual ~IXDBCBridgeHelper() = default;
-};
-
-using BridgeHelperPtr = std::shared_ptr<IXDBCBridgeHelper>;
-
-template <typename BridgeHelperMixin>
-class XDBCBridgeHelper : public IXDBCBridgeHelper
-{
-private:
-    Poco::Timespan http_timeout;
-
-    std::string connection_string;
-
-    Poco::URI ping_url;
-
-    Poco::Logger * log = &Poco::Logger::get(BridgeHelperMixin::getName() + "BridgeHelper");
-
-    std::optional<IdentifierQuotingStyle> quote_style;
-    std::optional<bool> is_schema_allowed;
-
-protected:
-    auto getConnectionString() const
-    {
-        return connection_string;
-    }
-
-public:
-    using Configuration = Poco::Util::AbstractConfiguration;
-
-    const Context & context;
-    const Configuration & config;
-
-    static constexpr inline auto DEFAULT_HOST = "127.0.0.1";
-    static constexpr inline auto DEFAULT_PORT = BridgeHelperMixin::DEFAULT_PORT;
-    static constexpr inline auto PING_HANDLER = "/ping";
-    static constexpr inline auto MAIN_HANDLER = "/";
-    static constexpr inline auto COL_INFO_HANDLER = "/columns_info";
-    static constexpr inline auto IDENTIFIER_QUOTE_HANDLER = "/identifier_quote";
-    static constexpr inline auto SCHEMA_ALLOWED_HANDLER = "/schema_allowed";
-    static constexpr inline auto PING_OK_ANSWER = "Ok.";
-
-    XDBCBridgeHelper(const Context & global_context_, const Poco::Timespan & http_timeout_, const std::string & connection_string_)
-        : http_timeout(http_timeout_), connection_string(connection_string_), context(global_context_), config(context.getConfigRef())
-    {
-        size_t bridge_port = config.getUInt(BridgeHelperMixin::configPrefix() + ".port", DEFAULT_PORT);
-        std::string bridge_host = config.getString(BridgeHelperMixin::configPrefix() + ".host", DEFAULT_HOST);
-
-        ping_url.setHost(bridge_host);
-        ping_url.setPort(bridge_port);
-        ping_url.setScheme("http");
-        ping_url.setPath(PING_HANDLER);
-    }
-
-    String getName() const override
-    {
-        return BridgeHelperMixin::getName();
-    }
-
-    IdentifierQuotingStyle getIdentifierQuotingStyle() override
-    {
-        if (!quote_style.has_value())
-        {
-            startBridgeSync();
-
-            auto uri = createBaseURI();
-            uri.setPath(IDENTIFIER_QUOTE_HANDLER);
-            uri.addQueryParameter("connection_string", getConnectionString());
-
-            ReadWriteBufferFromHTTP buf(
-                uri, Poco::Net::HTTPRequest::HTTP_POST, {}, ConnectionTimeouts::getHTTPTimeouts(context));
-            std::string character;
-            readStringBinary(character, buf);
-            if (character.length() > 1)
-                throw Exception("Failed to parse quoting style from '" + character + "' for service " + BridgeHelperMixin::serviceAlias(), ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
-            else if (character.length() == 0)
-                quote_style = IdentifierQuotingStyle::None;
-            else if (character[0] == '`')
-                quote_style = IdentifierQuotingStyle::Backticks;
-            else if (character[0] == '"')
-                quote_style = IdentifierQuotingStyle::DoubleQuotes;
-            else
-                throw Exception("Can not map quote identifier '" + character + "' to enum value", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
-        }
-
-        return *quote_style;
-    }
-
-    bool isSchemaAllowed() override
-    {
-        if (!is_schema_allowed.has_value())
-        {
-            startBridgeSync();
-
-            auto uri = createBaseURI();
-            uri.setPath(SCHEMA_ALLOWED_HANDLER);
-            uri.addQueryParameter("connection_string", getConnectionString());
-
-            ReadWriteBufferFromHTTP buf(
-                uri, Poco::Net::HTTPRequest::HTTP_POST, {}, ConnectionTimeouts::getHTTPTimeouts(context));
-
-            bool res;
-            readBoolText(res, buf);
-            is_schema_allowed = res;
-        }
-
-        return *is_schema_allowed;
-    }
-
-    /**
-     * @todo leaky abstraction - used by external API's
-     */
-    std::vector<std::pair<std::string, std::string>> getURLParams(const std::string & cols, UInt64 max_block_size) const override
-    {
-        std::vector<std::pair<std::string, std::string>> result;
-
-        result.emplace_back("connection_string", connection_string); /// already validated
-        result.emplace_back("columns", cols);
-        result.emplace_back("max_block_size", std::to_string(max_block_size));
-
-        return result;
-    }
-
-    /**
-     * Performs spawn of external daemon
-     */
-    void startBridgeSync() const override
-    {
-        if (!checkBridgeIsRunning())
-        {
-            LOG_TRACE(log, "{} is not running, will try to start it", BridgeHelperMixin::serviceAlias());
-            startBridge();
-            bool started = false;
-
-            uint64_t milliseconds_to_wait = 10; /// Exponential backoff
-            uint64_t counter = 0;
-            while (milliseconds_to_wait < 10000)
-            {
-                ++counter;
-                LOG_TRACE(log, "Checking {} is running, try {}", BridgeHelperMixin::serviceAlias(), counter);
-                if (checkBridgeIsRunning())
-                {
-                    started = true;
-                    break;
-                }
-                std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds_to_wait));
-                milliseconds_to_wait *= 2;
-            }
-
-            if (!started)
-                throw Exception(BridgeHelperMixin::getName() + "BridgeHelper: " + BridgeHelperMixin::serviceAlias() + " is not responding",
-                    ErrorCodes::EXTERNAL_SERVER_IS_NOT_RESPONDING);
-        }
-    }
-
-    /**
-     * URI to fetch the data from external service
-     */
-    Poco::URI getMainURI() const override
-    {
-        auto uri = createBaseURI();
-        uri.setPath(MAIN_HANDLER);
-        return uri;
-    }
-
-    /**
-     * URI to retrieve column description from external service
-     */
-    Poco::URI getColumnsInfoURI() const override
-    {
-        auto uri = createBaseURI();
-        uri.setPath(COL_INFO_HANDLER);
-        return uri;
-    }
-
-protected:
-    Poco::URI createBaseURI() const
-    {
-        Poco::URI uri;
-        uri.setHost(ping_url.getHost());
-        uri.setPort(ping_url.getPort());
-        uri.setScheme("http");
-        return uri;
-    }
-
-private:
-    bool checkBridgeIsRunning() const
-    {
-        try
-        {
-            ReadWriteBufferFromHTTP buf(
-                ping_url, Poco::Net::HTTPRequest::HTTP_GET, {}, ConnectionTimeouts::getHTTPTimeouts(context));
-            return checkString(XDBCBridgeHelper::PING_OK_ANSWER, buf);
-        }
-        catch (...)
-        {
-            return false;
-        }
-    }
-
-    /* Contains logic for instantiation of the bridge instance */
-    void startBridge() const
-    {
-        auto cmd = BridgeHelperMixin::startBridge(config, log, http_timeout);
-        context.addXDBCBridgeCommand(std::move(cmd));
-    }
-};
-
-struct JDBCBridgeMixin
-{
-    static constexpr inline auto DEFAULT_PORT = 9019;
-    static const String configPrefix()
-    {
-        return "jdbc_bridge";
-    }
-    static const String serviceAlias()
-    {
-        return "clickhouse-jdbc-bridge";
-    }
-    static const String getName()
-    {
-        return "JDBC";
-    }
-    static AccessType getSourceAccessType()
-    {
-        return AccessType::JDBC;
-    }
-
-    static std::unique_ptr<ShellCommand> startBridge(const Poco::Util::AbstractConfiguration &, const Poco::Logger *, const Poco::Timespan &)
-    {
-        throw Exception("jdbc-bridge is not running. Please, start it manually", ErrorCodes::EXTERNAL_SERVER_IS_NOT_RESPONDING);
-    }
-};
-
-struct ODBCBridgeMixin
-{
-    static constexpr inline auto DEFAULT_PORT = 9018;
-
-    static const String configPrefix()
-    {
-        return "odbc_bridge";
-    }
-    static const String serviceAlias()
-    {
-        return "clickhouse-odbc-bridge";
-    }
-    static const String getName()
-    {
-        return "ODBC";
-    }
-    static AccessType getSourceAccessType()
-    {
-        return AccessType::ODBC;
-    }
-
-    static std::unique_ptr<ShellCommand> startBridge(
-        const Poco::Util::AbstractConfiguration & config, Poco::Logger * log, const Poco::Timespan & http_timeout)
-    {
-        /// Path to executable folder
-        Poco::Path path{config.getString("application.dir", "/usr/bin")};
-
-        std::vector<std::string> cmd_args;
-        path.setFileName("clickhouse-odbc-bridge");
-
-#if !CLICKHOUSE_SPLIT_BINARY
-        cmd_args.push_back("odbc-bridge");
-#endif
-
-        cmd_args.push_back("--http-port");
-        cmd_args.push_back(std::to_string(config.getUInt(configPrefix() + ".port", DEFAULT_PORT)));
-        cmd_args.push_back("--listen-host");
-        cmd_args.push_back(config.getString(configPrefix() + ".listen_host", XDBCBridgeHelper<ODBCBridgeMixin>::DEFAULT_HOST));
-        cmd_args.push_back("--http-timeout");
-        cmd_args.push_back(std::to_string(http_timeout.totalMicroseconds()));
-        if (config.has("logger." + configPrefix() + "_log"))
-        {
-            cmd_args.push_back("--log-path");
-            cmd_args.push_back(config.getString("logger." + configPrefix() + "_log"));
-        }
-        if (config.has("logger." + configPrefix() + "_errlog"))
-        {
-            cmd_args.push_back("--err-log-path");
-            cmd_args.push_back(config.getString("logger." + configPrefix() + "_errlog"));
-        }
-        if (config.has("logger." + configPrefix() + "_stdout"))
-        {
-            cmd_args.push_back("--stdout-path");
-            cmd_args.push_back(config.getString("logger." + configPrefix() + "_stdout"));
-        }
-        if (config.has("logger." + configPrefix() + "_stderr"))
-        {
-            cmd_args.push_back("--stderr-path");
-            cmd_args.push_back(config.getString("logger." + configPrefix() + "_stderr"));
-        }
-        if (config.has("logger." + configPrefix() + "_level"))
-        {
-            cmd_args.push_back("--log-level");
-            cmd_args.push_back(config.getString("logger." + configPrefix() + "_level"));
-        }
-
-        LOG_TRACE(log, "Starting {}", serviceAlias());
-
-        return ShellCommand::executeDirect(path.toString(), cmd_args, ShellCommandDestructorStrategy(true));
-    }
-};
-}

src/Common/formatReadable.cpp

@@ -13,7 +13,10 @@ namespace DB
     }
 }
 
-static void formatReadable(double size, DB::WriteBuffer & out, int precision, const char ** units, size_t units_size, double delimiter)
+// I wanted to make this ALWAYS_INLINE to prevent flappy performance tests,
+// but GCC complains it may not be inlined.
+static void formatReadable(double size, DB::WriteBuffer & out,
+    int precision, const char ** units, size_t units_size, double delimiter)
 {
     size_t i = 0;
     for (; i + 1 < units_size && fabs(size) >= delimiter; ++i)

src/Common/parseRemoteDescription.cpp

@@ -1,6 +1,9 @@
 #include "parseRemoteDescription.h"
 #include <Common/Exception.h>
 #include <IO/WriteHelpers.h>
+#include <IO/ReadHelpers.h>
+#include <common/logger_useful.h>
+
 
 namespace DB
 {
@@ -167,4 +170,27 @@ std::vector<String> parseRemoteDescription(const String & description, size_t l,
     return res;
 }
 
+
+std::vector<std::pair<String, uint16_t>> parseRemoteDescriptionForExternalDatabase(const String & description, size_t max_addresses, UInt16 default_port)
+{
+    auto addresses = parseRemoteDescription(description, 0, description.size(), '|', max_addresses);
+    std::vector<std::pair<String, uint16_t>> result;
+
+    for (const auto & address : addresses)
+    {
+        size_t colon = address.find(':');
+        if (colon == String::npos)
+        {
+            LOG_WARNING(&Poco::Logger::get("ParseRemoteDescription"), "Port is not found for host: {}. Using default port {}", default_port);
+            result.emplace_back(std::make_pair(address, default_port));
+        }
+        else
+        {
+            result.emplace_back(std::make_pair(address.substr(0, colon), DB::parseFromString<UInt16>(address.substr(colon + 1))));
+        }
+    }
+
+    return result;
+}
+
 }

src/Common/parseRemoteDescription.h

@@ -17,4 +17,7 @@ namespace DB
  */
 std::vector<String> parseRemoteDescription(const String & description, size_t l, size_t r, char separator, size_t max_addresses);
 
+/// Parse remote description for external database (MySQL or PostgreSQL).
+std::vector<std::pair<String, uint16_t>> parseRemoteDescriptionForExternalDatabase(const String & description, size_t max_addresses, UInt16 default_port);
+
 }

src/Core/Settings.h

@@ -371,6 +371,7 @@ class IColumn;
     \
     M(UInt64, postgresql_connection_pool_size, 16, "Connection pool size for PostgreSQL table engine and database engine.", 0) \
     M(Int64, postgresql_connection_pool_wait_timeout, -1, "Connection pool push/pop timeout on empty pool for PostgreSQL table engine and database engine. By default it will block on empty pool.", 0) \
+    M(UInt64, glob_expansion_max_elements, 1000, "Maximum number of allowed addresses (For external storages, table functions, etc).", 0) \
     \
     M(Seconds, distributed_replica_error_half_life, DBMS_CONNECTION_POOL_WITH_FAILOVER_DEFAULT_DECREASE_ERROR_PERIOD, "Time period reduces replica error counter by 2 times.", 0) \
     M(UInt64, distributed_replica_error_cap, DBMS_CONNECTION_POOL_WITH_FAILOVER_MAX_ERROR_COUNT, "Max number of errors per replica, prevents piling up an incredible amount of errors if replica was offline for some time and allows it to be reconsidered in a shorter amount of time.", 0) \

src/DataStreams/PostgreSQLBlockInputStream.cpp

@@ -28,7 +28,7 @@ namespace ErrorCodes
 }
 
 PostgreSQLBlockInputStream::PostgreSQLBlockInputStream(
-    PostgreSQLConnectionHolderPtr connection_,
+    postgres::ConnectionHolderPtr connection_,
     const std::string & query_str_,
     const Block & sample_block,
     const UInt64 max_block_size_)
@@ -120,8 +120,15 @@ void PostgreSQLBlockInputStream::insertValue(IColumn & column, std::string_view
     switch (type)
     {
         case ValueType::vtUInt8:
+        {
+            if (value == "t")
+                assert_cast<ColumnUInt8 &>(column).insertValue(1);
+            else if (value == "f")
+                assert_cast<ColumnUInt8 &>(column).insertValue(0);
+            else
                 assert_cast<ColumnUInt8 &>(column).insertValue(pqxx::from_string<uint16_t>(value));
             break;
+        }
         case ValueType::vtUInt16:
             assert_cast<ColumnUInt16 &>(column).insertValue(pqxx::from_string<uint16_t>(value));
             break;

src/DataStreams/PostgreSQLBlockInputStream.h

@@ -19,7 +19,7 @@ class PostgreSQLBlockInputStream : public IBlockInputStream
 {
 public:
     PostgreSQLBlockInputStream(
-        PostgreSQLConnectionHolderPtr connection_,
+        postgres::ConnectionHolderPtr connection_,
         const std::string & query_str,
         const Block & sample_block,
         const UInt64 max_block_size_);
@@ -46,7 +46,7 @@ private:
     const UInt64 max_block_size;
     ExternalResultDescription description;
 
