Merge branch 'master' of https://github.com/yandex/ClickHouse into CLICKHOUSE-2720

CHANGELOG.draft.md

@@ -0,0 +1,11 @@
+en:
+
+## Improvements:
+* `clickhouse-client`: option --ask-password for interactively ask for credentials #1044
+
+
+
+ru:
+
+## Улучшения:
+* `clickhouse-client`: опция --ask-password для интерактивного ввода пароля #1044

CHANGELOG.md

@@ -1,3 +1,8 @@
+# ClickHouse release 1.1.54383, 2018-05-22
+
+## Bug fixes:
+* Fixed a slowdown of replication queue if a table has many replicas.
+
 # ClickHouse release 1.1.54381, 2018-05-14
 
 ## Bug fixes:

CHANGELOG_RU.md

@@ -1,3 +1,7 @@
+# ClickHouse release 1.1.54383, 2018-05-22
+## Исправление ошибок:
+* Исправлена деградация скорости выполнения очереди репликации при большом количестве реплик
+
 # ClickHouse release 1.1.54381, 2018-05-14
 
 ## Исправление ошибок:

CMakeLists.txt

@@ -128,14 +128,14 @@ endif ()
 #endif ()
 
 if (CMAKE_VERSION VERSION_LESS "3.8.0")
-    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++1z")
+    if (NOT MSVC)
+        set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++1z")
+    endif ()
 else ()
     set (CMAKE_CXX_STANDARD 17)
     set (CMAKE_CXX_EXTENSIONS 0) # https://cmake.org/cmake/help/latest/prop_tgt/CXX_EXTENSIONS.html#prop_tgt:CXX_EXTENSIONS
     set (CMAKE_CXX_STANDARD_REQUIRED ON)
     set (CXX_FLAGS_INTERNAL_COMPILER "-std=c++1z")
-    # This needs to propagate to vendored projects in contrib
-    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17")
 endif ()
 
 set (CMAKE_BUILD_COLOR_MAKEFILE          ON)

ci/build-clang-from-sources.sh

@@ -23,10 +23,10 @@ cd "${WORKSPACE}/llvm/build"
 
 # NOTE You must build LLVM with the same ABI as ClickHouse.
 # For example, if you compile ClickHouse with libc++, you must add
-#  -D LLVM_ENABLE_LIBCXX=1
+#  -DLLVM_ENABLE_LIBCXX=1
 # to the line below.
 
-cmake -D CMAKE_BUILD_TYPE:STRING=Release ../llvm
+cmake -DCMAKE_BUILD_TYPE:STRING=Release ../llvm
 
 make -j $THREADS
 $SUDO make install

ci/build-normal.sh

@@ -9,11 +9,11 @@ mkdir -p "${WORKSPACE}/build"
 pushd "${WORKSPACE}/build"
 
 if [[ "${ENABLE_EMBEDDED_COMPILER}" == 1 ]]; then
-    [[ "$USE_LLVM_LIBRARIES_FROM_SYSTEM" == 0 ]] && CMAKE_FLAGS="$CMAKE_FLAGS -D USE_INTERNAL_LLVM_LIBRARY=1"
-    [[ "$USE_LLVM_LIBRARIES_FROM_SYSTEM" != 0 ]] && CMAKE_FLAGS="$CMAKE_FLAGS -D USE_INTERNAL_LLVM_LIBRARY=0"
+    [[ "$USE_LLVM_LIBRARIES_FROM_SYSTEM" == 0 ]] && CMAKE_FLAGS="$CMAKE_FLAGS -DUSE_INTERNAL_LLVM_LIBRARY=1"
+    [[ "$USE_LLVM_LIBRARIES_FROM_SYSTEM" != 0 ]] && CMAKE_FLAGS="$CMAKE_FLAGS -DUSE_INTERNAL_LLVM_LIBRARY=0"
 fi
 
-cmake -D CMAKE_BUILD_TYPE=${BUILD_TYPE} -D ENABLE_EMBEDDED_COMPILER=${ENABLE_EMBEDDED_COMPILER} $CMAKE_FLAGS ../sources
+cmake -DCMAKE_BUILD_TYPE=${BUILD_TYPE} -DENABLE_EMBEDDED_COMPILER=${ENABLE_EMBEDDED_COMPILER} $CMAKE_FLAGS ../sources
 
 [[ "$BUILD_TARGETS" != 'all' ]] && BUILD_TARGETS_STRING="--target $BUILD_TARGETS"
 

ci/check-syntax.sh

@@ -10,7 +10,7 @@ source default-config
 mkdir -p "${WORKSPACE}/build"
 pushd "${WORKSPACE}/build"
 
-cmake -D CMAKE_BUILD_TYPE=Debug $CMAKE_FLAGS ../sources
+cmake -DCMAKE_BUILD_TYPE=Debug $CMAKE_FLAGS ../sources
 
 make -j $THREADS re2_st # Generated headers
 

cmake/find_llvm.cmake

@@ -1,4 +1,4 @@
-option (ENABLE_EMBEDDED_COMPILER "Set to TRUE to enable support for 'compile' option for query execution" 1)
+option (ENABLE_EMBEDDED_COMPILER "Set to TRUE to enable support for 'compile' option for query execution" 0)
 option (USE_INTERNAL_LLVM_LIBRARY "Use bundled or system LLVM library. Default: system library for quicker developer builds." ${APPLE})
 
 if (ENABLE_EMBEDDED_COMPILER)

cmake/find_poco.cmake

@@ -60,7 +60,6 @@ elseif (NOT MISSING_INTERNAL_POCO_LIBRARY)
     )
 
     if (NOT DEFINED ENABLE_POCO_MONGODB OR ENABLE_POCO_MONGODB)
-        set (USE_POCO_MONGODB 1)
         set (Poco_MongoDB_LIBRARY PocoMongoDB)
         set (Poco_MongoDB_INCLUDE_DIRS "${ClickHouse_SOURCE_DIR}/contrib/poco/MongoDB/include/")
     endif ()
@@ -73,7 +72,6 @@ elseif (NOT MISSING_INTERNAL_POCO_LIBRARY)
              "${ClickHouse_SOURCE_DIR}/contrib/poco/Data/include"
              )
         if ((NOT DEFINED ENABLE_POCO_ODBC OR ENABLE_POCO_ODBC) AND ODBC_FOUND)
-            set (USE_POCO_SQLODBC 1)
             set (Poco_SQLODBC_INCLUDE_DIRS
                 "${ClickHouse_SOURCE_DIR}/contrib/poco/SQL/ODBC/include/"
                 "${ClickHouse_SOURCE_DIR}/contrib/poco/Data/ODBC/include/"
@@ -97,7 +95,6 @@ elseif (NOT MISSING_INTERNAL_POCO_LIBRARY)
 
     # TODO! fix internal ssl
     if (OPENSSL_FOUND AND NOT USE_INTERNAL_SSL_LIBRARY AND (NOT DEFINED ENABLE_POCO_NETSSL OR ENABLE_POCO_NETSSL))
-        set (USE_POCO_NETSSL 1)
         set (Poco_NetSSL_LIBRARY PocoNetSSL)
         set (Poco_Crypto_LIBRARY PocoCrypto)
     endif ()
@@ -115,7 +112,20 @@ elseif (NOT MISSING_INTERNAL_POCO_LIBRARY)
     set (Poco_XML_LIBRARY PocoXML)
 endif ()
 
-message(STATUS "Using Poco: ${Poco_INCLUDE_DIRS} : ${Poco_Foundation_LIBRARY},${Poco_Util_LIBRARY},${Poco_Net_LIBRARY},${Poco_NetSSL_LIBRARY},${Poco_XML_LIBRARY},${Poco_Data_LIBRARY},${Poco_DataODBC_LIBRARY},${Poco_MongoDB_LIBRARY}; MongoDB=${USE_POCO_MONGODB}, DataODBC=${Poco_DataODBC_FOUND}, NetSSL=${USE_POCO_NETSSL}")
+if (Poco_NetSSL_LIBRARY AND Poco_Crypto_LIBRARY)
+    set (USE_POCO_NETSSL 1)
+endif ()
+if (Poco_MongoDB_LIBRARY)
+    set (USE_POCO_MONGODB 1)
+endif ()
+if (Poco_DataODBC_LIBRARY)
+    set (USE_POCO_DATAODBC 1)
+endif ()
+if (Poco_SQLODBC_LIBRARY)
+    set (USE_POCO_SQLODBC 1)
+endif ()
+
+message(STATUS "Using Poco: ${Poco_INCLUDE_DIRS} : ${Poco_Foundation_LIBRARY},${Poco_Util_LIBRARY},${Poco_Net_LIBRARY},${Poco_NetSSL_LIBRARY},${Poco_Crypto_LIBRARY},${Poco_XML_LIBRARY},${Poco_Data_LIBRARY},${Poco_DataODBC_LIBRARY},${Poco_SQL_LIBRARY},${Poco_SQLODBC_LIBRARY},${Poco_MongoDB_LIBRARY}; MongoDB=${USE_POCO_MONGODB}, DataODBC=${USE_POCO_DATAODBC}, NetSSL=${USE_POCO_NETSSL}")
 
 # How to make sutable poco:
 # use branch:

contrib/CMakeLists.txt

@@ -1,5 +1,5 @@
 if (NOT MSVC)
-    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-old-style-cast")
+    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-old-style-cast -std=c++1z")
 endif ()
 
 if (USE_INTERNAL_BOOST_LIBRARY)

contrib/libcityhash/src/config.h

@@ -116,3 +116,10 @@
 /* Define to the type of an unsigned integer type of width exactly 8 bits if
    such a type exists and the standard includes do not define it. */
 /* #undef uint8_t */
+
+#ifdef _MSC_VER
+    #include <basetsd.h>
+    typedef SSIZE_T ssize_t;
+#else
+    #include <sys/types.h>
+#endif

copy_headers.sh

@@ -17,7 +17,7 @@
 
 SOURCE_PATH=${1:-.}
 DST=${2:-$SOURCE_PATH/../headers}
-BUILD_PATH=${3:-$SOURCE_PATH/build}
+BUILD_PATH=${BUILD_PATH=${3:-$SOURCE_PATH/build}}
 
 PATH="/usr/local/bin:/usr/local/sbin:/usr/bin:$PATH"
 
@@ -30,23 +30,29 @@ START_HEADERS=$(echo \
     $SOURCE_PATH/dbms/src/Interpreters/SpecializedAggregator.h \
     $SOURCE_PATH/dbms/src/AggregateFunctions/AggregateFunction*.h)
 
+for header in $START_HEADERS; do
+    START_HEADERS_INCLUDE+="-include $header "
+done
+
 # Опция -mcx16 для того, чтобы выбиралось больше заголовочных файлов (с запасом).
 # The latter options are the same that are added while building packages.
 
+# TODO: Does not work on macos:
 GCC_ROOT=`$CLANG -v 2>&1 | grep "Selected GCC installation"| sed -n -e 's/^.*: //p'`
 
 for src_file in $(echo | $CLANG -M -xc++ -std=c++1z -Wall -Werror -msse4 -mcx16 -mpopcnt -O3 -g -fPIC -fstack-protector -D_FORTIFY_SOURCE=2 \
     -I $GCC_ROOT/include \
     -I $GCC_ROOT/include-fixed \
     $(cat "$BUILD_PATH/include_directories.txt") \
-    $(echo $START_HEADERS | sed -r -e 's/[^ ]+/-include \0/g') \
+    $START_HEADERS_INCLUDE \
     - |
     tr -d '\\' |
-    sed -r -e 's/^-\.o://');
+    sed -E -e 's/^-\.o://');
 do
     dst_file=$src_file;
-    dst_file=$(echo $dst_file | sed -r -e 's/build\///')    # for simplicity reasons, will put generated headers near the rest.
-    mkdir -p "$DST/$(echo $dst_file | sed -r -e 's/\/[^/]*$/\//')";
+    [ -n $DESTDIR ] && dst_file=$(echo $dst_file | sed -E -e "s!^$DESTDIR!!")
+    dst_file=$(echo $dst_file | sed -E -e 's/build\///')    # for simplicity reasons, will put generated headers near the rest.
+    mkdir -p "$DST/$(echo $dst_file | sed -E -e 's/\/[^/]*$/\//')";
     cp "$src_file" "$DST/$dst_file";
 done
 
@@ -56,19 +62,25 @@ done
 
 for src_file in $(ls -1 $($CLANG -v -xc++ - <<<'' 2>&1 | grep '^ /' | grep 'include' | grep -E '/lib/clang/|/include/clang/')/*.h | grep -vE 'arm|altivec|Intrin');
 do
-    mkdir -p "$DST/$(echo $src_file | sed -r -e 's/\/[^/]*$/\//')";
-    cp "$src_file" "$DST/$src_file";
+    dst_file=$src_file;
+    [ -n $DESTDIR ] && dst_file=$(echo $dst_file | sed -E -e "s!^$DESTDIR!!")
+    mkdir -p "$DST/$(echo $dst_file | sed -E -e 's/\/[^/]*$/\//')";
+    cp "$src_file" "$DST/$dst_file";
 done
 
 # Even more platform-specific headers
 for src_file in $(ls -1 $SOURCE_PATH/contrib/boost/libs/smart_ptr/include/boost/smart_ptr/detail/*);
 do
-    mkdir -p "$DST/$(echo $src_file | sed -r -e 's/\/[^/]*$/\//')";
-    cp "$src_file" "$DST/$src_file";
+    dst_file=$src_file;
+    [ -n $DESTDIR ] && dst_file=$(echo $dst_file | sed -E -e "s!^$DESTDIR!!")
+    mkdir -p "$DST/$(echo $dst_file | sed -E -e 's/\/[^/]*$/\//')";
+    cp "$src_file" "$DST/$dst_file";
 done
 
 for src_file in $(ls -1 $SOURCE_PATH/contrib/boost/boost/smart_ptr/detail/*);
 do
-    mkdir -p "$DST/$(echo $src_file | sed -r -e 's/\/[^/]*$/\//')";
-    cp "$src_file" "$DST/$src_file";
+    dst_file=$src_file;
+    [ -n $DESTDIR ] && dst_file=$(echo $dst_file | sed -E -e "s!^$DESTDIR!!")
+    mkdir -p "$DST/$(echo $dst_file | sed -E -e 's/\/[^/]*$/\//')";
+    cp "$src_file" "$DST/$dst_file";
 done

dbms/CMakeLists.txt

@@ -198,7 +198,7 @@ if (USE_POCO_MONGODB)
 endif()
 
 if (USE_POCO_NETSSL)
-    target_link_libraries (clickhouse_common_io ${Poco_NetSSL_LIBRARY})
+    target_link_libraries (clickhouse_common_io ${Poco_NetSSL_LIBRARY} ${Poco_Crypto_LIBRARY})
 endif()
 
 target_link_libraries (dbms ${Poco_Foundation_LIBRARY})
@@ -245,6 +245,12 @@ target_include_directories (clickhouse_common_io BEFORE PUBLIC ${DOUBLE_CONVERSI
 # also for copy_headers.sh:
 target_include_directories (clickhouse_common_io BEFORE PRIVATE ${COMMON_INCLUDE_DIR})
 
+if (USE_EMBEDDED_COMPILER)
+    add_custom_target(copy-headers ALL env CLANG=${CMAKE_CURRENT_BINARY_DIR}/src/Server/clickhouse-clang BUILD_PATH=${ClickHouse_BINARY_DIR} DESTDIR=${ClickHouse_SOURCE_DIR} ${ClickHouse_SOURCE_DIR}/copy_headers.sh ${ClickHouse_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR}/headers DEPENDS clickhouse-clang WORKING_DIRECTORY ${ClickHouse_SOURCE_DIR} SOURCES ${ClickHouse_SOURCE_DIR}/copy_headers.sh)
+    install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/headers DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/clickhouse COMPONENT clickhouse)
+    add_dependencies(clickhouse-bundle copy-headers)
+endif ()
+
 add_subdirectory (tests)
 
 if (ENABLE_TESTS)

dbms/src/Common/ActionBlocker.h

@@ -1,6 +1,8 @@
 #pragma once
 
 #include <atomic>
+#include <memory>
+#include <Common/ActionLock.h>
 
 namespace DB
 {
@@ -10,54 +12,25 @@ namespace DB
 class ActionBlocker
 {
 private:
-    mutable std::atomic<int> counter{0};
+    using Counter = std::atomic<int>;
+    using CounterPtr = std::shared_ptr<Counter>;
+
+    mutable CounterPtr counter;
 
 public:
-    bool isCancelled() const { return counter > 0; }
+    ActionBlocker() : counter(std::make_shared<Counter>(0)) {}
+
+    bool isCancelled() const { return *counter > 0; }
 
     /// Temporarily blocks corresponding actions (while the returned object is alive)
-    struct LockHolder;
-    LockHolder cancel() const { return LockHolder(this); }
+    friend class ActionLock;
+    ActionLock cancel() const { return ActionLock(*this); }
 
     /// Cancel the actions forever.
-    void cancelForever() const { ++counter; }
+    void cancelForever() const { ++(*counter); }
 
     /// Returns reference to counter to allow to watch on it directly.
-    auto & getCounter() { return counter; }
-
-    /// Blocks related action while a BlockerHolder instance exists
-    struct LockHolder
-    {
-        explicit LockHolder(const ActionBlocker * var_ = nullptr) : var(var_)
-        {
-            if (var)
-                ++var->counter;
-        }
-
-        LockHolder(LockHolder && other) noexcept
-        {
-            *this = std::move(other);
-        }
-
-        LockHolder & operator=(LockHolder && other) noexcept
-        {
-            var = other.var;
-            other.var = nullptr;
-            return *this;
-        }
-
-        LockHolder(const LockHolder & other) = delete;
-        LockHolder & operator=(const LockHolder & other) = delete;
-
-        ~LockHolder()
-        {
-            if (var)
-                --var->counter;
-        }
-
-    private:
-        const ActionBlocker * var = nullptr;
-    };
+    auto & getCounter() { return *counter; }
 };
 
 }

dbms/src/Common/ActionLock.cpp

@@ -0,0 +1,33 @@
+#include "ActionLock.h"
+#include <Common/ActionBlocker.h>
+
+
+namespace DB
+{
+
+ActionLock::ActionLock(const ActionBlocker & blocker) : counter_ptr(blocker.counter)
+{
+    if (auto counter = counter_ptr.lock())
+        ++(*counter);
+}
+
+ActionLock::ActionLock(ActionLock && other)
+{
+    *this = std::move(other);
+}
+
+ActionLock & ActionLock::operator=(ActionLock && other)
+{
+    auto lock_lhs = this->counter_ptr.lock();
+
+    counter_ptr = std::move(other.counter_ptr);
+    /// After move other.counter_ptr still points to counter, reset it explicitly
+    other.counter_ptr.reset();
+
+    if (lock_lhs)
+        --(*lock_lhs);
+
+    return *this;
+}
+
+}

dbms/src/Common/ActionLock.h

@@ -0,0 +1,46 @@
+#pragma once
+#include <memory>
+#include <atomic>
+#include <Core/Types.h>
+
+namespace DB
+{
+
+class ActionBlocker;
+using StorageActionBlockType = size_t;
+
+/// Blocks related action while a ActionLock instance exists
+/// ActionBlocker could be destroyed before the lock, in this case ActionLock will safely do nothing in its destructor
+class ActionLock
+{
+public:
+
+    ActionLock() = default;
+
+    explicit ActionLock(const ActionBlocker & blocker);
+
+    ActionLock(ActionLock && other);
+    ActionLock & operator=(ActionLock && other);
+
+    ActionLock(const ActionLock & other) = delete;
+    ActionLock & operator=(const ActionLock & other) = delete;
+
+    bool expired() const
+    {
+        return counter_ptr.expired();
+    }
+
+    ~ActionLock()
+    {
+        if (auto counter = counter_ptr.lock())
+            --(*counter);
+    }
+
+private:
+    using Counter = std::atomic<int>;
+    using CounterWeakPtr = std::weak_ptr<Counter>;
+
+    CounterWeakPtr counter_ptr;
+};
+
+}