-    PostgreSQLConnectionHolderPtr connection;
+    postgres::ConnectionHolderPtr connection;
     std::unique_ptr<pqxx::read_transaction> tx;
     std::unique_ptr<pqxx::stream_from> stream;
 

src/Databases/DatabaseFactory.cpp

@@ -30,6 +30,7 @@
 #endif
 
 #if USE_MYSQL || USE_LIBPQXX
+#include <Common/parseRemoteDescription.h>
 #include <Interpreters/evaluateConstantExpression.h>
 #include <Common/parseAddress.h>
 #endif
@@ -133,19 +134,20 @@ DatabasePtr DatabaseFactory::getImpl(const ASTCreateQuery & create, const String
         ASTs & arguments = engine->arguments->children;
         arguments[1] = evaluateConstantExpressionOrIdentifierAsLiteral(arguments[1], context);
 
-        const auto & host_name_and_port = safeGetLiteralValue<String>(arguments[0], engine_name);
+        const auto & host_port = safeGetLiteralValue<String>(arguments[0], engine_name);
         const auto & mysql_database_name = safeGetLiteralValue<String>(arguments[1], engine_name);
         const auto & mysql_user_name = safeGetLiteralValue<String>(arguments[2], engine_name);
         const auto & mysql_user_password = safeGetLiteralValue<String>(arguments[3], engine_name);
 
         try
         {
-            const auto & [remote_host_name, remote_port] = parseAddress(host_name_and_port, 3306);
-            auto mysql_pool = mysqlxx::Pool(mysql_database_name, remote_host_name, mysql_user_name, mysql_user_password, remote_port);
-
             if (engine_name == "MySQL")
             {
                 auto mysql_database_settings = std::make_unique<ConnectionMySQLSettings>();
+                /// Split into replicas if needed.
+                size_t max_addresses = context.getSettingsRef().glob_expansion_max_elements;
+                auto addresses = parseRemoteDescriptionForExternalDatabase(host_port, max_addresses, 3306);
+                auto mysql_pool = mysqlxx::PoolWithFailover(mysql_database_name, addresses, mysql_user_name, mysql_user_password);
 
                 mysql_database_settings->loadFromQueryContext(context);
                 mysql_database_settings->loadFromQuery(*engine_define); /// higher priority
@@ -154,7 +156,10 @@ DatabasePtr DatabaseFactory::getImpl(const ASTCreateQuery & create, const String
                     context, database_name, metadata_path, engine_define, mysql_database_name, std::move(mysql_database_settings), std::move(mysql_pool));
             }
 
+            const auto & [remote_host_name, remote_port] = parseAddress(host_port, 3306);
             MySQLClient client(remote_host_name, remote_port, mysql_user_name, mysql_user_password);
+            auto mysql_pool = mysqlxx::Pool(mysql_database_name, remote_host_name, mysql_user_name, mysql_user_password);
+
 
             auto materialize_mode_settings = std::make_unique<MaterializeMySQLSettings>();
 
@@ -243,12 +248,14 @@ DatabasePtr DatabaseFactory::getImpl(const ASTCreateQuery & create, const String
         if (engine->arguments->children.size() == 5)
             use_table_cache = safeGetLiteralValue<UInt64>(engine_args[4], engine_name);
 
-        auto parsed_host_port = parseAddress(host_port, 5432);
+        /// Split into replicas if needed.
+        size_t max_addresses = context.getSettingsRef().glob_expansion_max_elements;
+        auto addresses = parseRemoteDescriptionForExternalDatabase(host_port, max_addresses, 5432);
 
         /// no connection is made here
-        auto connection_pool = std::make_shared<PostgreSQLConnectionPool>(
+        auto connection_pool = std::make_shared<postgres::PoolWithFailover>(
             postgres_database_name,
-            parsed_host_port.first, parsed_host_port.second,
+            addresses,
             username, password,
             context.getSettingsRef().postgresql_connection_pool_size,
             context.getSettingsRef().postgresql_connection_pool_wait_timeout);

src/Databases/MySQL/DatabaseConnectionMySQL.cpp

@@ -45,8 +45,14 @@ constexpr static const auto suffix = ".remove_flag";
 static constexpr const std::chrono::seconds cleaner_sleep_time{30};
 static const std::chrono::seconds lock_acquire_timeout{10};
 
-DatabaseConnectionMySQL::DatabaseConnectionMySQL(const Context & context, const String & database_name_, const String & metadata_path_,
-    const ASTStorage * database_engine_define_, const String & database_name_in_mysql_, std::unique_ptr<ConnectionMySQLSettings> settings_, mysqlxx::Pool && pool)
+DatabaseConnectionMySQL::DatabaseConnectionMySQL(
+    const Context & context,
+    const String & database_name_,
+    const String & metadata_path_,
+    const ASTStorage * database_engine_define_,
+    const String & database_name_in_mysql_,
+    std::unique_ptr<ConnectionMySQLSettings> settings_,
+    mysqlxx::PoolWithFailover && pool)
     : IDatabase(database_name_)
     , global_context(context.getGlobalContext())
     , metadata_path(metadata_path_)

src/Databases/MySQL/DatabaseConnectionMySQL.h

@@ -10,6 +10,7 @@
 #include <Databases/DatabasesCommon.h>
 #include <Databases/MySQL/ConnectionMySQLSettings.h>
 #include <Parsers/ASTCreateQuery.h>
+#include <mysqlxx/PoolWithFailover.h>
 
 #include <atomic>
 #include <condition_variable>
@@ -36,9 +37,13 @@ public:
     ~DatabaseConnectionMySQL() override;
 
     DatabaseConnectionMySQL(
-        const Context & context, const String & database_name, const String & metadata_path,
-        const ASTStorage * database_engine_define, const String & database_name_in_mysql, std::unique_ptr<ConnectionMySQLSettings> settings_,
-        mysqlxx::Pool && pool);
+        const Context & context,
+        const String & database_name,
+        const String & metadata_path,
+        const ASTStorage * database_engine_define,
+        const String & database_name_in_mysql,
+        std::unique_ptr<ConnectionMySQLSettings> settings_,
+        mysqlxx::PoolWithFailover && pool);
 
     String getEngineName() const override { return "MySQL"; }
 
@@ -91,7 +96,7 @@ private:
     std::atomic<bool> quit{false};
     std::condition_variable cond;
 
-    using MySQLPool = mysqlxx::Pool;
+    using MySQLPool = mysqlxx::PoolWithFailover;
     using ModifyTimeAndStorage = std::pair<UInt64, StoragePtr>;
 
     mutable MySQLPool mysql_pool;

src/Databases/MySQL/FetchTablesColumnsList.cpp

@@ -41,7 +41,7 @@ namespace DB
 {
 
 std::map<String, NamesAndTypesList> fetchTablesColumnsList(
-        mysqlxx::Pool & pool,
+        mysqlxx::PoolWithFailover & pool,
         const String & database_name,
         const std::vector<String> & tables_name,
         bool external_table_functions_use_nulls,

src/Databases/MySQL/FetchTablesColumnsList.h

@@ -3,7 +3,7 @@
 #include "config_core.h"
 #if USE_MYSQL
 
-#include <mysqlxx/Pool.h>
+#include <mysqlxx/PoolWithFailover.h>
 
 #include <common/types.h>
 #include <Core/MultiEnum.h>
@@ -17,7 +17,7 @@ namespace DB
 {
 
 std::map<String, NamesAndTypesList> fetchTablesColumnsList(
-        mysqlxx::Pool & pool,
+        mysqlxx::PoolWithFailover & pool,
         const String & database_name,
         const std::vector<String> & tables_name,
         bool external_table_functions_use_nulls,

src/Databases/PostgreSQL/DatabasePostgreSQL.cpp

@@ -40,7 +40,7 @@ DatabasePostgreSQL::DatabasePostgreSQL(
         const ASTStorage * database_engine_define_,
         const String & dbname_,
         const String & postgres_dbname,
-        PostgreSQLConnectionPoolPtr connection_pool_,
+        postgres::PoolWithFailoverPtr connection_pool_,
         const bool cache_tables_)
     : IDatabase(dbname_)
     , global_context(context.getGlobalContext())
@@ -171,7 +171,7 @@ StoragePtr DatabasePostgreSQL::fetchTable(const String & table_name, const Conte
             return StoragePtr{};
 
         auto storage = StoragePostgreSQL::create(
-                StorageID(database_name, table_name), table_name, std::make_shared<PostgreSQLConnectionPool>(*connection_pool),
+                StorageID(database_name, table_name), *connection_pool, table_name,
                 ColumnsDescription{*columns}, ConstraintsDescription{}, context);
 
         if (cache_tables)

src/Databases/PostgreSQL/DatabasePostgreSQL.h

@@ -9,14 +9,13 @@
 #include <Databases/DatabasesCommon.h>
 #include <Core/BackgroundSchedulePool.h>
 #include <Parsers/ASTCreateQuery.h>
+#include <Storages/PostgreSQL/PostgreSQLPoolWithFailover.h>
 
 
 namespace DB
 {
 
 class Context;
-class PostgreSQLConnectionPool;
-using PostgreSQLConnectionPoolPtr = std::shared_ptr<PostgreSQLConnectionPool>;
 
 
 /** Real-time access to table list and table structure from remote PostgreSQL.
@@ -34,7 +33,7 @@ public:
         const ASTStorage * database_engine_define,
         const String & dbname_,
         const String & postgres_dbname,
-        PostgreSQLConnectionPoolPtr connection_pool_,
+        postgres::PoolWithFailoverPtr connection_pool_,
         const bool cache_tables_);
 
     String getEngineName() const override { return "PostgreSQL"; }
@@ -72,7 +71,7 @@ private:
     String metadata_path;
     ASTPtr database_engine_define;
     String dbname;
-    PostgreSQLConnectionPoolPtr connection_pool;
+    postgres::PoolWithFailoverPtr connection_pool;
     const bool cache_tables;
 
     mutable Tables cached_tables;

src/Databases/PostgreSQL/fetchPostgreSQLTableStructure.cpp

@@ -40,6 +40,8 @@ static DataTypePtr convertPostgreSQLDataType(std::string & type, bool is_nullabl
         res = std::make_shared<DataTypeInt32>();
     else if (type == "bigint")
         res = std::make_shared<DataTypeInt64>();
+    else if (type == "boolean")
+        res = std::make_shared<DataTypeUInt8>();
     else if (type == "real")
         res = std::make_shared<DataTypeFloat32>();
     else if (type == "double precision")
@@ -94,7 +96,7 @@ static DataTypePtr convertPostgreSQLDataType(std::string & type, bool is_nullabl
 
 
 std::shared_ptr<NamesAndTypesList> fetchPostgreSQLTableStructure(
-    PostgreSQLConnectionHolderPtr connection, const String & postgres_table_name, bool use_nulls)
+    postgres::ConnectionHolderPtr connection, const String & postgres_table_name, bool use_nulls)
 {
     auto columns = NamesAndTypesList();
 

src/Databases/PostgreSQL/fetchPostgreSQLTableStructure.h

@@ -12,7 +12,7 @@ namespace DB
 {
 
 std::shared_ptr<NamesAndTypesList> fetchPostgreSQLTableStructure(
-    PostgreSQLConnectionHolderPtr connection, const String & postgres_table_name, bool use_nulls);
+    postgres::ConnectionHolderPtr connection, const String & postgres_table_name, bool use_nulls);
 
 }
 

src/Dictionaries/LibraryDictionarySource.cpp

@@ -1,4 +1,5 @@
 #include "LibraryDictionarySource.h"
+
 #include <DataStreams/OneBlockInputStream.h>
 #include <Interpreters/Context.h>
 #include <Poco/File.h>
@@ -6,294 +7,171 @@
 #include <ext/bit_cast.h>
 #include <ext/range.h>
 #include <ext/scope_guard.h>
-#include <Common/StringUtils/StringUtils.h>
 #include "DictionarySourceFactory.h"
+#include "DictionarySourceHelpers.h"
 #include "DictionaryStructure.h"
 #include "LibraryDictionarySourceExternal.h"
 #include "registerDictionaries.h"
+#include <IO/WriteBufferFromString.h>
+#include <IO/WriteHelpers.h>
+
 
 namespace DB
 {
+
 namespace ErrorCodes
 {
-    extern const int SIZES_OF_COLUMNS_DOESNT_MATCH;
     extern const int FILE_DOESNT_EXIST;
     extern const int EXTERNAL_LIBRARY_ERROR;
     extern const int PATH_ACCESS_DENIED;
 }
 
 
-class CStringsHolder
-{
-public:
-    using Container = std::vector<std::string>;
-    explicit CStringsHolder(const Container & strings_pass)
-    {
-        strings_holder = strings_pass;
-        strings.size = strings_holder.size();
-        ptr_holder = std::make_unique<ClickHouseLibrary::CString[]>(strings.size);
-        strings.data = ptr_holder.get();
-        size_t i = 0;
-        for (auto & str : strings_holder)
-        {
-            strings.data[i] = str.c_str();
-            ++i;
-        }
-    }
-
-    ClickHouseLibrary::CStrings strings; // will pass pointer to lib
-
-private:
-    std::unique_ptr<ClickHouseLibrary::CString[]> ptr_holder = nullptr;
-    Container strings_holder;
-};
-
-
-namespace
-{
-    constexpr auto lib_config_settings = ".settings";
-
-
-    CStringsHolder getLibSettings(const Poco::Util::AbstractConfiguration & config, const std::string & config_root)
-    {
-        Poco::Util::AbstractConfiguration::Keys config_keys;
-        config.keys(config_root, config_keys);
-        CStringsHolder::Container strings;
-        for (const auto & key : config_keys)
-        {
-            std::string key_name = key;
-            auto bracket_pos = key.find('[');
-            if (bracket_pos != std::string::npos && bracket_pos > 0)
-                key_name = key.substr(0, bracket_pos);
-            strings.emplace_back(key_name);
-            strings.emplace_back(config.getString(config_root + "." + key));
-        }
-        return CStringsHolder(strings);
-    }
-
-
-    Block dataToBlock(const Block & sample_block, const ClickHouseLibrary::RawClickHouseLibraryTable data)
-    {
-        if (!data)
-            throw Exception("LibraryDictionarySource: No data returned", ErrorCodes::EXTERNAL_LIBRARY_ERROR);
-
-        const auto * columns_received = static_cast<const ClickHouseLibrary::Table *>(data);
-        if (columns_received->error_code)
-            throw Exception(
-                "LibraryDictionarySource: Returned error: " + std::to_string(columns_received->error_code) + " "
-                    + (columns_received->error_string ? columns_received->error_string : ""),
-                ErrorCodes::EXTERNAL_LIBRARY_ERROR);
-
-        MutableColumns columns = sample_block.cloneEmptyColumns();
-
-        for (size_t col_n = 0; col_n < columns_received->size; ++col_n)
-        {
-            if (columns.size() != columns_received->data[col_n].size)
-                throw Exception(
-                    "LibraryDictionarySource: Returned unexpected number of columns: " + std::to_string(columns_received->data[col_n].size)
-                        + ", must be " + std::to_string(columns.size()),
-                    ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
-
-            for (size_t row_n = 0; row_n < columns_received->data[col_n].size; ++row_n)
-            {
-                const auto & field = columns_received->data[col_n].data[row_n];
-                if (!field.data)
-                {
-                    /// sample_block contains null_value (from config) inside corresponding column
-                    const auto & col = sample_block.getByPosition(row_n);
-                    columns[row_n]->insertFrom(*(col.column), 0);
-                }
-                else
-                {
-                    const auto & size = field.size;
-                    columns[row_n]->insertData(static_cast<const char *>(field.data), size);
-                }
-            }
-        }
-
-        return sample_block.cloneWithColumns(std::move(columns));
-    }
-}
-
-
 LibraryDictionarySource::LibraryDictionarySource(
     const DictionaryStructure & dict_struct_,
     const Poco::Util::AbstractConfiguration & config,
     const std::string & config_prefix_,
     Block & sample_block_,
-    const Context & context,
+    const Context & context_,
     bool check_config)
     : log(&Poco::Logger::get("LibraryDictionarySource"))
     , dict_struct{dict_struct_}
     , config_prefix{config_prefix_}
     , path{config.getString(config_prefix + ".path", "")}
+    , dictionary_id(getDictID())
     , sample_block{sample_block_}
+    , context(context_)
 {
 
     if (check_config)
     {
         const String dictionaries_lib_path = context.getDictionariesLibPath();
         if (!startsWith(path, dictionaries_lib_path))
-            throw Exception("LibraryDictionarySource: Library path " + path + " is not inside " + dictionaries_lib_path, ErrorCodes::PATH_ACCESS_DENIED);
+            throw Exception(ErrorCodes::PATH_ACCESS_DENIED, "LibraryDictionarySource: Library path {} is not inside {}", path, dictionaries_lib_path);
     }
 
     if (!Poco::File(path).exists())
-        throw Exception(
-            "LibraryDictionarySource: Can't load library " + Poco::File(path).path() + ": file doesn't exist",
-            ErrorCodes::FILE_DOESNT_EXIST);
+        throw Exception(ErrorCodes::FILE_DOESNT_EXIST, "LibraryDictionarySource: Can't load library {}: file doesn't exist", Poco::File(path).path());
 
     description.init(sample_block);
-    library = std::make_shared<SharedLibrary>(path, RTLD_LAZY
-#if defined(RTLD_DEEPBIND) && !defined(ADDRESS_SANITIZER) // Does not exists in FreeBSD. Cannot work with Address Sanitizer.
-        | RTLD_DEEPBIND
-#endif
-    );
-    settings = std::make_shared<CStringsHolder>(getLibSettings(config, config_prefix + lib_config_settings));
+    bridge_helper = std::make_shared<LibraryBridgeHelper>(context, description.sample_block, dictionary_id);
+    auto res = bridge_helper->initLibrary(path, getLibrarySettingsString(config, config_prefix + ".settings"), getDictAttributesString());
 
-    if (auto lib_new = library->tryGet<ClickHouseLibrary::LibraryNewFunc>(ClickHouseLibrary::LIBRARY_CREATE_NEW_FUNC_NAME))
-        lib_data = lib_new(&settings->strings, ClickHouseLibrary::log);
+    if (!res)
+        throw Exception(ErrorCodes::EXTERNAL_LIBRARY_ERROR, "Failed to create shared library from path: {}", path);
 }
 
+
+LibraryDictionarySource::~LibraryDictionarySource()
+{
+    bridge_helper->removeLibrary();
+}
+
+
 LibraryDictionarySource::LibraryDictionarySource(const LibraryDictionarySource & other)
     : log(&Poco::Logger::get("LibraryDictionarySource"))
     , dict_struct{other.dict_struct}
     , config_prefix{other.config_prefix}
     , path{other.path}
+    , dictionary_id{getDictID()}
     , sample_block{other.sample_block}
-    , library{other.library}
+    , context(other.context)
     , description{other.description}
-    , settings{other.settings}
 {
-    if (auto lib_clone = library->tryGet<ClickHouseLibrary::LibraryCloneFunc>(ClickHouseLibrary::LIBRARY_CLONE_FUNC_NAME))
-        lib_data = lib_clone(other.lib_data);
-    else if (auto lib_new = library->tryGet<ClickHouseLibrary::LibraryNewFunc>(ClickHouseLibrary::LIBRARY_CREATE_NEW_FUNC_NAME))
-        lib_data = lib_new(&settings->strings, ClickHouseLibrary::log);
+    bridge_helper = std::make_shared<LibraryBridgeHelper>(context, description.sample_block, dictionary_id);
+    bridge_helper->cloneLibrary(other.dictionary_id);
 }
 
-LibraryDictionarySource::~LibraryDictionarySource()
+
+bool LibraryDictionarySource::isModified() const
 {
-    if (auto lib_delete = library->tryGet<ClickHouseLibrary::LibraryDeleteFunc>(ClickHouseLibrary::LIBRARY_DELETE_FUNC_NAME))
-        lib_delete(lib_data);
+    return bridge_helper->isModified();
 }
 
+
+bool LibraryDictionarySource::supportsSelectiveLoad() const
+{
+    return bridge_helper->supportsSelectiveLoad();
+}
+
+
 BlockInputStreamPtr LibraryDictionarySource::loadAll()
 {
     LOG_TRACE(log, "loadAll {}", toString());
-
-    auto columns_holder = std::make_unique<ClickHouseLibrary::CString[]>(dict_struct.attributes.size());
-    ClickHouseLibrary::CStrings columns{static_cast<decltype(ClickHouseLibrary::CStrings::data)>(columns_holder.get()),
-                                        dict_struct.attributes.size()};
-    size_t i = 0;
-    for (const auto & a : dict_struct.attributes)
-    {
-        columns.data[i] = a.name.c_str();
-        ++i;
-    }
-
-    auto load_all_func = library->get<ClickHouseLibrary::LibraryLoadAllFunc>(ClickHouseLibrary::LIBRARY_LOAD_ALL_FUNC_NAME);
-    auto data_new_func = library->get<ClickHouseLibrary::LibraryDataNewFunc>(ClickHouseLibrary::LIBRARY_DATA_NEW_FUNC_NAME);
-    auto data_delete_func = library->get<ClickHouseLibrary::LibraryDataDeleteFunc>(ClickHouseLibrary::LIBRARY_DATA_DELETE_FUNC_NAME);
-
-    ClickHouseLibrary::LibraryData data_ptr = data_new_func(lib_data);
-    SCOPE_EXIT(data_delete_func(lib_data, data_ptr));
-
-    ClickHouseLibrary::RawClickHouseLibraryTable data = load_all_func(data_ptr, &settings->strings, &columns);
-    auto block = dataToBlock(description.sample_block, data);
-
-    return std::make_shared<OneBlockInputStream>(block);
+    return bridge_helper->loadAll();
 }
 
+
 BlockInputStreamPtr LibraryDictionarySource::loadIds(const std::vector<UInt64> & ids)
 {
     LOG_TRACE(log, "loadIds {} size = {}", toString(), ids.size());
-
-    const ClickHouseLibrary::VectorUInt64 ids_data{ext::bit_cast<decltype(ClickHouseLibrary::VectorUInt64::data)>(ids.data()), ids.size()};
-    auto columns_holder = std::make_unique<ClickHouseLibrary::CString[]>(dict_struct.attributes.size());
-    ClickHouseLibrary::CStrings columns_pass{static_cast<decltype(ClickHouseLibrary::CStrings::data)>(columns_holder.get()),
-                                             dict_struct.attributes.size()};
-    size_t i = 0;
-    for (const auto & a : dict_struct.attributes)
-    {
-        columns_pass.data[i] = a.name.c_str();
-        ++i;
-    }
-
-    auto load_ids_func = library->get<ClickHouseLibrary::LibraryLoadIdsFunc>(ClickHouseLibrary::LIBRARY_LOAD_IDS_FUNC_NAME);
-    auto data_new_func = library->get<ClickHouseLibrary::LibraryDataNewFunc>(ClickHouseLibrary::LIBRARY_DATA_NEW_FUNC_NAME);
-    auto data_delete_func = library->get<ClickHouseLibrary::LibraryDataDeleteFunc>(ClickHouseLibrary::LIBRARY_DATA_DELETE_FUNC_NAME);
-
-    ClickHouseLibrary::LibraryData data_ptr = data_new_func(lib_data);
-    SCOPE_EXIT(data_delete_func(lib_data, data_ptr));
-
-    ClickHouseLibrary::RawClickHouseLibraryTable data = load_ids_func(data_ptr, &settings->strings, &columns_pass, &ids_data);
-    auto block = dataToBlock(description.sample_block, data);
-
-    return std::make_shared<OneBlockInputStream>(block);
+    return bridge_helper->loadIds(getDictIdsString(ids));
 }
 
+
 BlockInputStreamPtr LibraryDictionarySource::loadKeys(const Columns & key_columns, const std::vector<std::size_t> & requested_rows)
 {
     LOG_TRACE(log, "loadKeys {} size = {}", toString(), requested_rows.size());
-
-    auto holder = std::make_unique<ClickHouseLibrary::Row[]>(key_columns.size());
-    std::vector<std::unique_ptr<ClickHouseLibrary::Field[]>> column_data_holders;
-    for (size_t i = 0; i < key_columns.size(); ++i)
-    {
-        auto cell_holder = std::make_unique<ClickHouseLibrary::Field[]>(requested_rows.size());
-        for (size_t j = 0; j < requested_rows.size(); ++j)
-        {
-            auto data_ref = key_columns[i]->getDataAt(requested_rows[j]);
-            cell_holder[j] = ClickHouseLibrary::Field{.data = static_cast<const void *>(data_ref.data), .size = data_ref.size};
-        }
-        holder[i]
-            = ClickHouseLibrary::Row{.data = static_cast<ClickHouseLibrary::Field *>(cell_holder.get()), .size = requested_rows.size()};
-
-        column_data_holders.push_back(std::move(cell_holder));
-    }
-
-    ClickHouseLibrary::Table request_cols{.data = static_cast<ClickHouseLibrary::Row *>(holder.get()), .size = key_columns.size()};
-
-    auto load_keys_func = library->get<ClickHouseLibrary::LibraryLoadKeysFunc>(ClickHouseLibrary::LIBRARY_LOAD_KEYS_FUNC_NAME);
-    auto data_new_func = library->get<ClickHouseLibrary::LibraryDataNewFunc>(ClickHouseLibrary::LIBRARY_DATA_NEW_FUNC_NAME);
-    auto data_delete_func = library->get<ClickHouseLibrary::LibraryDataDeleteFunc>(ClickHouseLibrary::LIBRARY_DATA_DELETE_FUNC_NAME);
-
-    ClickHouseLibrary::LibraryData data_ptr = data_new_func(lib_data);
-    SCOPE_EXIT(data_delete_func(lib_data, data_ptr));
-
-    ClickHouseLibrary::RawClickHouseLibraryTable data = load_keys_func(data_ptr, &settings->strings, &request_cols);
-    auto block = dataToBlock(description.sample_block, data);
-
-    return std::make_shared<OneBlockInputStream>(block);
+    auto block = blockForKeys(dict_struct, key_columns, requested_rows);
+    return bridge_helper->loadKeys(block);
 }
 
-bool LibraryDictionarySource::isModified() const
-{
-    if (auto func_is_modified = library->tryGet<ClickHouseLibrary::LibraryIsModifiedFunc>(
-        ClickHouseLibrary::LIBRARY_IS_MODIFIED_FUNC_NAME))
-        return func_is_modified(lib_data, &settings->strings);
-
-    return true;
-}
-
-bool LibraryDictionarySource::supportsSelectiveLoad() const
-{
-    if (auto func_supports_selective_load = library->tryGet<ClickHouseLibrary::LibrarySupportsSelectiveLoadFunc>(
-            ClickHouseLibrary::LIBRARY_SUPPORTS_SELECTIVE_LOAD_FUNC_NAME))
-        return func_supports_selective_load(lib_data, &settings->strings);
-
-    return true;
-}
 
 DictionarySourcePtr LibraryDictionarySource::clone() const
 {
     return std::make_unique<LibraryDictionarySource>(*this);
 }
 
+
 std::string LibraryDictionarySource::toString() const
 {
     return path;
 }
 
+
+String LibraryDictionarySource::getLibrarySettingsString(const Poco::Util::AbstractConfiguration & config, const std::string & config_root)
+{
+    Poco::Util::AbstractConfiguration::Keys config_keys;
+    config.keys(config_root, config_keys);
+    WriteBufferFromOwnString out;
+    std::vector<std::string> settings;
+
+    for (const auto & key : config_keys)
+    {
+        std::string key_name = key;
+        auto bracket_pos = key.find('[');
+
+        if (bracket_pos != std::string::npos && bracket_pos > 0)
+            key_name = key.substr(0, bracket_pos);
+
+        settings.push_back(key_name);
+        settings.push_back(config.getString(config_root + "." + key));
+    }
+
+    writeVectorBinary(settings, out);
+    return out.str();
+}
+
+
+String LibraryDictionarySource::getDictIdsString(const std::vector<UInt64> & ids)
+{
+    WriteBufferFromOwnString out;
+    writeVectorBinary(ids, out);
+    return out.str();
+}
+
+
+String LibraryDictionarySource::getDictAttributesString()
+{
+    std::vector<String> attributes_names(dict_struct.attributes.size());
+    for (size_t i = 0; i < dict_struct.attributes.size(); ++i)
+        attributes_names[i] = dict_struct.attributes[i].name;
+    WriteBufferFromOwnString out;
+    writeVectorBinary(attributes_names, out);
+    return out.str();
+}
+
+
 void registerDictionarySourceLibrary(DictionarySourceFactory & factory)
 {
     auto create_table_source = [=](const DictionaryStructure & dict_struct,
@@ -306,7 +184,9 @@ void registerDictionarySourceLibrary(DictionarySourceFactory & factory)
     {
         return std::make_unique<LibraryDictionarySource>(dict_struct, config, config_prefix + ".library", sample_block, context, check_config);
     };
+
     factory.registerSource("library", create_table_source);
 }
 
+
 }

src/Dictionaries/LibraryDictionarySource.h

@@ -1,7 +1,9 @@
 #pragma once
 
 #include <Common/SharedLibrary.h>
+#include <Bridge/LibraryBridgeHelper.h>
 #include <common/LocalDateTime.h>
+#include <Core/UUID.h>
 #include "DictionaryStructure.h"
 #include <Core/ExternalResultDescription.h>
 #include "IDictionarySource.h"
@@ -17,18 +19,17 @@ namespace Util
 }
 }
 
-
 namespace DB
 {
+
 namespace ErrorCodes
 {
     extern const int NOT_IMPLEMENTED;
 }
-class CStringsHolder;
 