dbms/src/Common/BackgroundSchedulePool.cpp

@@ -0,0 +1,300 @@
+#include <Common/BackgroundSchedulePool.h>
+#include <Common/MemoryTracker.h>
+#include <Common/CurrentMetrics.h>
+#include <Common/Exception.h>
+#include <Common/setThreadName.h>
+#include <Common/Stopwatch.h>
+#include <common/logger_useful.h>
+#include <chrono>
+
+namespace CurrentMetrics
+{
+    extern const Metric BackgroundSchedulePoolTask;
+    extern const Metric MemoryTrackingInBackgroundSchedulePool;
+}
+
+namespace DB
+{
+
+
+// TaskNotification
+
+class TaskNotification final : public Poco::Notification
+{
+public:
+    explicit TaskNotification(const BackgroundSchedulePool::TaskHandle & task) : task(task) {}
+    void execute() { task->execute(); }
+
+private:
+    BackgroundSchedulePool::TaskHandle task;
+};
+
+
+// BackgroundSchedulePool::TaskInfo
+
+BackgroundSchedulePool::TaskInfo::TaskInfo(BackgroundSchedulePool & pool, const std::string & name, const Task & function):
+    name(name),
+    pool(pool),
+    function(function)
+{
+}
+
+
+bool BackgroundSchedulePool::TaskInfo::schedule()
+{
+    std::lock_guard lock(schedule_mutex);
+
+    if (deactivated || scheduled)
+        return false;
+
+    scheduled = true;
+
+    if (!executing)
+    {
+        if (delayed)
+            pool.cancelDelayedTask(shared_from_this(), lock);
+
+        pool.queue.enqueueNotification(new TaskNotification(shared_from_this()));
+    }
+
+    return true;
+}
+
+
+bool BackgroundSchedulePool::TaskInfo::scheduleAfter(size_t ms)
+{
+    std::lock_guard lock(schedule_mutex);
+
+    if (deactivated || scheduled)
+        return false;
+
+    pool.scheduleDelayedTask(shared_from_this(), ms, lock);
+    return true;
+}
+
+
+void BackgroundSchedulePool::TaskInfo::deactivate()
+{
+    std::lock_guard lock_exec(exec_mutex);
+    std::lock_guard lock_schedule(schedule_mutex);
+
+    if (deactivated)
+        return;
+
+    deactivated = true;
+    scheduled = false;
+
+    if (delayed)
+        pool.cancelDelayedTask(shared_from_this(), lock_schedule);
+}
+
+
+void BackgroundSchedulePool::TaskInfo::activate()
+{
+    std::lock_guard lock(schedule_mutex);
+    deactivated = false;
+}
+
+
+void BackgroundSchedulePool::TaskInfo::execute()
+{
+    std::lock_guard lock_exec(exec_mutex);
+
+    {
+        std::lock_guard lock_schedule(schedule_mutex);
+
+        if (deactivated)
+            return;
+
+        scheduled = false;
+        executing = true;
+    }
+
+    CurrentMetrics::Increment metric_increment{CurrentMetrics::BackgroundSchedulePoolTask};
+
+    Stopwatch watch;
+    function();
+    UInt64 milliseconds = watch.elapsedMilliseconds();
+
+    /// If the task is executed longer than specified time, it will be logged.
+    static const int32_t slow_execution_threshold_ms = 50;
+
+    if (milliseconds >= slow_execution_threshold_ms)
+        LOG_INFO(&Logger::get("BackgroundSchedulePool"), "Executing " << name << " took " << milliseconds << " ms.");
+
+    {
+        std::lock_guard lock_schedule(schedule_mutex);
+
+        executing = false;
+
+        /// In case was scheduled while executing (including a scheduleAfter which expired) we schedule the task
+		/// on the queue. We don't call the function again here because this way all tasks
+		/// will have their chance to execute
+
+        if(scheduled)
+                pool.queue.enqueueNotification(new TaskNotification(shared_from_this()));
+    }
+
+}
+
+zkutil::WatchCallback BackgroundSchedulePool::TaskInfo::getWatchCallback()
+{
+     return [t=shared_from_this()](const ZooKeeperImpl::ZooKeeper::WatchResponse &) {
+         t->schedule();
+     };
+}
+
+
+// BackgroundSchedulePool
+
+BackgroundSchedulePool::BackgroundSchedulePool(size_t size)
+    : size(size)
+{
+    LOG_INFO(&Logger::get("BackgroundSchedulePool"), "Create BackgroundSchedulePool with " << size << " threads");
+
+    threads.resize(size);
+    for (auto & thread : threads)
+        thread = std::thread([this] { threadFunction(); });
+
+    delayed_thread = std::thread([this] { delayExecutionThreadFunction(); });
+}
+
+
+BackgroundSchedulePool::~BackgroundSchedulePool()
+{
+    try
+    {
+        {
+            std::unique_lock lock(delayed_tasks_lock);
+            shutdown = true;
+            wakeup_cond.notify_all();
+        }
+
+        queue.wakeUpAll();
+        delayed_thread.join();
+
+        LOG_TRACE(&Logger::get("BackgroundSchedulePool"), "Waiting for threads to finish.");
+        for (std::thread & thread : threads)
+            thread.join();
+    }
+    catch (...)
+    {
+        tryLogCurrentException(__PRETTY_FUNCTION__);
+    }
+}
+
+
+BackgroundSchedulePool::TaskHandle BackgroundSchedulePool::addTask(const std::string & name, const Task & task)
+{
+    return std::make_shared<TaskInfo>(*this, name, task);
+}
+
+
+void BackgroundSchedulePool::removeTask(const TaskHandle & task)
+{
+    task->deactivate();
+}
+
+
+void BackgroundSchedulePool::scheduleDelayedTask(const TaskHandle & task, size_t ms, std::lock_guard<std::mutex> & /* schedule_mutex_lock */)
+{
+    Poco::Timestamp current_time;
+
+    {
+        std::lock_guard lock(delayed_tasks_lock);
+
+        if (task->delayed)
+            delayed_tasks.erase(task->iterator);
+
+        task->iterator = delayed_tasks.emplace(current_time + (ms * 1000), task);
+        task->delayed = true;
+    }
+
+    wakeup_cond.notify_all();
+}
+
+
+void BackgroundSchedulePool::cancelDelayedTask(const TaskHandle & task, std::lock_guard<std::mutex> & /* schedule_mutex_lock */)
+{
+    {
+        std::lock_guard lock(delayed_tasks_lock);
+        delayed_tasks.erase(task->iterator);
+        task->delayed = false;
+    }
+
+    wakeup_cond.notify_all();
+}
+
+
+void BackgroundSchedulePool::threadFunction()
+{
+    setThreadName("BackgrSchedPool");
+
+    MemoryTracker memory_tracker;
+    memory_tracker.setMetric(CurrentMetrics::MemoryTrackingInBackgroundSchedulePool);
+    current_memory_tracker = &memory_tracker;
+
+    while (!shutdown)
+    {
+        if (Poco::AutoPtr<Poco::Notification> notification = queue.waitDequeueNotification())
+        {
+            TaskNotification & task_notification = static_cast<TaskNotification &>(*notification);
+            task_notification.execute();
+        }
+    }
+
+    current_memory_tracker = nullptr;
+}
+
+
+void BackgroundSchedulePool::delayExecutionThreadFunction()
+{
+    setThreadName("BckSchPoolDelay");
+
+    while (!shutdown)
+    {
+        TaskHandle task;
+        bool found = false;
+
+        {
+            std::unique_lock lock(delayed_tasks_lock);
+
+            while(!shutdown)
+            {
+                Poco::Timestamp min_time;
+
+                if (!delayed_tasks.empty())
+                {
+                    auto t = delayed_tasks.begin();
+                    min_time = t->first;
+                    task = t->second;
+                }
+
+                if (!task)
+                {
+                    wakeup_cond.wait(lock);
+                    continue;
+                }
+
+                Poco::Timestamp current_time;
+
+                if (min_time > current_time)
+                {
+                    wakeup_cond.wait_for(lock, std::chrono::microseconds(min_time - current_time));
+                    continue;
+                }
+                else
+                {
+                    /// We have a task ready for execution
+                    found = true;
+                    break;
+                }
+            }
+        }
+
+        if(found)
+            task->schedule();
+    }
+}
+
+}

dbms/src/Common/BackgroundSchedulePool.h

@@ -0,0 +1,120 @@
+#pragma once
+
+#include <Poco/Notification.h>
+#include <Poco/NotificationQueue.h>
+#include <Poco/Timestamp.h>
+#include <thread>
+#include <atomic>
+#include <mutex>
+#include <condition_variable>
+#include <vector>
+#include <map>
+#include <functional>
+#include <boost/noncopyable.hpp>
+#include <Common/ZooKeeper/Types.h>
+
+namespace DB
+{
+
+class TaskNotification;
+
+
+/** Executes functions scheduled at a specific point in time.
+  * Basically all tasks are added in a queue and precessed by worker threads.
+  *
+  * The most important difference between this and BackgroundProcessingPool
+  *  is that we have the guarantee that the same function is not executed from many workers in the same time.
+  *
+  * The usage scenario: instead starting a separate thread for each task,
+  *  register a task in BackgroundSchedulePool and when you need to run the task,
+  *  call schedule or scheduleAfter(duration) method.
+  */
+class BackgroundSchedulePool
+{
+public:
+    class TaskInfo;
+    using TaskHandle = std::shared_ptr<TaskInfo>;
+    using Tasks = std::multimap<Poco::Timestamp, TaskHandle>;
+    using Task = std::function<void()>;
+
+    class TaskInfo : public std::enable_shared_from_this<TaskInfo>, private boost::noncopyable
+    {
+    public:
+        TaskInfo(BackgroundSchedulePool & pool, const std::string & name, const Task & function);
+
+        /// All these methods waits for current execution of task.
+
+        /// Schedule for execution as soon as possible (if not already scheduled).
+        /// If the task was already scheduled with delay, the delay will be ignored.
+        bool schedule();
+
+        /// Schedule for execution after specified delay.
+        bool scheduleAfter(size_t ms);
+
+        /// Further attempts to schedule become no-op.
+        void deactivate();
+        void activate();
+
+        /// get zkutil::WatchCallback needed for zookeeper callbacks.
+
+        zkutil::WatchCallback getWatchCallback();
+
+    private:
+        friend class TaskNotification;
+        friend class BackgroundSchedulePool;
+
+        void execute();
+
+        std::mutex schedule_mutex;
+        std::mutex exec_mutex;
+
+        std::string name;
+        bool deactivated = false;
+        bool scheduled = false;
+        bool delayed = false;
+        bool executing = false;
+        BackgroundSchedulePool & pool;
+        Task function;
+
+        /// If the task is scheduled with delay, points to element of delayed_tasks.
+        Tasks::iterator iterator;
+    };
+
+    BackgroundSchedulePool(size_t size);
+    ~BackgroundSchedulePool();
+
+    TaskHandle addTask(const std::string & name, const Task & task);
+    void removeTask(const TaskHandle & task);
+    size_t getNumberOfThreads() const { return size; }
+
+private:
+    using Threads = std::vector<std::thread>;
+
+    void threadFunction();
+    void delayExecutionThreadFunction();
+
+    /// Schedule task for execution after specified delay from now.
+    void scheduleDelayedTask(const TaskHandle & task, size_t ms, std::lock_guard<std::mutex> &);
+
+    /// Remove task, that was scheduled with delay, from schedule.
+    void cancelDelayedTask(const TaskHandle & task, std::lock_guard<std::mutex> &);
+
+    /// Number for worker threads.
+    const size_t size;
+    std::atomic<bool> shutdown {false};
+    Threads threads;
+    Poco::NotificationQueue queue;
+
+    /// Delayed notifications.
+
+    std::condition_variable wakeup_cond;
+    std::mutex delayed_tasks_lock;
+    /// Thread waiting for next delayed task.
+    std::thread delayed_thread;
+    /// Tasks ordered by scheduled time.
+    Tasks delayed_tasks;
+};
+
+using BackgroundSchedulePoolPtr = std::shared_ptr<BackgroundSchedulePool>;
+
+}