-/// Allows loading dictionaries from dynamic libraries (.so)
-/// Experimental version
-/// Example: tests/external_dictionaries/dictionary_library/dictionary_library.cpp
+class CStringsHolder;
+using LibraryBridgeHelperPtr = std::shared_ptr<LibraryBridgeHelper>;
+
 class LibraryDictionarySource final : public IDictionarySource
 {
 public:
@@ -37,7 +38,7 @@ public:
         const Poco::Util::AbstractConfiguration & config,
         const std::string & config_prefix_,
         Block & sample_block_,
-        const Context & context,
+        const Context & context_,
         bool check_config);
 
     LibraryDictionarySource(const LibraryDictionarySource & other);
@@ -68,18 +69,26 @@ public:
     std::string toString() const override;
 
 private:
-    Poco::Logger * log;
+    static String getDictIdsString(const std::vector<UInt64> & ids);
 
-    LocalDateTime getLastModification() const;
+    String getDictAttributesString();
+
+    static String getLibrarySettingsString(const Poco::Util::AbstractConfiguration & config, const std::string & config_root);
+
+    static Field getDictID() { return UUIDHelpers::generateV4(); }
+
+    Poco::Logger * log;
 
     const DictionaryStructure dict_struct;
     const std::string config_prefix;
     const std::string path;
+    const Field dictionary_id;
+
     Block sample_block;
-    SharedLibraryPtr library;
+    Context context;
+
+    LibraryBridgeHelperPtr bridge_helper;
     ExternalResultDescription description;
-    std::shared_ptr<CStringsHolder> settings;
-    void * lib_data = nullptr;
 };
 
 }

src/Dictionaries/MySQLDictionarySource.cpp

@@ -70,7 +70,7 @@ MySQLDictionarySource::MySQLDictionarySource(
     , update_field{config.getString(config_prefix + ".update_field", "")}
     , dont_check_update_time{config.getBool(config_prefix + ".dont_check_update_time", false)}
     , sample_block{sample_block_}
-    , pool{mysqlxx::PoolFactory::instance().get(config, config_prefix)}
+    , pool{std::make_shared<mysqlxx::PoolWithFailover>(mysqlxx::PoolFactory::instance().get(config, config_prefix))}
     , query_builder{dict_struct, db, "", table, where, IdentifierQuotingStyle::Backticks}
     , load_all_query{query_builder.composeLoadAllQuery()}
     , invalidate_query{config.getString(config_prefix + ".invalidate_query", "")}
@@ -119,67 +119,43 @@ std::string MySQLDictionarySource::getUpdateFieldAndDate()
     }
 }
 
-BlockInputStreamPtr MySQLDictionarySource::retriedCreateMySqlBIStream(const std::string & data_fetch_query_str, const size_t max_tries)
+BlockInputStreamPtr MySQLDictionarySource::loadFromQuery(const String & query)
 {
-    size_t count_connection_lost = 0;
-
-    while (true)
-    {
-        auto connection = pool.get();
-
-        try
-        {
-            return std::make_shared<MySQLBlockInputStream>(
-                    connection, data_fetch_query_str, sample_block, max_block_size, close_connection);
-        }
-        catch (const mysqlxx::ConnectionLost & ecl)  /// There are two retriable failures: CR_SERVER_GONE_ERROR, CR_SERVER_LOST
-        {
-            if (++count_connection_lost < max_tries)
-            {
-                LOG_WARNING(log, ecl.displayText());
-                LOG_WARNING(log, "Lost connection ({}/{}). Trying to reconnect...", count_connection_lost, max_tries);
-                continue;
-            }
-
-            LOG_ERROR(log, "Failed ({}/{}) to create BlockInputStream for MySQL dictionary source.", count_connection_lost, max_tries);
-            throw;
-        }
-    }
+    return std::make_shared<MySQLWithFailoverBlockInputStream>(
+            pool, query, sample_block, max_block_size, close_connection, false, max_tries_for_mysql_block_input_stream);
 }
 
 BlockInputStreamPtr MySQLDictionarySource::loadAll()
 {
-    auto connection = pool.get();
+    auto connection = pool->get();
     last_modification = getLastModification(connection, false);
 
     LOG_TRACE(log, load_all_query);
-    return retriedCreateMySqlBIStream(load_all_query, max_tries_for_mysql_block_input_stream);
+    return loadFromQuery(load_all_query);
 }
 
 BlockInputStreamPtr MySQLDictionarySource::loadUpdatedAll()
 {
-    auto connection = pool.get();
+    auto connection = pool->get();
     last_modification = getLastModification(connection, false);
 
     std::string load_update_query = getUpdateFieldAndDate();
     LOG_TRACE(log, load_update_query);
-    return retriedCreateMySqlBIStream(load_update_query, max_tries_for_mysql_block_input_stream);
+    return loadFromQuery(load_update_query);
 }
 
 BlockInputStreamPtr MySQLDictionarySource::loadIds(const std::vector<UInt64> & ids)
 {
     /// We do not log in here and do not update the modification time, as the request can be large, and often called.
-
     const auto query = query_builder.composeLoadIdsQuery(ids);
-    return retriedCreateMySqlBIStream(query, max_tries_for_mysql_block_input_stream);
+    return loadFromQuery(query);
 }
 
 BlockInputStreamPtr MySQLDictionarySource::loadKeys(const Columns & key_columns, const std::vector<size_t> & requested_rows)
 {
     /// We do not log in here and do not update the modification time, as the request can be large, and often called.
-
     const auto query = query_builder.composeLoadKeysQuery(key_columns, requested_rows, ExternalQueryBuilder::AND_OR_CHAIN);
-    return retriedCreateMySqlBIStream(query, max_tries_for_mysql_block_input_stream);
+    return loadFromQuery(query);
 }
 
 bool MySQLDictionarySource::isModified() const
@@ -195,7 +171,7 @@ bool MySQLDictionarySource::isModified() const
 
     if (dont_check_update_time)
         return true;
-    auto connection = pool.get();
+    auto connection = pool->get();
     return getLastModification(connection, true) > last_modification;
 }
 
@@ -293,7 +269,7 @@ std::string MySQLDictionarySource::doInvalidateQuery(const std::string & request
     Block invalidate_sample_block;
     ColumnPtr column(ColumnString::create());
     invalidate_sample_block.insert(ColumnWithTypeAndName(column, std::make_shared<DataTypeString>(), "Sample Block"));
-    MySQLBlockInputStream block_input_stream(pool.get(), request, invalidate_sample_block, 1, close_connection);
+    MySQLBlockInputStream block_input_stream(pool->get(), request, invalidate_sample_block, 1, close_connection);
     return readInvalidateQuery(block_input_stream);
 }
 

src/Dictionaries/MySQLDictionarySource.h

@@ -34,7 +34,7 @@ public:
     MySQLDictionarySource(
         const DictionaryStructure & dict_struct_,
         const Poco::Util::AbstractConfiguration & config,
-        const std::string & config_prefix,
+        const String & config_prefix,
         const Block & sample_block_);
 
     /// copy-constructor is provided in order to support cloneability
@@ -60,6 +60,8 @@ public:
     std::string toString() const override;
 
 private:
+    BlockInputStreamPtr loadFromQuery(const String & query);
+
     std::string getUpdateFieldAndDate();
 
     static std::string quoteForLike(const std::string s);
@@ -69,9 +71,6 @@ private:
     // execute invalidate_query. expects single cell in result
     std::string doInvalidateQuery(const std::string & request) const;
 
-    /// A helper method for recovering from "Lost connection to MySQL server during query" errors
-    BlockInputStreamPtr retriedCreateMySqlBIStream(const std::string & query_str, const size_t max_tries);
-
     Poco::Logger * log;
 
     std::chrono::time_point<std::chrono::system_clock> update_time;
@@ -82,7 +81,7 @@ private:
     const std::string update_field;
     const bool dont_check_update_time;
     Block sample_block;
-    mutable mysqlxx::PoolWithFailover pool;
+    mutable mysqlxx::PoolWithFailoverPtr pool;
     ExternalQueryBuilder query_builder;
     const std::string load_all_query;
     LocalDateTime last_modification;

src/Dictionaries/PostgreSQLDictionarySource.cpp

@@ -31,7 +31,7 @@ PostgreSQLDictionarySource::PostgreSQLDictionarySource(
     const Block & sample_block_)
     : dict_struct{dict_struct_}
     , sample_block(sample_block_)
-    , connection(std::make_shared<PostgreSQLReplicaConnection>(config_, config_prefix))
+    , connection(std::make_shared<postgres::PoolWithFailover>(config_, config_prefix))
     , log(&Poco::Logger::get("PostgreSQLDictionarySource"))
     , db(config_.getString(fmt::format("{}.db", config_prefix), ""))
     , table(config_.getString(fmt::format("{}.table", config_prefix), ""))

src/Dictionaries/PostgreSQLDictionarySource.h

@@ -11,7 +11,7 @@
 #include <Core/Block.h>
 #include <common/LocalDateTime.h>
 #include <common/logger_useful.h>
-#include <Storages/PostgreSQL/PostgreSQLReplicaConnection.h>
+#include <Storages/PostgreSQL/PostgreSQLPoolWithFailover.h>
 #include <pqxx/pqxx>
 
 
@@ -51,7 +51,7 @@ private:
 
     const DictionaryStructure dict_struct;
     Block sample_block;
-    PostgreSQLReplicaConnectionPtr connection;
+    postgres::PoolWithFailoverPtr connection;
     Poco::Logger * log;
 
     const std::string db;

src/Dictionaries/XDBCDictionarySource.cpp

@@ -11,7 +11,6 @@
 #include <Interpreters/Context.h>
 #include <Poco/Net/HTTPRequest.h>
 #include <Poco/Util/AbstractConfiguration.h>
-#include <Common/XDBCBridgeHelper.h>
 #include <common/LocalDateTime.h>
 #include <common/logger_useful.h>
 #include "DictionarySourceFactory.h"

src/Dictionaries/XDBCDictionarySource.h

@@ -3,7 +3,7 @@
 #include <IO/ConnectionTimeouts.h>
 #include <Poco/Data/SessionPool.h>
 #include <Poco/URI.h>
-#include <Common/XDBCBridgeHelper.h>
+#include <Bridge/XDBCBridgeHelper.h>
 #include "DictionaryStructure.h"
 #include "ExternalQueryBuilder.h"
 #include "IDictionarySource.h"

src/Formats/MySQLBlockInputStream.cpp

@@ -1,26 +1,29 @@
 #if !defined(ARCADIA_BUILD)
-#    include "config_core.h"
+#include "config_core.h"
 #endif
 
 #if USE_MYSQL
-#    include <vector>
-#    include <Columns/ColumnNullable.h>
-#    include <Columns/ColumnString.h>
-#    include <Columns/ColumnsNumber.h>
-#    include <Columns/ColumnDecimal.h>
-#    include <Columns/ColumnFixedString.h>
-#    include <DataTypes/IDataType.h>
-#    include <DataTypes/DataTypeNullable.h>
-#    include <IO/ReadBufferFromString.h>
-#    include <IO/ReadHelpers.h>
-#    include <IO/WriteHelpers.h>
-#    include <IO/Operators.h>
-#    include <Common/assert_cast.h>
-#    include <ext/range.h>
-#    include "MySQLBlockInputStream.h"
+#include <vector>
+#include <Columns/ColumnNullable.h>
+#include <Columns/ColumnString.h>
+#include <Columns/ColumnsNumber.h>
+#include <Columns/ColumnDecimal.h>
+#include <Columns/ColumnFixedString.h>
+#include <DataTypes/IDataType.h>
+#include <DataTypes/DataTypeNullable.h>
+#include <IO/ReadBufferFromString.h>
+#include <IO/ReadHelpers.h>
+#include <IO/WriteHelpers.h>
+#include <IO/Operators.h>
+#include <Common/assert_cast.h>
+#include <ext/range.h>
+#include <common/logger_useful.h>
+#include "MySQLBlockInputStream.h"
+
 
 namespace DB
 {
+
 namespace ErrorCodes
 {
     extern const int NUMBER_OF_COLUMNS_DOESNT_MATCH;
@@ -36,6 +39,7 @@ MySQLBlockInputStream::Connection::Connection(
 {
 }
 
+/// Used in MaterializeMySQL and in doInvalidateQuery for dictionary source.
 MySQLBlockInputStream::MySQLBlockInputStream(
     const mysqlxx::PoolWithFailover::Entry & entry,
     const std::string & query_str,
@@ -43,7 +47,8 @@ MySQLBlockInputStream::MySQLBlockInputStream(
     const UInt64 max_block_size_,
     const bool auto_close_,
     const bool fetch_by_name_)
-    : connection{std::make_unique<Connection>(entry, query_str)}
+    : log(&Poco::Logger::get("MySQLBlockInputStream"))
+    , connection{std::make_unique<Connection>(entry, query_str)}
     , max_block_size{max_block_size_}
     , auto_close{auto_close_}
     , fetch_by_name(fetch_by_name_)
@@ -52,6 +57,62 @@ MySQLBlockInputStream::MySQLBlockInputStream(
     initPositionMappingFromQueryResultStructure();
 }
 
+/// For descendant MySQLWithFailoverBlockInputStream
+MySQLBlockInputStream::MySQLBlockInputStream(
+    const Block & sample_block_,
+    UInt64 max_block_size_,
+    bool auto_close_,
+    bool fetch_by_name_)
+    : log(&Poco::Logger::get("MySQLBlockInputStream"))
+    , max_block_size(max_block_size_)
+    , auto_close(auto_close_)
+    , fetch_by_name(fetch_by_name_)
+{
+    description.init(sample_block_);
+}
+
+/// Used by MySQL storage / table function and dictionary source.
+MySQLWithFailoverBlockInputStream::MySQLWithFailoverBlockInputStream(
+    mysqlxx::PoolWithFailoverPtr pool_,
+    const std::string & query_str_,
+    const Block & sample_block_,
+    const UInt64 max_block_size_,
+    const bool auto_close_,
+    const bool fetch_by_name_,
+    const size_t max_tries_)
+    : MySQLBlockInputStream(sample_block_, max_block_size_, auto_close_, fetch_by_name_)
+    , pool(pool_)
+    , query_str(query_str_)
+    , max_tries(max_tries_)
+{
+}
+
+void MySQLWithFailoverBlockInputStream::readPrefix()
+{
+    size_t count_connect_attempts = 0;
+
+    /// For recovering from "Lost connection to MySQL server during query" errors
+    while (true)
+    {
+        try
+        {
+            connection = std::make_unique<Connection>(pool->get(), query_str);
+            break;
+        }
+        catch (const mysqlxx::ConnectionLost & ecl)  /// There are two retriable failures: CR_SERVER_GONE_ERROR, CR_SERVER_LOST
+        {
+            LOG_WARNING(log, "Failed connection ({}/{}). Trying to reconnect... (Info: {})", count_connect_attempts, max_tries, ecl.displayText());
+        }
+
+        if (++count_connect_attempts > max_tries)
+        {
+            LOG_ERROR(log, "Failed to create connection to MySQL. ({}/{})", count_connect_attempts, max_tries);
+            throw;
+        }
+    }
+
+    initPositionMappingFromQueryResultStructure();
+}
 
 namespace
 {
@@ -139,6 +200,7 @@ Block MySQLBlockInputStream::readImpl()
     {
         if (auto_close)
            connection->entry.disconnect();
+
         return {};
     }
 