dbms/src/Common/CurrentMetrics.cpp

@@ -9,6 +9,7 @@
     M(ReplicatedSend) \
     M(ReplicatedChecks) \
     M(BackgroundPoolTask) \
+    M(BackgroundSchedulePoolTask) \
     M(DiskSpaceReservedForMerge) \
     M(DistributedSend) \
     M(QueryPreempted) \
@@ -25,6 +26,7 @@
     M(LeaderReplica) \
     M(MemoryTracking) \
     M(MemoryTrackingInBackgroundProcessingPool) \
+    M(MemoryTrackingInBackgroundSchedulePool) \
     M(MemoryTrackingForMerges) \
     M(LeaderElection) \
     M(EphemeralNode) \

dbms/src/Common/ZooKeeper/LeaderElection.h

@@ -6,6 +6,7 @@
 #include <memory>
 #include <common/logger_useful.h>
 #include <Common/CurrentMetrics.h>
+#include <Common/BackgroundSchedulePool.h>
 
 
 namespace ProfileEvents
@@ -36,9 +37,10 @@ public:
       * It means that different participants of leader election have different identifiers
       *  and existence of more than one ephemeral node with same identifier indicates an error.
       */
-    LeaderElection(const std::string & path_, ZooKeeper & zookeeper_, LeadershipHandler handler_, const std::string & identifier_ = "")
-        : path(path_), zookeeper(zookeeper_), handler(handler_), identifier(identifier_)
+    LeaderElection(DB::BackgroundSchedulePool & pool_, const std::string & path_, ZooKeeper & zookeeper_, LeadershipHandler handler_, const std::string & identifier_ = "")
+        : pool(pool_), path(path_), zookeeper(zookeeper_), handler(handler_), identifier(identifier_)
     {
+        task_handle = pool.addTask("LeaderElection", [this] { threadFunction(); });
         createNode();
     }
 
@@ -48,17 +50,18 @@ public:
             return;
 
         shutdown_called = true;
-        event->set();
-        if (thread.joinable())
-            thread.join();
+        task_handle->deactivate();
     }
 
     ~LeaderElection()
     {
         releaseNode();
+        pool.removeTask(task_handle);
     }
 
 private:
+    DB::BackgroundSchedulePool & pool;
+    DB::BackgroundSchedulePool::TaskHandle task_handle;
     std::string path;
     ZooKeeper & zookeeper;
     LeadershipHandler handler;
@@ -67,9 +70,7 @@ private:
     EphemeralNodeHolderPtr node;
     std::string node_name;
 
-    std::thread thread;
     std::atomic<bool> shutdown_called {false};
-    EventPtr event = std::make_shared<Poco::Event>();
 
     CurrentMetrics::Increment metric_increment{CurrentMetrics::LeaderElection};
 
@@ -81,7 +82,8 @@ private:
         std::string node_path = node->getPath();
         node_name = node_path.substr(node_path.find_last_of('/') + 1);
 
-        thread = std::thread(&LeaderElection::threadFunction, this);
+        task_handle->activate();
+        task_handle->schedule();
     }
 
     void releaseNode()
@@ -92,45 +94,42 @@ private:
 
     void threadFunction()
     {
-        while (!shutdown_called)
+        bool success = false;
+
+        try
         {
-            bool success = false;
+            Strings children = zookeeper.getChildren(path);
+            std::sort(children.begin(), children.end());
+            auto it = std::lower_bound(children.begin(), children.end(), node_name);
+            if (it == children.end() || *it != node_name)
+                throw Poco::Exception("Assertion failed in LeaderElection");
 
-            try
+            if (it == children.begin())
             {
-                Strings children = zookeeper.getChildren(path);
-                std::sort(children.begin(), children.end());
-                auto it = std::lower_bound(children.begin(), children.end(), node_name);
-                if (it == children.end() || *it != node_name)
-                    throw Poco::Exception("Assertion failed in LeaderElection");
-
-                if (it == children.begin())
-                {
-                    ProfileEvents::increment(ProfileEvents::LeaderElectionAcquiredLeadership);
-                    handler();
-                    return;
-                }
-
-                if (zookeeper.exists(path + "/" + *(it - 1), nullptr, event))
-                    event->wait();
-
-                success = true;
-            }
-            catch (const KeeperException & e)
-            {
-                DB::tryLogCurrentException("LeaderElection");
-
-                if (e.code == ZooKeeperImpl::ZooKeeper::ZSESSIONEXPIRED)
-                    break;
-            }
-            catch (...)
-            {
-                DB::tryLogCurrentException("LeaderElection");
+                ProfileEvents::increment(ProfileEvents::LeaderElectionAcquiredLeadership);
+                handler();
+                return;
             }
 
-            if (!success)
-                event->tryWait(10 * 1000);
+            if (!zookeeper.existsWatch(path + "/" + *(it - 1), nullptr, task_handle->getWatchCallback()))
+                task_handle->schedule();
+
+            success = true;
         }
+        catch (const KeeperException & e)
+        {
+            DB::tryLogCurrentException("LeaderElection");
+
+            if (e.code == ZooKeeperImpl::ZooKeeper::ZSESSIONEXPIRED)
+                return;
+        }
+        catch (...)
+        {
+            DB::tryLogCurrentException("LeaderElection");
+        }
+
+        if (!success)
+            task_handle->scheduleAfter(10 * 1000);
     }
 };
 

dbms/src/Common/ZooKeeper/ZooKeeper.cpp

@@ -367,6 +367,16 @@ std::string ZooKeeper::get(const std::string & path, Stat * stat, const EventPtr
         throw KeeperException("Can't get data for node " + path + ": node doesn't exist", code);
 }
 
+std::string ZooKeeper::getWatch(const std::string & path, Stat * stat, WatchCallback watch_callback)
+{
+    int32_t code = 0;
+    std::string res;
+    if (tryGetWatch(path, res, stat, watch_callback, &code))
+        return res;
+    else
+        throw KeeperException("Can't get data for node " + path + ": node doesn't exist", code);
+}
+
 bool ZooKeeper::tryGet(const std::string & path, std::string & res, Stat * stat, const EventPtr & watch, int * return_code)
 {
     return tryGetWatch(path, res, stat, callbackForEvent(watch), return_code);

dbms/src/Common/ZooKeeper/ZooKeeper.h

@@ -113,6 +113,7 @@ public:
     bool existsWatch(const std::string & path, Stat * stat, WatchCallback watch_callback);
 
     std::string get(const std::string & path, Stat * stat = nullptr, const EventPtr & watch = nullptr);
+    std::string getWatch(const std::string & path, Stat * stat, WatchCallback watch_callback);
 
     /// Doesn't not throw in the following cases:
     /// * The node doesn't exist. Returns false in this case.

dbms/src/Common/hex.h

@@ -39,6 +39,52 @@ inline void writeHexByteLowercase(UInt8 byte, void * out)
 }
 
 
+/// Produces hex representation of an unsigned int with leading zeros (for checksums)
+template <typename TUInt>
+inline void writeHexUIntImpl(TUInt uint, char * out, const char * const table)
+{
+    union
+    {
+        TUInt value;
+        UInt8 uint8[sizeof(TUInt)];
+    };
+
+    value = uint;
+
+    /// Use little endian
+    for (size_t i = 0; i < sizeof(TUInt); ++i)
+        memcpy(out + i * 2, &table[static_cast<size_t>(uint8[sizeof(TUInt) - 1 - i]) * 2], 2);
+}
+
+template <typename TUInt>
+inline void writeHexUIntUppercase(TUInt uint, char * out)
+{
+    writeHexUIntImpl(uint, out, hex_byte_to_char_uppercase_table);
+}
+
+template <typename TUInt>
+inline void writeHexUIntLowercase(TUInt uint, char * out)
+{
+    writeHexUIntImpl(uint, out, hex_byte_to_char_lowercase_table);
+}
+
+template <typename TUInt>
+std::string getHexUIntUppercase(TUInt uint)
+{
+    std::string res(sizeof(TUInt) * 2, '\0');
+    writeHexUIntUppercase(uint, res.data());
+    return res;
+}
+
+template <typename TUInt>
+std::string getHexUIntLowercase(TUInt uint)
+{
+    std::string res(sizeof(TUInt) * 2, '\0');
+    writeHexUIntLowercase(uint, res.data());
+    return res;
+}
+
+
 /// Maps 0..9, A..F, a..f to 0..15. Other chars are mapped to implementation specific value.
 
 extern const char * const hex_char_to_digit_table;

dbms/src/Common/localBackup.cpp

@@ -1,3 +1,4 @@
+#include "localBackup.h"
 #include <sys/stat.h>
 #include <string>
 #include <iostream>
@@ -18,8 +19,12 @@ namespace ErrorCodes
 }
 
 
-static void localBackupImpl(const Poco::Path & source_path, const Poco::Path & destination_path, size_t level)
+static void localBackupImpl(const Poco::Path & source_path, const Poco::Path & destination_path, size_t level,
+                            std::optional<size_t> max_level)
 {
+    if (max_level && level > max_level.value())
+        return;
+
     if (level >= 1000)
         throw DB::Exception("Too deep recursion", DB::ErrorCodes::TOO_DEEP_RECURSION);
 
@@ -66,12 +71,12 @@ static void localBackupImpl(const Poco::Path & source_path, const Poco::Path & d
         }
         else
         {
-            localBackupImpl(source, destination, level + 1);
+            localBackupImpl(source, destination, level + 1, max_level);
         }
     }
 }
 
-void localBackup(const Poco::Path & source_path, const Poco::Path & destination_path)
+void localBackup(const Poco::Path & source_path, const Poco::Path & destination_path, std::optional<size_t> max_level)
 {
     if (Poco::File(destination_path).exists()
         && Poco::DirectoryIterator(destination_path) != Poco::DirectoryIterator())
@@ -90,7 +95,7 @@ void localBackup(const Poco::Path & source_path, const Poco::Path & destination_
     {
         try
         {
-            localBackupImpl(source_path, destination_path, 0);
+            localBackupImpl(source_path, destination_path, 0, max_level);
         }
         catch (const DB::ErrnoException & e)
         {

dbms/src/Common/localBackup.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <Poco/Path.h>
+#include <optional>
 