@@ -191,18 +253,6 @@ Block MySQLBlockInputStream::readImpl()
     return description.sample_block.cloneWithColumns(std::move(columns));
 }
 
-MySQLBlockInputStream::MySQLBlockInputStream(
-    const Block & sample_block_,
-    UInt64 max_block_size_,
-    bool auto_close_,
-    bool fetch_by_name_)
-    : max_block_size(max_block_size_)
-    , auto_close(auto_close_)
-    , fetch_by_name(fetch_by_name_)
-{
-    description.init(sample_block_);
-}
-
 void MySQLBlockInputStream::initPositionMappingFromQueryResultStructure()
 {
     position_mapping.resize(description.sample_block.columns());
@@ -250,25 +300,6 @@ void MySQLBlockInputStream::initPositionMappingFromQueryResultStructure()
     }
 }
 
-MySQLLazyBlockInputStream::MySQLLazyBlockInputStream(
-    mysqlxx::Pool & pool_,
-    const std::string & query_str_,
-    const Block & sample_block_,
-    const UInt64 max_block_size_,
-    const bool auto_close_,
-    const bool fetch_by_name_)
-    : MySQLBlockInputStream(sample_block_, max_block_size_, auto_close_, fetch_by_name_)
-    , pool(pool_)
-    , query_str(query_str_)
-{
-}
-
-void MySQLLazyBlockInputStream::readPrefix()
-{
-    connection = std::make_unique<Connection>(pool.get(), query_str);
-    initPositionMappingFromQueryResultStructure();
-}
-
 }
 
 #endif

src/Formats/MySQLBlockInputStream.h

@@ -41,6 +41,7 @@ protected:
         mysqlxx::UseQueryResult result;
     };
 
+    Poco::Logger * log;
     std::unique_ptr<Connection> connection;
 
     const UInt64 max_block_size;
@@ -52,22 +53,27 @@ protected:
 
 /// Like MySQLBlockInputStream, but allocates connection only when reading is starting.
 /// It allows to create a lot of stream objects without occupation of all connection pool.
-class MySQLLazyBlockInputStream final : public MySQLBlockInputStream
+/// Also makes attempts to reconnect in case of connection failures.
+class MySQLWithFailoverBlockInputStream final : public MySQLBlockInputStream
 {
 public:
-    MySQLLazyBlockInputStream(
-        mysqlxx::Pool & pool_,
+    static constexpr inline auto MAX_TRIES_MYSQL_CONNECT = 5;
+
+    MySQLWithFailoverBlockInputStream(
+        mysqlxx::PoolWithFailoverPtr pool_,
         const std::string & query_str_,
         const Block & sample_block_,
         const UInt64 max_block_size_,
         const bool auto_close_ = false,
-        const bool fetch_by_name_ = false);
+        const bool fetch_by_name_ = false,
+        const size_t max_tries_ = MAX_TRIES_MYSQL_CONNECT);
 
 private:
     void readPrefix() override;
 
-    mysqlxx::Pool & pool;
+    mysqlxx::PoolWithFailoverPtr pool;
     std::string query_str;
+    size_t max_tries;
 };
 
 }

src/Interpreters/Context.cpp

@@ -2358,7 +2358,7 @@ void Context::setQueryParameter(const String & name, const String & value)
 }
 
 
-void Context::addXDBCBridgeCommand(std::unique_ptr<ShellCommand> cmd) const
+void Context::addBridgeCommand(std::unique_ptr<ShellCommand> cmd) const
 {
     auto lock = getLock();
     shared->bridge_commands.emplace_back(std::move(cmd));

src/Interpreters/Context.h

@@ -747,7 +747,7 @@ public:
     void setQueryParameters(const NameToNameMap & parameters) { query_parameters = parameters; }
 
     /// Add started bridge command. It will be killed after context destruction
-    void addXDBCBridgeCommand(std::unique_ptr<ShellCommand> cmd) const;
+    void addBridgeCommand(std::unique_ptr<ShellCommand> cmd) const;
 
     IHostContextPtr & getHostContext();
     const IHostContextPtr & getHostContext() const;

src/Interpreters/ExpressionActions.cpp

@@ -522,6 +522,10 @@ std::string ExpressionActions::getSmallestColumn(const NamesAndTypesList & colum
 
     for (const auto & column : columns)
     {
+        /// Skip .sizeX and similar meta information
+        if (!column.getSubcolumnName().empty())
+            continue;
+
         /// @todo resolve evil constant
         size_t size = column.type->haveMaximumSizeOfValue() ? column.type->getMaximumSizeOfValueInMemory() : 100;
 

src/Interpreters/InterpreterInsertQuery.cpp

@@ -9,21 +9,17 @@
 #include <DataStreams/NullAndDoCopyBlockInputStream.h>
 #include <DataStreams/NullBlockOutputStream.h>
 #include <DataStreams/PushingToViewsBlockOutputStream.h>
-#include <DataStreams/RemoteBlockInputStream.h>
 #include <DataStreams/SquashingBlockOutputStream.h>
 #include <DataStreams/copyData.h>
 #include <IO/ConnectionTimeoutsContext.h>
 #include <Interpreters/InterpreterSelectWithUnionQuery.h>
 #include <Interpreters/InterpreterWatchQuery.h>
-#include <Interpreters/JoinedTables.h>
 #include <Parsers/ASTFunction.h>
 #include <Parsers/ASTIdentifier.h>
 #include <Parsers/ASTInsertQuery.h>
 #include <Parsers/ASTSelectQuery.h>
 #include <Parsers/ASTSelectWithUnionQuery.h>
 #include <Parsers/ASTTablesInSelectQuery.h>
-#include <Parsers/queryToString.h>
-#include <Processors/NullSink.h>
 #include <Processors/Sources/SinkToOutputStream.h>
 #include <Processors/Sources/SourceFromInputStream.h>
 #include <Processors/Transforms/ExpressionTransform.h>
@@ -36,11 +32,6 @@
 #include <Interpreters/getTableExpressions.h>
 #include <Interpreters/processColumnTransformers.h>
 
-namespace
-{
-const UInt64 PARALLEL_DISTRIBUTED_INSERT_SELECT_ALL = 2;
-}
-
 
 namespace DB
 {
@@ -50,7 +41,6 @@ namespace ErrorCodes
     extern const int NO_SUCH_COLUMN_IN_TABLE;
     extern const int ILLEGAL_COLUMN;
     extern const int DUPLICATE_COLUMN;
-    extern const int LOGICAL_ERROR;
 }
 
 InterpreterInsertQuery::InterpreterInsertQuery(
@@ -178,79 +168,10 @@ BlockIO InterpreterInsertQuery::execute()
     if (query.select && table->isRemote() && settings.parallel_distributed_insert_select)
     {
         // Distributed INSERT SELECT
-        std::shared_ptr<StorageDistributed> storage_src;
-        auto & select = query.select->as<ASTSelectWithUnionQuery &>();
-        auto new_query = std::dynamic_pointer_cast<ASTInsertQuery>(query.clone());
-        if (select.list_of_selects->children.size() == 1)
-        {
-            if (auto * select_query = select.list_of_selects->children.at(0)->as<ASTSelectQuery>())
-            {
-                JoinedTables joined_tables(Context(context), *select_query);
-
-                if (joined_tables.tablesCount() == 1)
-                {
-                    storage_src = std::dynamic_pointer_cast<StorageDistributed>(joined_tables.getLeftTableStorage());
-                    if (storage_src)
-                    {
-                        const auto select_with_union_query = std::make_shared<ASTSelectWithUnionQuery>();
-                        select_with_union_query->list_of_selects = std::make_shared<ASTExpressionList>();
-
-                        auto new_select_query = std::dynamic_pointer_cast<ASTSelectQuery>(select_query->clone());
-                        select_with_union_query->list_of_selects->children.push_back(new_select_query);
-
-                        new_select_query->replaceDatabaseAndTable(storage_src->getRemoteDatabaseName(), storage_src->getRemoteTableName());
-
-                        new_query->select = select_with_union_query;
-                    }
-                }
-            }
-        }
-
-        auto storage_dst = std::dynamic_pointer_cast<StorageDistributed>(table);
-
-        if (storage_src && storage_dst && storage_src->getClusterName() == storage_dst->getClusterName())
+        if (auto maybe_pipeline = table->distributedWrite(query, context))
         {
+            res.pipeline = std::move(*maybe_pipeline);
             is_distributed_insert_select = true;
-
-            if (settings.parallel_distributed_insert_select == PARALLEL_DISTRIBUTED_INSERT_SELECT_ALL)
-            {
-                new_query->table_id = StorageID(storage_dst->getRemoteDatabaseName(), storage_dst->getRemoteTableName());
-            }
-
-            const auto & cluster = storage_src->getCluster();
-            const auto & shards_info = cluster->getShardsInfo();
-
-            std::vector<std::unique_ptr<QueryPipeline>> pipelines;
-
-            String new_query_str = queryToString(new_query);
-            for (size_t shard_index : ext::range(0, shards_info.size()))
-            {
-                const auto & shard_info = shards_info[shard_index];
-                if (shard_info.isLocal())
-                {
-                    InterpreterInsertQuery interpreter(new_query, context);
-                    pipelines.emplace_back(std::make_unique<QueryPipeline>(interpreter.execute().pipeline));
-                }
-                else
-                {
-                    auto timeouts = ConnectionTimeouts::getTCPTimeoutsWithFailover(settings);
-                    auto connections = shard_info.pool->getMany(timeouts, &settings, PoolMode::GET_ONE);
-                    if (connections.empty() || connections.front().isNull())
-                        throw Exception(
-                            "Expected exactly one connection for shard " + toString(shard_info.shard_num), ErrorCodes::LOGICAL_ERROR);
-
-                    ///  INSERT SELECT query returns empty block
-                    auto in_stream = std::make_shared<RemoteBlockInputStream>(std::move(connections), new_query_str, Block{}, context);
-                    pipelines.emplace_back(std::make_unique<QueryPipeline>());
-                    pipelines.back()->init(Pipe(std::make_shared<SourceFromInputStream>(std::move(in_stream))));
-                    pipelines.back()->setSinks([](const Block & header, QueryPipeline::StreamType) -> ProcessorPtr
-                    {
-                        return std::make_shared<EmptySink>(header);
-                    });
-                }
-            }
-
-            res.pipeline = QueryPipeline::unitePipelines(std::move(pipelines), {}, ExpressionActionsSettings::fromContext(context));
         }
     }
 

src/Parsers/ASTFunction.cpp

@@ -15,8 +15,16 @@
 namespace DB
 {
 
+namespace ErrorCodes
+{
+    extern const int UNEXPECTED_EXPRESSION;
+}
+
 void ASTFunction::appendColumnNameImpl(WriteBuffer & ostr) const
 {
+    if (name == "view")
+        throw Exception("Table function view cannot be used as an expression", ErrorCodes::UNEXPECTED_EXPRESSION);
+
     writeString(name, ostr);
 
     if (parameters)

src/Storages/IStorage.h

@@ -12,6 +12,7 @@
 #include <Storages/StorageInMemoryMetadata.h>
 #include <Storages/ColumnDependency.h>
 #include <Storages/SelectQueryDescription.h>
+#include <Processors/QueryPipeline.h>
 #include <Common/ActionLock.h>
 #include <Common/Exception.h>
 #include <Common/RWLock.h>
@@ -34,6 +35,7 @@ class Context;
 using StorageActionBlockType = size_t;
 
 class ASTCreateQuery;
+class ASTInsertQuery;
 
 struct Settings;
 
@@ -50,6 +52,9 @@ class Pipe;
 class QueryPlan;
 using QueryPlanPtr = std::unique_ptr<QueryPlan>;
 
+class QueryPipeline;
+using QueryPipelinePtr = std::unique_ptr<QueryPipeline>;
+
 class IStoragePolicy;
 using StoragePolicyPtr = std::shared_ptr<const IStoragePolicy>;
 
@@ -319,6 +324,19 @@ public:
         throw Exception("Method write is not supported by storage " + getName(), ErrorCodes::NOT_IMPLEMENTED);
     }
 
+    /** Writes the data to a table in distributed manner.
+      * It is supposed that implementation looks into SELECT part of the query and executes distributed
+      * INSERT SELECT if it is possible with current storage as a receiver and query SELECT part as a producer.
+      *
+      * Returns query pipeline if distributed writing is possible, and nullptr otherwise.
+      */
+    virtual QueryPipelinePtr distributedWrite(
+        const ASTInsertQuery & /*query*/,
+        const Context & /*context*/)
+    {
+        return nullptr;
+    }
+
     /** Delete the table data. Called before deleting the directory with the data.
       * The method can be called only after detaching table from Context (when no queries are performed with table).
       * The table is not usable during and after call to this method.

src/Storages/PostgreSQL/PostgreSQLConnection.cpp

@@ -8,10 +8,10 @@
 #include <IO/Operators.h>
 
 
-namespace DB
+namespace postgres
 {
 
-PostgreSQLConnection::PostgreSQLConnection(
+Connection::Connection(
         const String & connection_str_,
         const String & address_)
     : connection_str(connection_str_)
@@ -20,14 +20,14 @@ PostgreSQLConnection::PostgreSQLConnection(
 }
 
 
-PostgreSQLConnection::ConnectionPtr PostgreSQLConnection::get()
+pqxx::ConnectionPtr Connection::get()
 {
     connectIfNeeded();
     return connection;
 }
 
 
-PostgreSQLConnection::ConnectionPtr PostgreSQLConnection::tryGet()
+pqxx::ConnectionPtr Connection::tryGet()
 {
     if (tryConnectIfNeeded())
         return connection;
@@ -35,7 +35,7 @@ PostgreSQLConnection::ConnectionPtr PostgreSQLConnection::tryGet()
 }
 
 
-void PostgreSQLConnection::connectIfNeeded()
+void Connection::connectIfNeeded()
 {
     if (!connection || !connection->is_open())
     {
@@ -45,7 +45,7 @@ void PostgreSQLConnection::connectIfNeeded()
 }
 
 
-bool PostgreSQLConnection::tryConnectIfNeeded()
+bool Connection::tryConnectIfNeeded()
 {
     try
     {

src/Storages/PostgreSQL/PostgreSQLConnection.h

@@ -10,24 +10,27 @@
 #include <Common/ConcurrentBoundedQueue.h>
 
 
-namespace DB
+namespace pqxx
+{
+    using ConnectionPtr = std::shared_ptr<pqxx::connection>;
+}
+
+namespace postgres
 {
 
-class PostgreSQLConnection
+class Connection
 {
 
-using ConnectionPtr = std::shared_ptr<pqxx::connection>;
-
 public:
-    PostgreSQLConnection(
+    Connection(
         const String & connection_str_,
         const String & address_);
 
-    PostgreSQLConnection(const PostgreSQLConnection & other) = delete;
+    Connection(const Connection & other) = delete;
 
-    ConnectionPtr get();
+    pqxx::ConnectionPtr get();
 