 
 /** Creates a local (at the same mount point) backup (snapshot) directory.
@@ -12,5 +13,9 @@
   * This protects data from accidental deletion or modification,
   *  and is intended to be used as a simple means of protection against a human or program error,
   *  but not from a hardware failure.
+  *
+  *  If max_level is specified, than only files which depth relative source_path less or equal max_level will be copied.
+  *  So, if max_level=0 than only direct file child are copied.
   */
-void localBackup(const Poco::Path & source_path, const Poco::Path & destination_path);
+void localBackup(const Poco::Path & source_path, const Poco::Path & destination_path, std::optional<size_t> max_level = {});
+

dbms/src/DataStreams/BlockInputStreamFromRowInputStream.cpp

@@ -14,6 +14,7 @@ namespace ErrorCodes
     extern const int CANNOT_READ_ARRAY_FROM_TEXT;
     extern const int CANNOT_PARSE_NUMBER;
     extern const int CANNOT_PARSE_UUID;
+    extern const int TOO_LARGE_STRING_SIZE;
 }
 
 
@@ -37,7 +38,8 @@ static bool isParseError(int code)
         || code == ErrorCodes::CANNOT_PARSE_DATETIME
         || code == ErrorCodes::CANNOT_READ_ARRAY_FROM_TEXT
         || code == ErrorCodes::CANNOT_PARSE_NUMBER
-        || code == ErrorCodes::CANNOT_PARSE_UUID;
+        || code == ErrorCodes::CANNOT_PARSE_UUID
+        || code == ErrorCodes::TOO_LARGE_STRING_SIZE;
 }
 
 

dbms/src/DataStreams/JSONEachRowRowInputStream.cpp

@@ -130,7 +130,15 @@ bool JSONEachRowRowInputStream::read(MutableColumns & columns)
 
         read_columns[index] = true;
 
-        header.getByPosition(index).type->deserializeTextJSON(*columns[index], istr);
+        try
+        {
+            header.getByPosition(index).type->deserializeTextJSON(*columns[index], istr);
+        }
+        catch (Exception & e)
+        {
+            e.addMessage("(while read the value of key " + name_ref.toString() + ")");
+            throw;
+        }
     }
 
     /// Fill non-visited columns with the default values.

dbms/src/DataStreams/PushingToViewsBlockOutputStream.cpp

@@ -18,6 +18,10 @@ PushingToViewsBlockOutputStream::PushingToViewsBlockOutputStream(
       */
     addTableLock(storage->lockStructure(true, __PRETTY_FUNCTION__));
 
+    /// If the "root" table deduplactes blocks, there are no need to make deduplication for children
+    /// Moreover, deduplication for AggregatingMergeTree children could produce false positives due to low size of inserting blocks
+    bool disable_deduplication_for_children = !no_destination && storage->supportsDeduplication();
+
     if (!table.empty())
     {
         Dependencies dependencies = context.getDependencies(database, table);
@@ -27,7 +31,8 @@ PushingToViewsBlockOutputStream::PushingToViewsBlockOutputStream(
         {
             views_context = std::make_unique<Context>(context);
             // Do not deduplicate insertions into MV if the main insertion is Ok
-            views_context->getSettingsRef().insert_deduplicate = false;
+            if (disable_deduplication_for_children)
+                views_context->getSettingsRef().insert_deduplicate = false;
         }
 
         for (const auto & database_table : dependencies)
@@ -89,4 +94,51 @@ void PushingToViewsBlockOutputStream::write(const Block & block)
     }
 }
 
+void PushingToViewsBlockOutputStream::writePrefix()
+{
+    if (output)
+        output->writePrefix();
+
+    for (auto & view : views)
+    {
+        try
+        {
+            view.out->writePrefix();
+        }
+        catch (Exception & ex)
+        {
+            ex.addMessage("while write prefix to view " + view.database + "." + view.table);
+            throw;
+        }
+    }
+}
+
+void PushingToViewsBlockOutputStream::writeSuffix()
+{
+    if (output)
+        output->writeSuffix();
+
+    for (auto & view : views)
+    {
+        try
+        {
+            view.out->writeSuffix();
+        }
+        catch (Exception & ex)
+        {
+            ex.addMessage("while write prefix to view " + view.database + "." + view.table);
+            throw;
+        }
+    }
+}
+
+void PushingToViewsBlockOutputStream::flush()
+{
+    if (output)
+        output->flush();
+
+    for (auto & view : views)
+        view.out->flush();
+}
+
 }

dbms/src/DataStreams/PushingToViewsBlockOutputStream.h

@@ -25,32 +25,9 @@ public:
     Block getHeader() const override { return storage->getSampleBlock(); }
     void write(const Block & block) override;
 
-    void flush() override
-    {
-        if (output)
-            output->flush();
-
-        for (auto & view : views)
-            view.out->flush();
-    }
-
-    void writePrefix() override
-    {
-        if (output)
-            output->writePrefix();
-
-        for (auto & view : views)
-            view.out->writePrefix();
-    }
-
-    void writeSuffix() override
-    {
-        if (output)
-            output->writeSuffix();
-
-        for (auto & view : views)
-            view.out->writeSuffix();
-    }
+    void flush() override;
+    void writePrefix() override;
+    void writeSuffix() override;
 
 private:
     StoragePtr storage;

dbms/src/DataTypes/DataTypeDate.cpp

@@ -11,12 +11,12 @@ namespace DB
 
 void DataTypeDate::serializeText(const IColumn & column, size_t row_num, WriteBuffer & ostr) const
 {
-    writeDateText(DayNum_t(static_cast<const ColumnUInt16 &>(column).getData()[row_num]), ostr);
+    writeDateText(DayNum(static_cast<const ColumnUInt16 &>(column).getData()[row_num]), ostr);
 }
 
 static void deserializeText(IColumn & column, ReadBuffer & istr)
 {
-    DayNum_t x;
+    DayNum x;
     readDateText(x, istr);
     static_cast<ColumnUInt16 &>(column).getData().push_back(x);
 }
@@ -40,7 +40,7 @@ void DataTypeDate::serializeTextQuoted(const IColumn & column, size_t row_num, W
 
 void DataTypeDate::deserializeTextQuoted(IColumn & column, ReadBuffer & istr) const
 {
-    DayNum_t x;
+    DayNum x;
     assertChar('\'', istr);
     readDateText(x, istr);
     assertChar('\'', istr);
@@ -56,7 +56,7 @@ void DataTypeDate::serializeTextJSON(const IColumn & column, size_t row_num, Wri
 
 void DataTypeDate::deserializeTextJSON(IColumn & column, ReadBuffer & istr) const
 {
-    DayNum_t x;
+    DayNum x;
     assertChar('"', istr);
     readDateText(x, istr);
     assertChar('"', istr);

dbms/src/Dictionaries/HTTPDictionarySource.cpp

@@ -29,16 +29,6 @@ HTTPDictionarySource::HTTPDictionarySource(const DictionaryStructure & dict_stru
     context(context),
     timeouts(ConnectionTimeouts::getHTTPTimeouts(context.getSettingsRef()))
 {
-    if (update_field.empty())
-        return;
-
-    /// TODO This code is totally wrong and ignorant.
-    /// What if URL contains fragment (#). What if update_field contains characters that must be %-encoded.
-    std::string::size_type option = url.find("?");
-    if (option == std::string::npos)
-        update_field = '?' + update_field;
-    else
-        update_field = '&' + update_field;
 }
 
 HTTPDictionarySource::HTTPDictionarySource(const HTTPDictionarySource & other)
@@ -54,7 +44,7 @@ HTTPDictionarySource::HTTPDictionarySource(const HTTPDictionarySource & other)
 {
 }
 
-std::string HTTPDictionarySource::getUpdateFieldAndDate()
+void HTTPDictionarySource::getUpdateFieldAndDate(Poco::URI & uri)
 {
     if (update_time != std::chrono::system_clock::from_time_t(0))
     {
@@ -64,14 +54,14 @@ std::string HTTPDictionarySource::getUpdateFieldAndDate()
         char buffer [80];
         struct tm * timeinfo;
         timeinfo = localtime (&hr_time);
-        strftime(buffer, 80, "=%Y-%m-%d%%20%H:%M:%S", timeinfo);
+        strftime(buffer, 80, "%Y-%m-%d %H:%M:%S", timeinfo);
         std::string str_time(buffer);
-        return url + update_field + str_time;
+        uri.addQueryParameter(update_field, str_time);
     }
     else
     {
         update_time = std::chrono::system_clock::now();
-        return url + update_field + "=0000-00-00%2000:00:00"; ///for initial load
+        uri.addQueryParameter(update_field, "0000-00-00 00:00:00");
     }
 }
 
@@ -87,9 +77,9 @@ BlockInputStreamPtr HTTPDictionarySource::loadAll()
 
 BlockInputStreamPtr HTTPDictionarySource::loadUpdatedAll()
 {
-    std::string url_update = getUpdateFieldAndDate();
-    LOG_TRACE(log, "loadUpdatedAll " + url_update);
-    Poco::URI uri(url_update);
+    Poco::URI uri(url);
+    getUpdateFieldAndDate(uri);
+    LOG_TRACE(log, "loadUpdatedAll " + uri.toString());
     auto in_ptr = std::make_unique<ReadWriteBufferFromHTTP>(uri, Poco::Net::HTTPRequest::HTTP_GET,
                                                             ReadWriteBufferFromHTTP::OutStreamCallback(), timeouts);
     auto input_stream = context.getInputFormat(format, *in_ptr, sample_block, max_block_size);

dbms/src/Dictionaries/HTTPDictionarySource.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <Poco/URI.h>
 #include <Dictionaries/IDictionarySource.h>
 #include <Dictionaries/DictionaryStructure.h>
 #include <common/LocalDateTime.h>
@@ -43,7 +44,7 @@ public:
     std::string toString() const override;
 
 private:
-    std::string getUpdateFieldAndDate();
+    void getUpdateFieldAndDate(Poco::URI & uri);
 
     Poco::Logger * log;
 

dbms/src/Functions/FunctionsComparison.h

@@ -828,7 +828,7 @@ private:
 
         if (is_date)
         {
-            DayNum_t date;
+            DayNum date;
             ReadBufferFromMemory in(string_value.data, string_value.size);
             readDateText(date, in);
             if (!in.eof())

dbms/src/Functions/FunctionsConversion.h

@@ -112,7 +112,7 @@ struct ToDateTimeImpl
 
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d));
+        return time_zone.fromDayNum(DayNum(d));
     }
 };
 
@@ -175,7 +175,7 @@ struct FormatImpl<DataTypeDate>
 {
     static void execute(const DataTypeDate::FieldType x, WriteBuffer & wb, const DataTypeDate *, const DateLUTImpl *)
     {
-        writeDateText(DayNum_t(x), wb);
+        writeDateText(DayNum(x), wb);
     }
 };
 