-    ConnectionPtr tryGet();
+    pqxx::ConnectionPtr tryGet();
 
     bool isConnected() { return tryConnectIfNeeded(); }
 
@@ -38,40 +41,40 @@ private:
 
     const std::string & getAddress() { return address; }
 
-    ConnectionPtr connection;
+    pqxx::ConnectionPtr connection;
     std::string connection_str, address;
 };
 
-using PostgreSQLConnectionPtr = std::shared_ptr<PostgreSQLConnection>;
+using ConnectionPtr = std::shared_ptr<Connection>;
 
 
-class PostgreSQLConnectionHolder
+class ConnectionHolder
 {
 
-using Pool = ConcurrentBoundedQueue<PostgreSQLConnectionPtr>;
+using Pool = ConcurrentBoundedQueue<ConnectionPtr>;
 static constexpr inline auto POSTGRESQL_POOL_WAIT_MS = 50;
 
 public:
-    PostgreSQLConnectionHolder(PostgreSQLConnectionPtr connection_, Pool & pool_)
+    ConnectionHolder(ConnectionPtr connection_, Pool & pool_)
         : connection(std::move(connection_))
         , pool(pool_)
     {
     }
 
-    PostgreSQLConnectionHolder(const PostgreSQLConnectionHolder & other) = delete;
+    ConnectionHolder(const ConnectionHolder & other) = delete;
 
-    ~PostgreSQLConnectionHolder() { pool.tryPush(connection, POSTGRESQL_POOL_WAIT_MS); }
+    ~ConnectionHolder() { pool.tryPush(connection, POSTGRESQL_POOL_WAIT_MS); }
 
     pqxx::connection & conn() const { return *connection->get(); }
 
     bool isConnected() { return connection->isConnected(); }
 
 private:
-    PostgreSQLConnectionPtr connection;
+    ConnectionPtr connection;
     Pool & pool;
 };
 
-using PostgreSQLConnectionHolderPtr = std::shared_ptr<PostgreSQLConnectionHolder>;
+using ConnectionHolderPtr = std::shared_ptr<ConnectionHolder>;
 
 }
 

src/Storages/PostgreSQL/PostgreSQLConnectionPool.cpp

@@ -10,10 +10,10 @@
 #include <common/logger_useful.h>
 
 
-namespace DB
+namespace postgres
 {
 
-PostgreSQLConnectionPool::PostgreSQLConnectionPool(
+ConnectionPool::ConnectionPool(
         std::string dbname,
         std::string host,
         UInt16 port,
@@ -37,7 +37,7 @@ PostgreSQLConnectionPool::PostgreSQLConnectionPool(
 }
 
 
-PostgreSQLConnectionPool::PostgreSQLConnectionPool(const PostgreSQLConnectionPool & other)
+ConnectionPool::ConnectionPool(const ConnectionPool & other)
         : pool(std::make_shared<Pool>(other.pool_size))
         , connection_str(other.connection_str)
         , address(other.address)
@@ -49,46 +49,46 @@ PostgreSQLConnectionPool::PostgreSQLConnectionPool(const PostgreSQLConnectionPoo
 }
 
 
-void PostgreSQLConnectionPool::initialize()
+void ConnectionPool::initialize()
 {
     /// No connection is made, just fill pool with non-connected connection objects.
     for (size_t i = 0; i < pool_size; ++i)
-        pool->push(std::make_shared<PostgreSQLConnection>(connection_str, address));
+        pool->push(std::make_shared<Connection>(connection_str, address));
 }
 
 
-std::string PostgreSQLConnectionPool::formatConnectionString(
+std::string ConnectionPool::formatConnectionString(
     std::string dbname, std::string host, UInt16 port, std::string user, std::string password)
 {
-    WriteBufferFromOwnString out;
-    out << "dbname=" << quote << dbname
-        << " host=" << quote << host
+    DB::WriteBufferFromOwnString out;
+    out << "dbname=" << DB::quote << dbname
+        << " host=" << DB::quote << host
         << " port=" << port
-        << " user=" << quote << user
-        << " password=" << quote << password;
+        << " user=" << DB::quote << user
+        << " password=" << DB::quote << password;
     return out.str();
 }
 
 
-PostgreSQLConnectionHolderPtr PostgreSQLConnectionPool::get()
+ConnectionHolderPtr ConnectionPool::get()
 {
-    PostgreSQLConnectionPtr connection;
+    ConnectionPtr connection;
 
     /// Always blocks by default.
     if (block_on_empty_pool)
     {
         /// pop to ConcurrentBoundedQueue will block until it is non-empty.
         pool->pop(connection);
-        return std::make_shared<PostgreSQLConnectionHolder>(connection, *pool);
+        return std::make_shared<ConnectionHolder>(connection, *pool);
     }
 
     if (pool->tryPop(connection, pool_wait_timeout))
     {
-        return std::make_shared<PostgreSQLConnectionHolder>(connection, *pool);
+        return std::make_shared<ConnectionHolder>(connection, *pool);
     }
 
-    connection = std::make_shared<PostgreSQLConnection>(connection_str, address);
-    return std::make_shared<PostgreSQLConnectionHolder>(connection, *pool);
+    connection = std::make_shared<Connection>(connection_str, address);
+    return std::make_shared<ConnectionHolder>(connection, *pool);
 }
 
 }

src/Storages/PostgreSQL/PostgreSQLConnectionPool.h

@@ -8,26 +8,25 @@
 #include "PostgreSQLConnection.h"
 
 
-namespace DB
+namespace postgres
 {
 
-class PostgreSQLReplicaConnection;
-
+class PoolWithFailover;
 
 /// Connection pool size is defined by user with setting `postgresql_connection_pool_size` (default 16).
 /// If pool is empty, it will block until there are available connections.
 /// If setting `connection_pool_wait_timeout` is defined, it will not block on empty pool and will
 /// wait until the timeout and then create a new connection. (only for storage/db engine)
-class PostgreSQLConnectionPool
+class ConnectionPool
 {
 
-friend class PostgreSQLReplicaConnection;
+friend class PoolWithFailover;
 
 static constexpr inline auto POSTGRESQL_POOL_DEFAULT_SIZE = 16;
 
 public:
 
-    PostgreSQLConnectionPool(
+    ConnectionPool(
         std::string dbname,
         std::string host,
         UInt16 port,
@@ -36,14 +35,14 @@ public:
         size_t pool_size_ = POSTGRESQL_POOL_DEFAULT_SIZE,
         int64_t pool_wait_timeout_ = -1);
 
-    PostgreSQLConnectionPool(const PostgreSQLConnectionPool & other);
+    ConnectionPool(const ConnectionPool & other);
 
-    PostgreSQLConnectionPool operator =(const PostgreSQLConnectionPool &) = delete;
+    ConnectionPool operator =(const ConnectionPool &) = delete;
 
-    PostgreSQLConnectionHolderPtr get();
+    ConnectionHolderPtr get();
 
 private:
-    using Pool = ConcurrentBoundedQueue<PostgreSQLConnectionPtr>;
+    using Pool = ConcurrentBoundedQueue<ConnectionPtr>;
     using PoolPtr = std::shared_ptr<Pool>;
 
     static std::string formatConnectionString(
@@ -58,7 +57,7 @@ private:
     bool block_on_empty_pool;
 };
 
-using PostgreSQLConnectionPoolPtr = std::shared_ptr<PostgreSQLConnectionPool>;
+using ConnectionPoolPtr = std::shared_ptr<ConnectionPool>;
 
 }
 

src/Storages/PostgreSQL/PostgreSQLPoolWithFailover.cpp

@@ -0,0 +1,110 @@
+#include "PostgreSQLPoolWithFailover.h"
+#include "PostgreSQLConnection.h"
+#include <Common/parseRemoteDescription.h>
+#include <Common/Exception.h>
+#include <common/logger_useful.h>
+
+
+namespace DB
+{
+namespace ErrorCodes
+{
+    extern const int POSTGRESQL_CONNECTION_FAILURE;
+}
+}
+
+namespace postgres
+{
+
+PoolWithFailover::PoolWithFailover(
+        const Poco::Util::AbstractConfiguration & config,
+        const std::string & config_prefix,
+        const size_t max_tries_)
+        : max_tries(max_tries_)
+{
+    auto db = config.getString(config_prefix + ".db", "");
+    auto host = config.getString(config_prefix + ".host", "");
+    auto port = config.getUInt(config_prefix + ".port", 0);
+    auto user = config.getString(config_prefix + ".user", "");
+    auto password = config.getString(config_prefix + ".password", "");
+
+    if (config.has(config_prefix + ".replica"))
+    {
+        Poco::Util::AbstractConfiguration::Keys config_keys;
+        config.keys(config_prefix, config_keys);
+
+        for (const auto & config_key : config_keys)
+        {
+            if (config_key.starts_with("replica"))
+            {
+                std::string replica_name = config_prefix + "." + config_key;
+                size_t priority = config.getInt(replica_name + ".priority", 0);
+
+                auto replica_host = config.getString(replica_name + ".host", host);
+                auto replica_port = config.getUInt(replica_name + ".port", port);
+                auto replica_user = config.getString(replica_name + ".user", user);
+                auto replica_password = config.getString(replica_name + ".password", password);
+
+                replicas_with_priority[priority].emplace_back(std::make_shared<ConnectionPool>(db, replica_host, replica_port, replica_user, replica_password));
+            }
+        }
+    }
+    else
+    {
+        replicas_with_priority[0].emplace_back(std::make_shared<ConnectionPool>(db, host, port, user, password));
+    }
+}
+
+
+PoolWithFailover::PoolWithFailover(
+        const std::string & database,
+        const RemoteDescription & addresses,
+        const std::string & user,
+        const std::string & password,
+        size_t pool_size,
+        int64_t pool_wait_timeout,
+        size_t max_tries_)
+    : max_tries(max_tries_)
+{
+    /// Replicas have the same priority, but traversed replicas are moved to the end of the queue.
+    for (const auto & [host, port] : addresses)
+    {
+        LOG_DEBUG(&Poco::Logger::get("PostgreSQLPoolWithFailover"), "Adding address host: {}, port: {} to connection pool", host, port);
+        replicas_with_priority[0].emplace_back(std::make_shared<ConnectionPool>(database, host, port, user, password, pool_size, pool_wait_timeout));
+    }
+}
+
+
+PoolWithFailover::PoolWithFailover(const PoolWithFailover & other)
+        : replicas_with_priority(other.replicas_with_priority)
+        , max_tries(other.max_tries)
+{
+}
+
+
+ConnectionHolderPtr PoolWithFailover::get()
+{
+    std::lock_guard lock(mutex);
+
+    for (size_t try_idx = 0; try_idx < max_tries; ++try_idx)
+    {
+        for (auto & priority : replicas_with_priority)
+        {
+            auto & replicas = priority.second;
+            for (size_t i = 0; i < replicas.size(); ++i)
+            {
+                auto connection = replicas[i]->get();
+                if (connection->isConnected())
+                {
+                    /// Move all traversed replicas to the end.
+                    std::rotate(replicas.begin(), replicas.begin() + i + 1, replicas.end());
+                    return connection;
+                }
+            }
+        }
+    }
+
+    throw DB::Exception(DB::ErrorCodes::POSTGRESQL_CONNECTION_FAILURE, "Unable to connect to any of the replicas");
+}
+
+}

src/Storages/PostgreSQL/PostgreSQLPoolWithFailover.h

@@ -0,0 +1,51 @@
+#pragma once
+
+#include <Core/Types.h>
+#include <Poco/Util/AbstractConfiguration.h>
+#include "PostgreSQLConnectionPool.h"
+
+
+namespace postgres
+{
+
+class PoolWithFailover
+{
+
+using RemoteDescription = std::vector<std::pair<String, uint16_t>>;
+
+public:
+    static constexpr inline auto POSTGRESQL_POOL_WITH_FAILOVER_DEFAULT_MAX_TRIES = 5;
+    static constexpr inline auto POSTGRESQL_POOL_DEFAULT_SIZE = 16;
+
+    PoolWithFailover(
+        const Poco::Util::AbstractConfiguration & config,
+        const std::string & config_prefix,
+        const size_t max_tries_ = POSTGRESQL_POOL_WITH_FAILOVER_DEFAULT_MAX_TRIES);
+
+    PoolWithFailover(
+        const std::string & database,
+        const RemoteDescription & addresses,
+        const std::string & user,
+        const std::string & password,
+        size_t pool_size = POSTGRESQL_POOL_DEFAULT_SIZE,
+        int64_t pool_wait_timeout = -1,
+        size_t max_tries_ = POSTGRESQL_POOL_WITH_FAILOVER_DEFAULT_MAX_TRIES);
+
+    PoolWithFailover(const PoolWithFailover & other);
+
+    ConnectionHolderPtr get();
+
+
+private:
+    /// Highest priority is 0, the bigger the number in map, the less the priority
+    using Replicas = std::vector<ConnectionPoolPtr>;
+    using ReplicasWithPriority = std::map<size_t, Replicas>;
+
+    ReplicasWithPriority replicas_with_priority;
+    size_t max_tries;
+    std::mutex mutex;
+};
+
+using PoolWithFailoverPtr = std::shared_ptr<PoolWithFailover>;
+
+}

src/Storages/PostgreSQL/PostgreSQLReplicaConnection.cpp

@@ -1,79 +0,0 @@
-#include "PostgreSQLReplicaConnection.h"
-#include "PostgreSQLConnection.h"
-#include <Common/Exception.h>
-
-
-namespace DB
-{
-
-namespace ErrorCodes
-{
-    extern const int POSTGRESQL_CONNECTION_FAILURE;
-}
-
-
-PostgreSQLReplicaConnection::PostgreSQLReplicaConnection(
-        const Poco::Util::AbstractConfiguration & config,
-        const String & config_prefix,
-        const size_t num_retries_)
-        : num_retries(num_retries_)
-{
-    auto db = config.getString(config_prefix + ".db", "");
-    auto host = config.getString(config_prefix + ".host", "");
-    auto port = config.getUInt(config_prefix + ".port", 0);
-    auto user = config.getString(config_prefix + ".user", "");
-    auto password = config.getString(config_prefix + ".password", "");
-
-    if (config.has(config_prefix + ".replica"))
-    {
-        Poco::Util::AbstractConfiguration::Keys config_keys;
-        config.keys(config_prefix, config_keys);
-
-        for (const auto & config_key : config_keys)
-        {
-            if (config_key.starts_with("replica"))
-            {
-                std::string replica_name = config_prefix + "." + config_key;
-                size_t priority = config.getInt(replica_name + ".priority", 0);
-
-                auto replica_host = config.getString(replica_name + ".host", host);
-                auto replica_port = config.getUInt(replica_name + ".port", port);
-                auto replica_user = config.getString(replica_name + ".user", user);
-                auto replica_password = config.getString(replica_name + ".password", password);
-
-                replicas[priority] = std::make_shared<PostgreSQLConnectionPool>(db, replica_host, replica_port, replica_user, replica_password);
-            }
-        }
-    }
-    else
-    {
-        replicas[0] = std::make_shared<PostgreSQLConnectionPool>(db, host, port, user, password);
-    }
-}
-
-
-PostgreSQLReplicaConnection::PostgreSQLReplicaConnection(const PostgreSQLReplicaConnection & other)
-        : replicas(other.replicas)
-        , num_retries(other.num_retries)
-{
-}
-
-
-PostgreSQLConnectionHolderPtr PostgreSQLReplicaConnection::get()
-{
-    std::lock_guard lock(mutex);
-
-    for (size_t i = 0; i < num_retries; ++i)
-    {
-        for (auto & replica : replicas)
-        {
-            auto connection = replica.second->get();
-            if (connection->isConnected())
-                return connection;
-        }
-    }
-
-    throw Exception(ErrorCodes::POSTGRESQL_CONNECTION_FAILURE, "Unable to connect to any of the replicas");
-}
-
-}

src/Storages/StorageDistributed.cpp

@@ -1,8 +1,11 @@
 #include <Storages/StorageDistributed.h>
 
 #include <Databases/IDatabase.h>
+
 #include <Disks/IDisk.h>
 
+#include <DataStreams/RemoteBlockInputStream.h>
+
 #include <DataTypes/DataTypeFactory.h>
 #include <DataTypes/DataTypeUUID.h>
 #include <DataTypes/DataTypesNumber.h>
@@ -31,9 +34,7 @@
 #include <Parsers/ParserAlterQuery.h>
 #include <Parsers/TablePropertiesQueriesASTs.h>
 #include <Parsers/parseQuery.h>
-
-#include <Processors/QueryPlan/BuildQueryPipelineSettings.h>
-#include <Processors/QueryPlan/Optimizations/QueryPlanOptimizationSettings.h>
+#include <Parsers/queryToString.h>
 
 #include <Interpreters/ClusterProxy/SelectStreamFactory.h>
 #include <Interpreters/ClusterProxy/executeQuery.h>
@@ -42,6 +43,7 @@
 #include <Interpreters/InterpreterAlterQuery.h>
 #include <Interpreters/InterpreterDescribeQuery.h>
 #include <Interpreters/InterpreterSelectQuery.h>
+#include <Interpreters/JoinedTables.h>
 #include <Interpreters/TranslateQualifiedNamesVisitor.h>
 #include <Interpreters/TreeRewriter.h>
 #include <Interpreters/Context.h>
@@ -51,8 +53,12 @@
 #include <Interpreters/getTableExpressions.h>
 #include <Functions/IFunction.h>
 
+#include <Processors/QueryPlan/BuildQueryPipelineSettings.h>
+#include <Processors/QueryPlan/Optimizations/QueryPlanOptimizationSettings.h>
 #include <Processors/QueryPlan/ReadFromPreparedSource.h>
 #include <Processors/Sources/NullSource.h>
+#include <Processors/Sources/SourceFromInputStream.h>
+#include <Processors/NullSink.h>
 
 #include <Core/Field.h>
 #include <Core/Settings.h>
@@ -60,6 +66,7 @@
 #include <IO/ReadHelpers.h>
 #include <IO/WriteBufferFromString.h>
 #include <IO/Operators.h>
+#include <IO/ConnectionTimeoutsContext.h>
 
 #include <Poco/DirectoryIterator.h>
 
@@ -75,6 +82,8 @@ const UInt64 FORCE_OPTIMIZE_SKIP_UNUSED_SHARDS_HAS_SHARDING_KEY = 1;
 const UInt64 FORCE_OPTIMIZE_SKIP_UNUSED_SHARDS_ALWAYS           = 2;
 
 const UInt64 DISTRIBUTED_GROUP_BY_NO_MERGE_AFTER_AGGREGATION = 2;
+
+const UInt64 PARALLEL_DISTRIBUTED_INSERT_SELECT_ALL = 2;
 }
 
 namespace ProfileEvents
@@ -613,6 +622,85 @@ BlockOutputStreamPtr StorageDistributed::write(const ASTPtr &, const StorageMeta
 }
 
 
+QueryPipelinePtr StorageDistributed::distributedWrite(const ASTInsertQuery & query, const Context & context)
+{
+    const Settings & settings = context.getSettingsRef();
+    std::shared_ptr<StorageDistributed> storage_src;
+    auto & select = query.select->as<ASTSelectWithUnionQuery &>();
+    auto new_query = std::dynamic_pointer_cast<ASTInsertQuery>(query.clone());
+    if (select.list_of_selects->children.size() == 1)
+    {
+        if (auto * select_query = select.list_of_selects->children.at(0)->as<ASTSelectQuery>())
+        {
+            JoinedTables joined_tables(Context(context), *select_query);
+
+            if (joined_tables.tablesCount() == 1)
+            {
+                storage_src = std::dynamic_pointer_cast<StorageDistributed>(joined_tables.getLeftTableStorage());
+                if (storage_src)
+                {
+                    const auto select_with_union_query = std::make_shared<ASTSelectWithUnionQuery>();
+                    select_with_union_query->list_of_selects = std::make_shared<ASTExpressionList>();
+
+                    auto new_select_query = std::dynamic_pointer_cast<ASTSelectQuery>(select_query->clone());
+                    select_with_union_query->list_of_selects->children.push_back(new_select_query);
+
+                    new_select_query->replaceDatabaseAndTable(storage_src->getRemoteDatabaseName(), storage_src->getRemoteTableName());
+
+                    new_query->select = select_with_union_query;
+                }
+            }
+        }
+    }
+
+    if (!storage_src || storage_src->getClusterName() != getClusterName())
+    {
+        return nullptr;
+    }
+
+    if (settings.parallel_distributed_insert_select == PARALLEL_DISTRIBUTED_INSERT_SELECT_ALL)
+    {
+        new_query->table_id = StorageID(getRemoteDatabaseName(), getRemoteTableName());
+    }
+
+    const auto & cluster = getCluster();
+    const auto & shards_info = cluster->getShardsInfo();
+
+    std::vector<std::unique_ptr<QueryPipeline>> pipelines;
+
+    String new_query_str = queryToString(new_query);
+    for (size_t shard_index : ext::range(0, shards_info.size()))
+    {
+        const auto & shard_info = shards_info[shard_index];
+        if (shard_info.isLocal())
+        {
+            InterpreterInsertQuery interpreter(new_query, context);
+            pipelines.emplace_back(std::make_unique<QueryPipeline>(interpreter.execute().pipeline));
+        }
+        else
+        {
+            auto timeouts = ConnectionTimeouts::getTCPTimeoutsWithFailover(settings);
+            auto connections = shard_info.pool->getMany(timeouts, &settings, PoolMode::GET_ONE);
+            if (connections.empty() || connections.front().isNull())
+                throw Exception(
+                    "Expected exactly one connection for shard " + toString(shard_info.shard_num), ErrorCodes::LOGICAL_ERROR);
+
+            ///  INSERT SELECT query returns empty block
+            auto in_stream = std::make_shared<RemoteBlockInputStream>(std::move(connections), new_query_str, Block{}, context);
+            pipelines.emplace_back(std::make_unique<QueryPipeline>());
+            pipelines.back()->init(Pipe(std::make_shared<SourceFromInputStream>(std::move(in_stream))));
+            pipelines.back()->setSinks([](const Block & header, QueryPipeline::StreamType) -> ProcessorPtr
+            {
+                return std::make_shared<EmptySink>(header);
+            });
+        }
+    }
+
+    return std::make_unique<QueryPipeline>(
+        QueryPipeline::unitePipelines(std::move(pipelines), {}, ExpressionActionsSettings::fromContext(context)));
+}
+
+
 void StorageDistributed::checkAlterIsPossible(const AlterCommands & commands, const Context & context) const
 {
     auto name_deps = getDependentViewsByColumn(context);

src/Storages/StorageDistributed.h

@@ -81,6 +81,8 @@ public:
 
     BlockOutputStreamPtr write(const ASTPtr & query, const StorageMetadataPtr & /*metadata_snapshot*/, const Context & context) override;
 
+    QueryPipelinePtr distributedWrite(const ASTInsertQuery & query, const Context & context) override;
+
     /// Removes temporary data in local filesystem.
     void truncate(const ASTPtr &, const StorageMetadataPtr &, const Context &, TableExclusiveLockHolder &) override;
 

src/Storages/StorageExternalDistributed.cpp

@@ -0,0 +1,189 @@
+#include "StorageExternalDistributed.h"
+
+#if USE_MYSQL || USE_LIBPQXX
+
+#include <Storages/StorageFactory.h>
+#include <Interpreters/evaluateConstantExpression.h>
+#include <Core/Settings.h>
+#include <Interpreters/Context.h>
+#include <DataTypes/DataTypeString.h>
+#include <Formats/FormatFactory.h>
+#include <Parsers/ASTLiteral.h>
+#include <Common/parseAddress.h>
+#include <Processors/Pipe.h>
+#include <Common/parseRemoteDescription.h>
+#include <Storages/StorageMySQL.h>
+#include <Storages/StoragePostgreSQL.h>
+#include <common/logger_useful.h>
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+    extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
+    extern const int BAD_ARGUMENTS;
+}
+
+StorageExternalDistributed::StorageExternalDistributed(
+    const StorageID & table_id_,
+    ExternalStorageEngine table_engine,
+    const String & cluster_description,
+    const String & remote_database,
+    const String & remote_table,
+    const String & username,
+    const String & password,
+    const ColumnsDescription & columns_,
+    const ConstraintsDescription & constraints_,
+    const Context & context)
+    : IStorage(table_id_)
+{
+    StorageInMemoryMetadata storage_metadata;
+    storage_metadata.setColumns(columns_);
+    storage_metadata.setConstraints(constraints_);
+    setInMemoryMetadata(storage_metadata);
+
+    size_t max_addresses = context.getSettingsRef().glob_expansion_max_elements;
+    std::vector<String> shards_descriptions = parseRemoteDescription(cluster_description, 0, cluster_description.size(), ',', max_addresses);
+    std::vector<std::pair<std::string, UInt16>> addresses;
+
+    /// For each shard pass replicas description into storage, replicas are managed by storage's PoolWithFailover.
+    for (const auto & shard_description : shards_descriptions)
+    {
+        StoragePtr shard;
+
+        switch (table_engine)
+        {
+#if USE_MYSQL
+            case ExternalStorageEngine::MySQL:
+            {
+                addresses = parseRemoteDescriptionForExternalDatabase(shard_description, max_addresses, 3306);
+
+                mysqlxx::PoolWithFailover pool(
+                    remote_database,
+                    addresses,
+                    username, password);
+
+                shard = StorageMySQL::create(
+                    table_id_,
+                    std::move(pool),
+                    remote_database,
+                    remote_table,
+                    /* replace_query = */ false,
+                    /* on_duplicate_clause = */ "",
+                    columns_, constraints_,
+                    context);
+                break;
+            }
+#endif
+#if USE_LIBPQXX
+
+            case ExternalStorageEngine::PostgreSQL:
+            {
+                addresses = parseRemoteDescriptionForExternalDatabase(shard_description, max_addresses, 5432);
+
+                postgres::PoolWithFailover pool(
+                    remote_database,
+                    addresses,
+                    username, password,
+                    context.getSettingsRef().postgresql_connection_pool_size,
+                    context.getSettingsRef().postgresql_connection_pool_wait_timeout);
+
+                shard = StoragePostgreSQL::create(
+                    table_id_,
+                    std::move(pool),
+                    remote_table,
+                    columns_, constraints_,
+                    context);
+                break;
+            }
+#endif
+            default:
+                throw Exception(ErrorCodes::BAD_ARGUMENTS,
+                    "Unsupported table engine. Supported engines are: MySQL, PostgreSQL");
+        }
+
+        shards.emplace(std::move(shard));
+    }
+}
+
+
+Pipe StorageExternalDistributed::read(
+    const Names & column_names,
+    const StorageMetadataPtr & metadata_snapshot,
+    SelectQueryInfo & query_info,
+    const Context & context,
+    QueryProcessingStage::Enum processed_stage,
+    size_t max_block_size,
+    unsigned num_streams)
+{
+    Pipes pipes;
+    for (const auto & shard : shards)
+    {
+        pipes.emplace_back(shard->read(
+            column_names,
+            metadata_snapshot,
+            query_info,
+            context,
+            processed_stage,
+            max_block_size,
+            num_streams
+        ));
+    }
+
+    return Pipe::unitePipes(std::move(pipes));
+}
+
+
+void registerStorageExternalDistributed(StorageFactory & factory)
+{
+    factory.registerStorage("ExternalDistributed", [](const StorageFactory::Arguments & args)
+    {
+        ASTs & engine_args = args.engine_args;
+
+        if (engine_args.size() != 6)
+            throw Exception(
+                "Storage MySQLiDistributed requires 5 parameters: ExternalDistributed('engine_name', 'cluster_description', database, table, 'user', 'password').",
+                ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
+        for (auto & engine_arg : engine_args)
+            engine_arg = evaluateConstantExpressionOrIdentifierAsLiteral(engine_arg, args.local_context);
+
+        const String & engine_name = engine_args[0]->as<ASTLiteral &>().value.safeGet<String>();
+        const String & cluster_description = engine_args[1]->as<ASTLiteral &>().value.safeGet<String>();
+        const String & remote_database = engine_args[2]->as<ASTLiteral &>().value.safeGet<String>();
+        const String & remote_table = engine_args[3]->as<ASTLiteral &>().value.safeGet<String>();
+        const String & username = engine_args[4]->as<ASTLiteral &>().value.safeGet<String>();
+        const String & password = engine_args[5]->as<ASTLiteral &>().value.safeGet<String>();
+
+        StorageExternalDistributed::ExternalStorageEngine table_engine;
+        if (engine_name == "MySQL")
+            table_engine = StorageExternalDistributed::ExternalStorageEngine::MySQL;
+        else if (engine_name == "PostgreSQL")
+            table_engine = StorageExternalDistributed::ExternalStorageEngine::PostgreSQL;
+        else
+            throw Exception(ErrorCodes::BAD_ARGUMENTS,
+                "External storage engine {} is not supported for StorageExternalDistributed. Supported engines are: MySQL, PostgreSQL",
+                engine_name);
+
+        return StorageExternalDistributed::create(
+            args.table_id,
+            table_engine,
+            cluster_description,
+            remote_database,
+            remote_table,
+            username,
+            password,
+            args.columns,
+            args.constraints,
+            args.context);
+    },
+    {
+        .source_access_type = AccessType::MYSQL,
+    });
+}
+
+}
+
+#endif

src/Storages/StorageExternalDistributed.h

@@ -0,0 +1,65 @@
+#pragma once
+
+#if !defined(ARCADIA_BUILD)
+#include "config_core.h"
+#endif
+
+#if USE_MYSQL || USE_LIBPQXX
+
+#include <ext/shared_ptr_helper.h>
+#include <Storages/IStorage.h>
+#include <mysqlxx/PoolWithFailover.h>
+
+
+namespace DB
+{
+
+/// Storages MySQL and PostgreSQL use ConnectionPoolWithFailover and support multiple replicas.
+/// This class unites multiple storages with replicas into multiple shards with replicas.
+/// A query to external database is passed to one replica on each shard, the result is united.
+/// Replicas on each shard have the same priority, traversed replicas are moved to the end of the queue.
+/// TODO: try `load_balancing` setting for replicas priorities same way as for table function `remote`
+class StorageExternalDistributed final : public ext::shared_ptr_helper<StorageExternalDistributed>, public DB::IStorage
+{
+    friend struct ext::shared_ptr_helper<StorageExternalDistributed>;
+
+public:
+    enum class ExternalStorageEngine
+    {
+        MySQL,
+        PostgreSQL,
+        Default
+    };
+
+    std::string getName() const override { return "ExternalDistributed"; }
+
+    Pipe read(
+        const Names & column_names,
+        const StorageMetadataPtr & /*metadata_snapshot*/,
+        SelectQueryInfo & query_info,
+        const Context & context,
+        QueryProcessingStage::Enum processed_stage,
+        size_t max_block_size,
+        unsigned num_streams) override;
+
+protected:
+    StorageExternalDistributed(
+        const StorageID & table_id_,
+        ExternalStorageEngine table_engine,
+        const String & cluster_description,
+        const String & remote_database_,
+        const String & remote_table_,
+        const String & username,
+        const String & password,
+        const ColumnsDescription & columns_,
+        const ConstraintsDescription & constraints_,
+        const Context & context_);
+
+private:
+    using Shards = std::unordered_set<StoragePtr>;
+    Shards shards;
+};
+
+}
+
+#endif

src/Storages/StorageMySQL.cpp

@@ -18,6 +18,7 @@
 #include <mysqlxx/Transaction.h>
 #include <Processors/Sources/SourceFromInputStream.h>
 #include <Processors/Pipe.h>
+#include <Common/parseRemoteDescription.h>
 
 
 namespace DB
@@ -41,7 +42,7 @@ static String backQuoteMySQL(const String & x)
 