@@ -307,7 +307,7 @@ template <typename DataType> void parseImpl(typename DataType::FieldType & x, Re
 
 template <> inline void parseImpl<DataTypeDate>(DataTypeDate::FieldType & x, ReadBuffer & rb, const DateLUTImpl *)
 {
-    DayNum_t tmp(0);
+    DayNum tmp(0);
     readDateText(tmp, rb);
     x = tmp;
 }

dbms/src/Functions/FunctionsDateTime.h

@@ -133,7 +133,7 @@ struct ToMondayImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toFirstDayNumOfWeek(DayNum_t(d));
+        return time_zone.toFirstDayNumOfWeek(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -149,7 +149,7 @@ struct ToStartOfMonthImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toFirstDayNumOfMonth(DayNum_t(d));
+        return time_zone.toFirstDayNumOfMonth(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -165,7 +165,7 @@ struct ToStartOfQuarterImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toFirstDayNumOfQuarter(DayNum_t(d));
+        return time_zone.toFirstDayNumOfQuarter(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -181,7 +181,7 @@ struct ToStartOfYearImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toFirstDayNumOfYear(DayNum_t(d));
+        return time_zone.toFirstDayNumOfYear(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -281,7 +281,7 @@ struct ToYearImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toYear(DayNum_t(d));
+        return time_zone.toYear(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -297,7 +297,7 @@ struct ToQuarterImpl
     }
     static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toQuarter(DayNum_t(d));
+        return time_zone.toQuarter(DayNum(d));
     }
 
     using FactorTransform = ToStartOfYearImpl;
@@ -313,7 +313,7 @@ struct ToMonthImpl
     }
     static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toMonth(DayNum_t(d));
+        return time_zone.toMonth(DayNum(d));
     }
 
     using FactorTransform = ToStartOfYearImpl;
@@ -329,7 +329,7 @@ struct ToDayOfMonthImpl
     }
     static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toDayOfMonth(DayNum_t(d));
+        return time_zone.toDayOfMonth(DayNum(d));
     }
 
     using FactorTransform = ToStartOfMonthImpl;
@@ -345,7 +345,7 @@ struct ToDayOfWeekImpl
     }
     static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toDayOfWeek(DayNum_t(d));
+        return time_zone.toDayOfWeek(DayNum(d));
     }
 
     using FactorTransform = ToMondayImpl;
@@ -410,7 +410,7 @@ struct ToRelativeYearNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toYear(DayNum_t(d));
+        return time_zone.toYear(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -426,7 +426,7 @@ struct ToRelativeQuarterNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeQuarterNum(DayNum_t(d));
+        return time_zone.toRelativeQuarterNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -442,7 +442,7 @@ struct ToRelativeMonthNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeMonthNum(DayNum_t(d));
+        return time_zone.toRelativeMonthNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -458,7 +458,7 @@ struct ToRelativeWeekNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeWeekNum(DayNum_t(d));
+        return time_zone.toRelativeWeekNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -474,7 +474,7 @@ struct ToRelativeDayNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl &)
     {
-        return static_cast<DayNum_t>(d);
+        return static_cast<DayNum>(d);
     }
 
     using FactorTransform = ZeroTransform;
@@ -491,7 +491,7 @@ struct ToRelativeHourNumImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeHourNum(DayNum_t(d));
+        return time_zone.toRelativeHourNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -507,7 +507,7 @@ struct ToRelativeMinuteNumImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeMinuteNum(DayNum_t(d));
+        return time_zone.toRelativeMinuteNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -523,7 +523,7 @@ struct ToRelativeSecondNumImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d));
+        return time_zone.fromDayNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -539,7 +539,7 @@ struct ToYYYYMMImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toNumYYYYMM(static_cast<DayNum_t>(d));
+        return time_zone.toNumYYYYMM(static_cast<DayNum>(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -555,7 +555,7 @@ struct ToYYYYMMDDImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toNumYYYYMMDD(static_cast<DayNum_t>(d));
+        return time_zone.toNumYYYYMMDD(static_cast<DayNum>(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -571,7 +571,7 @@ struct ToYYYYMMDDhhmmssImpl
     }
     static inline UInt64 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toNumYYYYMMDDhhmmss(time_zone.toDate(static_cast<DayNum_t>(d)));
+        return time_zone.toNumYYYYMMDDhhmmss(time_zone.toDate(static_cast<DayNum>(d)));
     }
 
     using FactorTransform = ZeroTransform;
@@ -732,7 +732,7 @@ struct AddSecondsImpl
 
     static inline UInt32 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d)) + delta;
+        return time_zone.fromDayNum(DayNum(d)) + delta;
     }
 };
 
@@ -747,7 +747,7 @@ struct AddMinutesImpl
 
     static inline UInt32 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d)) + delta * 60;
+        return time_zone.fromDayNum(DayNum(d)) + delta * 60;
     }
 };
 
@@ -762,7 +762,7 @@ struct AddHoursImpl
 
     static inline UInt32 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d)) + delta * 3600;
+        return time_zone.fromDayNum(DayNum(d)) + delta * 3600;
     }
 };
 
@@ -807,7 +807,7 @@ struct AddMonthsImpl
 
     static inline UInt16 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.addMonths(DayNum_t(d), delta);
+        return time_zone.addMonths(DayNum(d), delta);
     }
 };
 
@@ -822,7 +822,7 @@ struct AddYearsImpl
 
     static inline UInt16 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.addYears(DayNum_t(d), delta);
+        return time_zone.addYears(DayNum(d), delta);
     }
 };
 

dbms/src/IO/ReadHelpers.h

@@ -483,7 +483,7 @@ inline void readDateText(LocalDate & date, ReadBuffer & buf)
         readDateTextFallback(date, buf);
 }
 
-inline void readDateText(DayNum_t & date, ReadBuffer & buf)
+inline void readDateText(DayNum & date, ReadBuffer & buf)
 {
     LocalDate local_date;
     readDateText(local_date, buf);

dbms/src/IO/WriteHelpers.h

@@ -537,7 +537,7 @@ inline void writeDateText(const LocalDate & date, WriteBuffer & buf)
 }
 
 template <char delimiter = '-'>
-inline void writeDateText(DayNum_t date, WriteBuffer & buf)
+inline void writeDateText(DayNum date, WriteBuffer & buf)
 {
     if (unlikely(!date))
     {

dbms/src/Interpreters/ActionLocksManager.cpp

@@ -0,0 +1,97 @@
+#include "ActionLocksManager.h"
+#include <Interpreters/Context.h>
+#include <Databases/IDatabase.h>
+#include <Storages/IStorage.h>
+
+
+namespace DB
+{
+
+namespace ActionLocks
+{
+    extern const StorageActionBlockType PartsMerge = 1;
+    extern const StorageActionBlockType PartsFetch = 2;
+    extern const StorageActionBlockType PartsSend = 3;
+    extern const StorageActionBlockType ReplicationQueue = 4;
+}
+
+
+template <typename F>
+inline void forEachTable(Context & context, F && f)
+{
+    for (auto & elem : context.getDatabases())
+        for (auto iterator = elem.second->getIterator(context); iterator->isValid(); iterator->next())
+            f(iterator->table());
+
+}
+
+void ActionLocksManager::add(StorageActionBlockType action_type)
+{
+    forEachTable(global_context, [&] (const StoragePtr & table)
+    {
+        ActionLock action_lock = table->getActionLock(action_type);
+
+        if (!action_lock.expired())
+        {
+            std::lock_guard<std::mutex> lock(mutex);
+            storage_locks[table.get()][action_type] = std::move(action_lock);
+        }
+    });
+}
+
+void ActionLocksManager::add(const String & database_name, const String & table_name, StorageActionBlockType action_type)
+{
+    if (auto table = global_context.tryGetTable(database_name, table_name))
+    {
+        ActionLock action_lock = table->getActionLock(action_type);
+
+        if (!action_lock.expired())
+        {
+            std::lock_guard<std::mutex> lock(mutex);
+            storage_locks[table.get()][action_type] = std::move(action_lock);
+        }
+    }
+}
+
+void ActionLocksManager::remove(StorageActionBlockType action_type)
+{
+    std::lock_guard<std::mutex> lock(mutex);
+
+    for (auto & storage_elem : storage_locks)
+        storage_elem.second.erase(action_type);
+}
+
+void ActionLocksManager::remove(const String & database_name, const String & table_name, StorageActionBlockType action_type)
+{
+    if (auto table = global_context.tryGetTable(database_name, table_name))
+    {
+        std::lock_guard<std::mutex> lock(mutex);
+
+        if (storage_locks.count(table.get()))
+            storage_locks[table.get()].erase(action_type);
+    }
+}
+
+void ActionLocksManager::cleanExpired()
+{
+    std::lock_guard<std::mutex> lock(mutex);
+
+    for (auto it_storage = storage_locks.begin(); it_storage != storage_locks.end(); )
+    {
+        auto & locks = it_storage->second;
+        for (auto it_lock = locks.begin(); it_lock != locks.end(); )
+        {
+            if (it_lock->second.expired())
+                it_lock = locks.erase(it_lock);
+            else
+                ++it_lock;
+        }
+
+        if (locks.empty())
+            it_storage = storage_locks.erase(it_storage);
+        else
+            ++it_storage;
+    }
+}
+
+}

dbms/src/Interpreters/ActionLocksManager.h

@@ -0,0 +1,45 @@
+#pragma once
+#include <Core/Types.h>
+#include <Common/ActionLock.h>
+#include <unordered_map>
+#include <mutex>
+
+
+namespace DB
+{
+
+class IStorage;
+class Context;
+
+/// Holds ActionLocks for tables
+/// Does not store pointers to tables
+class ActionLocksManager
+{
+public:
+    explicit ActionLocksManager(Context & global_context_) : global_context(global_context_) {}
+
+    /// Adds new locks for each table
+    void add(StorageActionBlockType action_type);
+    /// Add new lock for a table if it has not been already added
+    void add(const String & database_name, const String & table_name, StorageActionBlockType action_type);
+
+    /// Remove locks for all tables
+    void remove(StorageActionBlockType action_type);
+    /// Removes a lock for a table if it exists
+    void remove(const String & database_name, const String & table_name, StorageActionBlockType action_type);
+
+    /// Removes all locks of non-existing tables
+    void cleanExpired();
+
+private:
+    Context & global_context;
+
+    using StorageRawPtr = const IStorage *;
+    using Locks = std::unordered_map<size_t, ActionLock>;
+    using StorageLocks = std::unordered_map<StorageRawPtr, Locks>;
+
+    mutable std::mutex mutex;
+    StorageLocks storage_locks;
+};
+
+}