 StorageMySQL::StorageMySQL(
     const StorageID & table_id_,
-    mysqlxx::Pool && pool_,
+    mysqlxx::PoolWithFailover && pool_,
     const std::string & remote_database_name_,
     const std::string & remote_table_name_,
     const bool replace_query_,
@@ -54,7 +55,7 @@ StorageMySQL::StorageMySQL(
     , remote_table_name(remote_table_name_)
     , replace_query{replace_query_}
     , on_duplicate_clause{on_duplicate_clause_}
-    , pool(std::move(pool_))
+    , pool(std::make_shared<mysqlxx::PoolWithFailover>(pool_))
     , global_context(context_.getGlobalContext())
 {
     StorageInMemoryMetadata storage_metadata;
@@ -94,9 +95,8 @@ Pipe StorageMySQL::read(
         sample_block.insert({ column_data.type, column_data.name });
     }
 
-    /// TODO: rewrite MySQLBlockInputStream
     return Pipe(std::make_shared<SourceFromInputStream>(
-            std::make_shared<MySQLLazyBlockInputStream>(pool, query, sample_block, max_block_size_, /* auto_close = */ true)));
+            std::make_shared<MySQLWithFailoverBlockInputStream>(pool, query, sample_block, max_block_size_, /* auto_close = */ true)));
 }
 
 
@@ -213,7 +213,7 @@ private:
 
 BlockOutputStreamPtr StorageMySQL::write(const ASTPtr & /*query*/, const StorageMetadataPtr & metadata_snapshot, const Context & context)
 {
-    return std::make_shared<StorageMySQLBlockOutputStream>(*this, metadata_snapshot, remote_database_name, remote_table_name, pool.get(), context.getSettingsRef().mysql_max_rows_to_insert);
+    return std::make_shared<StorageMySQLBlockOutputStream>(*this, metadata_snapshot, remote_database_name, remote_table_name, pool->get(), context.getSettingsRef().mysql_max_rows_to_insert);
 }
 
 void registerStorageMySQL(StorageFactory & factory)
@@ -224,21 +224,22 @@ void registerStorageMySQL(StorageFactory & factory)
 
         if (engine_args.size() < 5 || engine_args.size() > 7)
             throw Exception(
-                "Storage MySQL requires 5-7 parameters: MySQL('host:port', database, table, 'user', 'password'[, replace_query, 'on_duplicate_clause']).",
+                "Storage MySQL requires 5-7 parameters: MySQL('host:port' (or 'addresses_pattern'), database, table, 'user', 'password'[, replace_query, 'on_duplicate_clause']).",
                 ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
 
         for (auto & engine_arg : engine_args)
             engine_arg = evaluateConstantExpressionOrIdentifierAsLiteral(engine_arg, args.local_context);
 
         /// 3306 is the default MySQL port.
-        auto parsed_host_port = parseAddress(engine_args[0]->as<ASTLiteral &>().value.safeGet<String>(), 3306);
-
+        const String & host_port = engine_args[0]->as<ASTLiteral &>().value.safeGet<String>();
         const String & remote_database = engine_args[1]->as<ASTLiteral &>().value.safeGet<String>();
         const String & remote_table = engine_args[2]->as<ASTLiteral &>().value.safeGet<String>();
         const String & username = engine_args[3]->as<ASTLiteral &>().value.safeGet<String>();
         const String & password = engine_args[4]->as<ASTLiteral &>().value.safeGet<String>();
+        size_t max_addresses = args.context.getSettingsRef().glob_expansion_max_elements;
 
-        mysqlxx::Pool pool(remote_database, parsed_host_port.first, username, password, parsed_host_port.second);
+        auto addresses = parseRemoteDescriptionForExternalDatabase(host_port, max_addresses, 3306);
+        mysqlxx::PoolWithFailover pool(remote_database, addresses, username, password);
 
         bool replace_query = false;
         std::string on_duplicate_clause;

src/Storages/StorageMySQL.h

@@ -1,15 +1,15 @@
 #pragma once
 
 #if !defined(ARCADIA_BUILD)
-#    include "config_core.h"
+#include "config_core.h"
 #endif
 
 #if USE_MYSQL
 
-#    include <ext/shared_ptr_helper.h>
+#include <ext/shared_ptr_helper.h>
 
-#    include <Storages/IStorage.h>
-#    include <mysqlxx/Pool.h>
+#include <Storages/IStorage.h>
+#include <mysqlxx/PoolWithFailover.h>
 
 
 namespace DB
@@ -25,7 +25,7 @@ class StorageMySQL final : public ext::shared_ptr_helper<StorageMySQL>, public I
 public:
     StorageMySQL(
         const StorageID & table_id_,
-        mysqlxx::Pool && pool_,
+        mysqlxx::PoolWithFailover && pool_,
         const std::string & remote_database_name_,
         const std::string & remote_table_name_,
         const bool replace_query_,
@@ -55,7 +55,7 @@ private:
     bool replace_query;
     std::string on_duplicate_clause;
 
-    mysqlxx::Pool pool;
+    mysqlxx::PoolWithFailoverPtr pool;
     const Context & global_context;
 };
 

src/Storages/StoragePostgreSQL.cpp

@@ -26,6 +26,7 @@
 #include <Formats/FormatFactory.h>
 #include <Formats/FormatSettings.h>
 #include <Processors/Sources/SourceFromInputStream.h>
+#include <Common/parseRemoteDescription.h>
 #include <Processors/Pipe.h>
 #include <IO/WriteHelpers.h>
 
@@ -41,8 +42,8 @@ namespace ErrorCodes
 
 StoragePostgreSQL::StoragePostgreSQL(
     const StorageID & table_id_,
+    const postgres::PoolWithFailover & pool_,
     const String & remote_table_name_,
-    PostgreSQLConnectionPoolPtr connection_pool_,
     const ColumnsDescription & columns_,
     const ConstraintsDescription & constraints_,
     const Context & context_,
@@ -51,7 +52,7 @@ StoragePostgreSQL::StoragePostgreSQL(
     , remote_table_name(remote_table_name_)
     , remote_table_schema(remote_table_schema_)
     , global_context(context_)
-    , connection_pool(std::move(connection_pool_))
+    , pool(std::make_shared<postgres::PoolWithFailover>(pool_))
 {
     StorageInMemoryMetadata storage_metadata;
     storage_metadata.setColumns(columns_);
@@ -88,7 +89,7 @@ Pipe StoragePostgreSQL::read(
     }
 
     return Pipe(std::make_shared<SourceFromInputStream>(
-            std::make_shared<PostgreSQLBlockInputStream>(connection_pool->get(), query, sample_block, max_block_size_)));
+            std::make_shared<PostgreSQLBlockInputStream>(pool->get(), query, sample_block, max_block_size_)));
 }
 
 
@@ -97,7 +98,7 @@ class PostgreSQLBlockOutputStream : public IBlockOutputStream
 public:
     explicit PostgreSQLBlockOutputStream(
         const StorageMetadataPtr & metadata_snapshot_,
-        PostgreSQLConnectionHolderPtr connection_,
+        postgres::ConnectionHolderPtr connection_,
         const std::string & remote_table_name_)
         : metadata_snapshot(metadata_snapshot_)
         , connection(std::move(connection_))
@@ -276,7 +277,7 @@ public:
 
 private:
     StorageMetadataPtr metadata_snapshot;
-    PostgreSQLConnectionHolderPtr connection;
+    postgres::ConnectionHolderPtr connection;
     std::string remote_table_name;
 
     std::unique_ptr<pqxx::work> work;
@@ -287,7 +288,7 @@ private:
 BlockOutputStreamPtr StoragePostgreSQL::write(
         const ASTPtr & /*query*/, const StorageMetadataPtr & metadata_snapshot, const Context & /* context */)
 {
-    return std::make_shared<PostgreSQLBlockOutputStream>(metadata_snapshot, connection_pool->get(), remote_table_name);
+    return std::make_shared<PostgreSQLBlockOutputStream>(metadata_snapshot, pool->get(), remote_table_name);
 }
 
 
@@ -305,24 +306,31 @@ void registerStoragePostgreSQL(StorageFactory & factory)
         for (auto & engine_arg : engine_args)
             engine_arg = evaluateConstantExpressionOrIdentifierAsLiteral(engine_arg, args.local_context);
 
-        auto parsed_host_port = parseAddress(engine_args[0]->as<ASTLiteral &>().value.safeGet<String>(), 5432);
+        auto host_port = engine_args[0]->as<ASTLiteral &>().value.safeGet<String>();
+        /// Split into replicas if needed.
+        size_t max_addresses = args.context.getSettingsRef().glob_expansion_max_elements;
+        auto addresses = parseRemoteDescriptionForExternalDatabase(host_port, max_addresses, 5432);
+
+        const String & remote_database = engine_args[1]->as<ASTLiteral &>().value.safeGet<String>();
         const String & remote_table = engine_args[2]->as<ASTLiteral &>().value.safeGet<String>();
+        const String & username = engine_args[3]->as<ASTLiteral &>().value.safeGet<String>();
+        const String & password = engine_args[4]->as<ASTLiteral &>().value.safeGet<String>();
 
         String remote_table_schema;
         if (engine_args.size() == 6)
             remote_table_schema = engine_args[5]->as<ASTLiteral &>().value.safeGet<String>();
 
-        auto connection_pool = std::make_shared<PostgreSQLConnectionPool>(
-            engine_args[1]->as<ASTLiteral &>().value.safeGet<String>(),
-            parsed_host_port.first,
-            parsed_host_port.second,
-            engine_args[3]->as<ASTLiteral &>().value.safeGet<String>(),
-            engine_args[4]->as<ASTLiteral &>().value.safeGet<String>(),
+        postgres::PoolWithFailover pool(
+            remote_database,
+            addresses,
+            username,
+            password,
             args.context.getSettingsRef().postgresql_connection_pool_size,
             args.context.getSettingsRef().postgresql_connection_pool_wait_timeout);
 
         return StoragePostgreSQL::create(
-            args.table_id, remote_table, connection_pool, args.columns, args.constraints, args.context, remote_table_schema);
+            args.table_id, pool, remote_table,
+            args.columns, args.constraints, args.context, remote_table_schema);
     },
     {
         .source_access_type = AccessType::POSTGRES,

src/Storages/StoragePostgreSQL.h

@@ -9,7 +9,7 @@
 #include <Interpreters/Context.h>
 #include <Storages/IStorage.h>
 #include <DataStreams/IBlockOutputStream.h>
-#include <Storages/PostgreSQL/PostgreSQLConnectionPool.h>
+#include <Storages/PostgreSQL/PostgreSQLPoolWithFailover.h>
 #include <pqxx/pqxx>
 
 
@@ -23,8 +23,8 @@ class StoragePostgreSQL final : public ext::shared_ptr_helper<StoragePostgreSQL>
 public:
     StoragePostgreSQL(
         const StorageID & table_id_,
+        const postgres::PoolWithFailover & pool_,
         const String & remote_table_name_,
-        PostgreSQLConnectionPoolPtr connection_pool_,
         const ColumnsDescription & columns_,
         const ConstraintsDescription & constraints_,
         const Context & context_,
@@ -49,7 +49,7 @@ private:
     String remote_table_name;
     String remote_table_schema;
     Context global_context;
-    PostgreSQLConnectionPoolPtr connection_pool;
+    postgres::PoolWithFailoverPtr pool;
 };
 
 }

src/Storages/StorageReplicatedMergeTree.cpp

@@ -455,12 +455,12 @@ void StorageReplicatedMergeTree::waitMutationToFinishOnReplicas(
     if (replicas.empty())
         return;
 
-    zkutil::EventPtr wait_event = std::make_shared<Poco::Event>();
 
     std::set<String> inactive_replicas;
     for (const String & replica : replicas)
     {
         LOG_DEBUG(log, "Waiting for {} to apply mutation {}", replica, mutation_id);
+        zkutil::EventPtr wait_event = std::make_shared<Poco::Event>();
 
         while (!partial_shutdown_called)
         {
@@ -484,9 +484,8 @@ void StorageReplicatedMergeTree::waitMutationToFinishOnReplicas(
 
             String mutation_pointer = zookeeper_path + "/replicas/" + replica + "/mutation_pointer";
             std::string mutation_pointer_value;
-            Coordination::Stat get_stat;
             /// Replica could be removed
-            if (!zookeeper->tryGet(mutation_pointer, mutation_pointer_value, &get_stat, wait_event))
+            if (!zookeeper->tryGet(mutation_pointer, mutation_pointer_value, nullptr, wait_event))
             {
                 LOG_WARNING(log, "Replica {} was removed", replica);
                 break;
@@ -496,8 +495,10 @@ void StorageReplicatedMergeTree::waitMutationToFinishOnReplicas(
 
             /// Replica can become inactive, so wait with timeout and recheck it
             if (wait_event->tryWait(1000))
-                break;
+                continue;
 
+            /// Here we check mutation for errors or kill on local replica. If they happen on this replica
+            /// they will happen on each replica, so we can check only in-memory info.
             auto mutation_status = queue.getIncompleteMutationsStatus(mutation_id);
             if (!mutation_status || !mutation_status->latest_fail_reason.empty())
                 break;
@@ -514,6 +515,8 @@ void StorageReplicatedMergeTree::waitMutationToFinishOnReplicas(
         std::set<String> mutation_ids;
         mutation_ids.insert(mutation_id);
 
+        /// Here we check mutation for errors or kill on local replica. If they happen on this replica
+        /// they will happen on each replica, so we can check only in-memory info.
         auto mutation_status = queue.getIncompleteMutationsStatus(mutation_id, &mutation_ids);
         checkMutationStatus(mutation_status, mutation_ids);
 

src/Storages/StorageXDBC.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <Storages/StorageURL.h>
-#include <Common/XDBCBridgeHelper.h>
+#include <Bridge/XDBCBridgeHelper.h>
 
 
 namespace DB