dbms/src/Interpreters/Compiler.cpp

@@ -239,6 +239,7 @@ void Compiler::compile(
             " -isystem " INTERNAL_COMPILER_HEADERS_ROOT "/usr/include/c++/*/backward"
             " -isystem " INTERNAL_COMPILER_HEADERS_ROOT "/usr/include/clang/*/include"                  /// if compiler is clang (from package)
             " -isystem " INTERNAL_COMPILER_HEADERS_ROOT "/usr/local/lib/clang/*/include"                /// if clang installed manually
+            " -isystem " INTERNAL_COMPILER_HEADERS_ROOT "/usr/lib/clang/*/include"                      /// if clang build from submodules
             " -isystem " INTERNAL_COMPILER_HEADERS_ROOT "/usr/lib/gcc/" CMAKE_LIBRARY_ARCHITECTURE "/*/include-fixed"
             " -isystem " INTERNAL_COMPILER_HEADERS_ROOT "/usr/lib/gcc/" CMAKE_LIBRARY_ARCHITECTURE "/*/include"
             " -isystem " INTERNAL_COMPILER_HEADERS_ROOT "/usr/local/include"                            /// if something installed manually

dbms/src/Interpreters/Context.cpp

@@ -15,6 +15,7 @@
 #include <Common/setThreadName.h>
 #include <Common/Stopwatch.h>
 #include <Common/formatReadable.h>
+#include <Common/BackgroundSchedulePool.h>
 #include <DataStreams/FormatFactory.h>
 #include <Databases/IDatabase.h>
 #include <Storages/IStorage.h>
@@ -24,6 +25,7 @@
 #include <Storages/MergeTree/MergeTreeSettings.h>
 #include <Storages/CompressionSettingsSelector.h>
 #include <TableFunctions/TableFunctionFactory.h>
+#include <Interpreters/ActionLocksManager.h>
 #include <Interpreters/Settings.h>
 #include <Interpreters/RuntimeComponentsFactory.h>
 #include <Interpreters/ISecurityManager.h>
@@ -131,6 +133,7 @@ struct ContextShared
     ConfigurationPtr users_config;                          /// Config with the users, profiles and quotas sections.
     InterserverIOHandler interserver_io_handler;            /// Handler for interserver communication.
     BackgroundProcessingPoolPtr background_pool;            /// The thread pool for the background work performed by the tables.
+    BackgroundSchedulePoolPtr schedule_pool;                /// A thread pool that can run different jobs in background (used in replicated tables)
     MultiVersion<Macros> macros;                            /// Substitutions extracted from config.
     std::unique_ptr<Compiler> compiler;                     /// Used for dynamic compilation of queries' parts if it necessary.
     std::shared_ptr<DDLWorker> ddl_worker;                  /// Process ddl commands from zk.
@@ -139,7 +142,7 @@ struct ContextShared
     std::unique_ptr<MergeTreeSettings> merge_tree_settings; /// Settings of MergeTree* engines.
     size_t max_table_size_to_drop = 50000000000lu;          /// Protects MergeTree tables from accidental DROP (50GB by default)
     String format_schema_path;                              /// Path to a directory that contains schema files used by input formats.
-
+    ActionLocksManagerPtr action_locks_manager;             /// Set of storages' action lockers
 
     /// Named sessions. The user could specify session identifier to reuse settings and temporary tables in subsequent requests.
 
@@ -1328,6 +1331,14 @@ BackgroundProcessingPool & Context::getBackgroundPool()
     return *shared->background_pool;
 }
 
+BackgroundSchedulePool & Context::getSchedulePool()
+{
+    auto lock = getLock();
+    if (!shared->schedule_pool)
+        shared->schedule_pool = std::make_shared<BackgroundSchedulePool>(settings.background_schedule_pool_size);
+    return *shared->schedule_pool;
+}
+
 void Context::setDDLWorker(std::shared_ptr<DDLWorker> ddl_worker)
 {
     auto lock = getLock();
@@ -1721,6 +1732,16 @@ void Context::setFormatSchemaPath(const String & path)
     shared->format_schema_path = path;
 }
 
+std::shared_ptr<ActionLocksManager> Context::getActionLocksManager()
+{
+    auto lock = getLock();
+
+    if (!shared->action_locks_manager)
+        shared->action_locks_manager = std::make_shared<ActionLocksManager>(getGlobalContext());
+
+    return shared->action_locks_manager;
+}
+
 
 SessionCleaner::~SessionCleaner()
 {

dbms/src/Interpreters/Context.h

@@ -40,6 +40,7 @@ class ExternalDictionaries;
 class ExternalModels;
 class InterserverIOHandler;
 class BackgroundProcessingPool;
+class BackgroundSchedulePool;
 class MergeList;
 class Cluster;
 class Compiler;
@@ -69,6 +70,8 @@ using BlockOutputStreamPtr = std::shared_ptr<IBlockOutputStream>;
 class Block;
 struct SystemLogs;
 using SystemLogsPtr = std::shared_ptr<SystemLogs>;
+class ActionLocksManager;
+using ActionLocksManagerPtr = std::shared_ptr<ActionLocksManager>;
 
 
 /// (database name, table name)
@@ -328,6 +331,7 @@ public:
     void dropCaches() const;
 
     BackgroundProcessingPool & getBackgroundPool();
+    BackgroundSchedulePool & getSchedulePool();
 
     void setDDLWorker(std::shared_ptr<DDLWorker> ddl_worker);
     DDLWorker & getDDLWorker() const;
@@ -370,6 +374,8 @@ public:
 
     void shutdown();
 
+    ActionLocksManagerPtr getActionLocksManager();
+
     enum class ApplicationType
     {
         SERVER,         /// The program is run as clickhouse-server daemon (default behavior)

dbms/src/Interpreters/ExpressionAnalyzer.cpp

@@ -1486,7 +1486,7 @@ void ExpressionAnalyzer::tryMakeSetFromSubquery(const ASTPtr & subquery_or_table
             return;
     }
 
-    prepared_sets[subquery_or_table_name.get()] = std::move(set);
+    prepared_sets[subquery_or_table_name->range] = std::move(set);
 }
 
 
@@ -1515,7 +1515,7 @@ void ExpressionAnalyzer::makeSetsForIndexImpl(const ASTPtr & node, const Block &
         {
             const ASTPtr & arg = args.children.at(1);
 
-            if (!prepared_sets.count(arg.get())) /// Not already prepared.
+            if (!prepared_sets.count(arg->range)) /// Not already prepared.
             {
                 if (typeid_cast<ASTSubquery *>(arg.get()) || typeid_cast<ASTIdentifier *>(arg.get()))
                 {
@@ -1550,7 +1550,7 @@ void ExpressionAnalyzer::makeSet(const ASTFunction * node, const Block & sample_
     const ASTPtr & arg = args.children.at(1);
 
     /// Already converted.
-    if (prepared_sets.count(arg.get()))
+    if (prepared_sets.count(arg->range))
         return;
 
     /// If the subquery or table name for SELECT.
@@ -1573,7 +1573,7 @@ void ExpressionAnalyzer::makeSet(const ASTFunction * node, const Block & sample_
 
                 if (storage_set)
                 {
-                    prepared_sets[arg.get()] = storage_set->getSet();
+                    prepared_sets[arg->range] = storage_set->getSet();
                     return;
                 }
             }
@@ -1584,7 +1584,7 @@ void ExpressionAnalyzer::makeSet(const ASTFunction * node, const Block & sample_
         /// If you already created a Set with the same subquery / table.
         if (subquery_for_set.set)
         {
-            prepared_sets[arg.get()] = subquery_for_set.set;
+            prepared_sets[arg->range] = subquery_for_set.set;
             return;
         }
 
@@ -1630,7 +1630,7 @@ void ExpressionAnalyzer::makeSet(const ASTFunction * node, const Block & sample_
         }
 
         subquery_for_set.set = set;
-        prepared_sets[arg.get()] = set;
+        prepared_sets[arg->range] = set;
     }
     else
     {
@@ -1712,7 +1712,7 @@ void ExpressionAnalyzer::makeExplicitSet(const ASTFunction * node, const Block &
 
     SetPtr set = std::make_shared<Set>(SizeLimits(settings.max_rows_in_set, settings.max_bytes_in_set, settings.set_overflow_mode));
     set->createFromAST(set_element_types, elements_ast, context, create_ordered_set);
-    prepared_sets[right_arg.get()] = std::move(set);
+    prepared_sets[right_arg->range] = std::move(set);
 }
 
 
@@ -2102,12 +2102,12 @@ void ExpressionAnalyzer::getActionsImpl(const ASTPtr & ast, bool no_subqueries,
                 /// Select the name in the next cycle.
                 argument_names.emplace_back();
             }
-            else if (prepared_sets.count(child.get()) && functionIsInOrGlobalInOperator(node->name) && arg == 1)
+            else if (prepared_sets.count(child->range) && functionIsInOrGlobalInOperator(node->name) && arg == 1)
             {
                 ColumnWithTypeAndName column;
                 column.type = std::make_shared<DataTypeSet>();
 
-                const SetPtr & set = prepared_sets[child.get()];
+                const SetPtr & set = prepared_sets[child->range];
 
                 /// If the argument is a set given by an enumeration of values (so, the set was already built), give it a unique name,
                 ///  so that sets with the same literal representation do not fuse together (they can have different types).

dbms/src/Interpreters/ExpressionAnalyzer.h

@@ -3,9 +3,9 @@
 #include <Interpreters/AggregateDescription.h>
 #include <Interpreters/Settings.h>
 #include <Core/Block.h>
-#include "ExpressionActions.h"
-#include "ProjectionManipulation.h"
-
+#include <Interpreters/ExpressionActions.h>
+#include <Interpreters/ProjectionManipulation.h>
+#include <Parsers/StringRange.h>
 
 namespace DB
 {
@@ -23,7 +23,9 @@ using ASTPtr = std::shared_ptr<IAST>;
 
 class Set;
 using SetPtr = std::shared_ptr<Set>;
-using PreparedSets = std::unordered_map<IAST*, SetPtr>;
+/// Will compare sets by their position in query string. It's possible because IAST::clone() doesn't chane IAST::range.
+/// It should be taken into account when we want to change AST part which contains sets.
+using PreparedSets = std::unordered_map<StringRange, SetPtr, StringRangePointersHash, StringRangePointersEqualTo>;
 
 class IBlockInputStream;
 using BlockInputStreamPtr = std::shared_ptr<IBlockInputStream>;

dbms/src/Interpreters/InterpreterAlterQuery.cpp

@@ -72,8 +72,16 @@ BlockIO InterpreterAlterQuery::execute()
                 table->attachPartition(command.partition, command.part, context);
                 break;
 
+            case PartitionCommand::REPLACE_PARTITION:
+                {
+                    String from_database = command.from_database.empty() ? context.getCurrentDatabase() : command.from_database;
+                    auto from_storage = context.getTable(from_database, command.from_table);
+                    table->replacePartitionFrom(from_storage, command.partition, command.replace, context);
+                }
+                break;
+
             case PartitionCommand::FETCH_PARTITION:
-                table->fetchPartition(command.partition, command.from, context);
+                table->fetchPartition(command.partition, command.from_zookeeper_path, context);
                 break;
 
             case PartitionCommand::FREEZE_PARTITION:
@@ -187,6 +195,11 @@ void InterpreterAlterQuery::parseAlter(
         {
             out_partition_commands.emplace_back(PartitionCommand::attachPartition(params.partition, params.part));
         }
+        else if (params.type == ASTAlterQuery::REPLACE_PARTITION)
+        {
+            out_partition_commands.emplace_back(
+                PartitionCommand::replacePartition(params.partition, params.replace, params.from_database, params.from_table));
+        }
         else if (params.type == ASTAlterQuery::FETCH_PARTITION)
         {
             out_partition_commands.emplace_back(PartitionCommand::fetchPartition(params.partition, params.from));

dbms/src/Interpreters/InterpreterAlterQuery.h

@@ -28,6 +28,7 @@ private:
         {
             DROP_PARTITION,
             ATTACH_PARTITION,
+            REPLACE_PARTITION,
             FETCH_PARTITION,
             FREEZE_PARTITION,
             CLEAR_COLUMN,
@@ -37,11 +38,20 @@ private:
 
         ASTPtr partition;
         Field column_name;
-        bool detach = false; /// true for DETACH PARTITION.
 
+        /// true for DETACH PARTITION.
+        bool detach = false;
+
+        /// true for ATTACH PART (and false for PARTITION)
         bool part = false;
 
-        String from; /// For FETCH PARTITION - path in ZK to the shard, from which to download the partition.
+        /// For ATTACH PARTITION partition FROM db.table
+        String from_database;
+        String from_table;
+        bool replace = true;
+
+        /// For FETCH PARTITION - path in ZK to the shard, from which to download the partition.
+        String from_zookeeper_path;
 
         /// For FREEZE PARTITION
         String with_name;
@@ -73,12 +83,23 @@ private:
             return res;
         }
 
+        static PartitionCommand replacePartition(const ASTPtr & partition, bool replace, const String & from_database, const String & from_table)
+        {
+            PartitionCommand res;
+            res.type = REPLACE_PARTITION;
+            res.partition = partition;
+            res.replace = replace;
+            res.from_database = from_database;
+            res.from_table = from_table;
+            return res;
+        }
+
         static PartitionCommand fetchPartition(const ASTPtr & partition, const String & from)
         {
             PartitionCommand res;
             res.type = FETCH_PARTITION;
             res.partition = partition;
-            res.from = from;
+            res.from_zookeeper_path = from;
             return res;
         }
 

dbms/src/Interpreters/InterpreterSystemQuery.cpp

@@ -1,10 +1,21 @@
 #include <Interpreters/InterpreterSystemQuery.h>
 #include <Common/DNSResolver.h>
+#include <Common/ActionLock.h>
+#include <Common/typeid_cast.h>
+#include <Common/DNSResolver.h>
+#include <common/ThreadPool.h>
 #include <Interpreters/Context.h>
 #include <Interpreters/ExternalDictionaries.h>
 #include <Interpreters/EmbeddedDictionaries.h>
+#include <Interpreters/ActionLocksManager.h>
+#include <Interpreters/InterpreterDropQuery.h>
+#include <Interpreters/InterpreterCreateQuery.h>
+#include <Databases/IDatabase.h>
+#include <Storages/StorageReplicatedMergeTree.h>
+#include <Storages/StorageFactory.h>
 #include <Parsers/ASTSystemQuery.h>
-#include <Common/typeid_cast.h>
+#include <Parsers/ASTDropQuery.h>
+#include <Parsers/ASTCreateQuery.h>
 #include <csignal>
 
 
@@ -20,6 +31,15 @@ namespace ErrorCodes
 }
 
 
+namespace ActionLocks
+{
+    extern StorageActionBlockType PartsMerge;
+    extern StorageActionBlockType PartsFetch;
+    extern StorageActionBlockType PartsSend;
+    extern StorageActionBlockType ReplicationQueue;
+}
+
+
 namespace
 {
 
@@ -50,11 +70,34 @@ ExecutionStatus getOverallExecutionStatusOfCommands(Callable && command, Callabl
     return ExecutionStatus(res_status, res_message);
 }
 
+/// Implements SYSTEM [START|STOP] <something action from ActionLocks>
+void startStopAction(Context & context, ASTSystemQuery & query, StorageActionBlockType action_type, bool start)
+{
+    auto manager = context.getActionLocksManager();
+    manager->cleanExpired();
+
+    if (!query.target_table.empty())
+    {
+        String database = !query.target_database.empty() ? query.target_database : context.getCurrentDatabase();
+
+        if (start)
+            manager->remove(database, query.target_table, action_type);
+        else
+            manager->add(database, query.target_table, action_type);
+    }
+    else
+    {
+        if (start)
+            manager->remove(action_type);
+        else
+            manager->add(action_type);
+    }
+}
 }
 
 
 InterpreterSystemQuery::InterpreterSystemQuery(const ASTPtr & query_ptr_, Context & context_)
-        : query_ptr(query_ptr_), context(context_) {}
+        : query_ptr(query_ptr_->clone()), context(context_), log(&Poco::Logger::get("InterpreterSystemQuery")) {}
 
 
 BlockIO InterpreterSystemQuery::execute()
@@ -67,6 +110,10 @@ BlockIO InterpreterSystemQuery::execute()
     Context system_context = context.getGlobalContext();
     system_context.setSetting("profile", context.getSystemProfileName());
 
+    /// Make canonical query for simpler processing
+    if (!query.target_table.empty() && query.target_database.empty())
+         query.target_database = context.getCurrentDatabase();
+
     switch (query.type)
     {
         case Type::SHUTDOWN:
@@ -107,14 +154,43 @@ BlockIO InterpreterSystemQuery::execute()
         case Type::RELOAD_CONFIG:
             system_context.reloadConfig();
             break;
+        case Type::STOP_MERGES:
+            startStopAction(context, query, ActionLocks::PartsMerge, false);
+            break;
+        case Type::START_MERGES:
+            startStopAction(context, query, ActionLocks::PartsMerge, true);
+            break;
+        case Type::STOP_FETCHES:
+            startStopAction(context, query, ActionLocks::PartsFetch, false);
+            break;
+        case Type::START_FETCHES:
+            startStopAction(context, query, ActionLocks::PartsFetch, true);
+            break;
+        case Type::STOP_REPLICATED_SENDS:
+            startStopAction(context, query, ActionLocks::PartsSend, false);
+            break;
+        case Type::START_REPLICATEDS_SENDS:
+            startStopAction(context, query, ActionLocks::PartsSend, false);
+            break;
+        case Type::STOP_REPLICATION_QUEUES:
+            startStopAction(context, query, ActionLocks::ReplicationQueue, false);
+            break;
+        case Type::START_REPLICATION_QUEUES:
+            startStopAction(context, query, ActionLocks::ReplicationQueue, true);
+            break;
+        case Type::SYNC_REPLICA:
+            syncReplica(query);
+            break;
+        case Type::RESTART_REPLICAS:
+            restartReplicas(system_context);
+            break;
+        case Type::RESTART_REPLICA:
+            if (!tryRestartReplica(query.target_database, query.target_table, system_context))
+                throw Exception("There is no " + query.target_database + "." + query.target_table + " replicated table",
+                                ErrorCodes::BAD_ARGUMENTS);
+            break;
         case Type::STOP_LISTEN_QUERIES:
         case Type::START_LISTEN_QUERIES:
-        case Type::RESTART_REPLICAS:
-        case Type::SYNC_REPLICA:
-        case Type::STOP_MERGES:
-        case Type::START_MERGES:
-        case Type::STOP_REPLICATION_QUEUES:
-        case Type::START_REPLICATION_QUEUES:
             throw Exception(String(ASTSystemQuery::typeToString(query.type)) + " is not supported yet", ErrorCodes::NOT_IMPLEMENTED);
         default:
             throw Exception("Unknown type of SYSTEM query", ErrorCodes::BAD_ARGUMENTS);
@@ -124,4 +200,92 @@ BlockIO InterpreterSystemQuery::execute()
 }
 
 
+StoragePtr InterpreterSystemQuery::tryRestartReplica(const String & database_name, const String & table_name, Context & context)
+{
+    auto database = context.getDatabase(database_name);
+    auto table_ddl_guard = context.getDDLGuard(database_name, table_name, "Table " + database_name + "." + table_name + " is restarting right now");
+    ASTPtr create_ast;
+
+    /// Detach actions
+    {
+        auto table = context.tryGetTable(database_name, table_name);
+
+        if (!table || !dynamic_cast<const StorageReplicatedMergeTree *>(table.get()))
+            return nullptr;
+
+        table->shutdown();
+
+        /// If table was already dropped by anyone, an exception will be thrown
+        auto table_lock = table->lockForAlter(__PRETTY_FUNCTION__);
+        create_ast = context.getCreateTableQuery(database_name, table_name);
+
+        database->detachTable(table_name);
+    }
+
+    /// Attach actions
+    {
+        /// getCreateTableQuery must return canonical CREATE query representation, there are no need for AST postprocessing
+        auto & create = typeid_cast<ASTCreateQuery &>(*create_ast);
+        create.attach = true;
+
+        std::string data_path = database->getDataPath();
+        auto columns = InterpreterCreateQuery::getColumnsDescription(*create.columns, context);
+
+        StoragePtr table = StorageFactory::instance().get(create,
+            data_path,
+            table_name,
+            database_name,
+            context,
+            context.getGlobalContext(),
+            columns,
+            create.attach,
+            false);
+
+        database->createTable(context, table_name, table, create_ast);
+
+        table->startup();
+        return table;
+    }
+}
+
+void InterpreterSystemQuery::restartReplicas(Context & context)
+{
+    std::vector<std::pair<String, String>> replica_names;
+
+    for (auto & elem : context.getDatabases())
+    {
+        DatabasePtr & database = elem.second;
+        const String & database_name = elem.first;
+
+        for (auto iterator = database->getIterator(context); iterator->isValid(); iterator->next())
+        {
+            if (dynamic_cast<const StorageReplicatedMergeTree *>(iterator->table().get()))
+                replica_names.emplace_back(database_name, iterator->name());
+        }
+    }
+
+    if (replica_names.empty())
+        return;
+
+    ThreadPool pool(std::min(getNumberOfPhysicalCPUCores(), replica_names.size()));
+    for (auto & table : replica_names)
+        pool.schedule([&] () { tryRestartReplica(table.first, table.second, context); });
+    pool.wait();
+}
+
+void InterpreterSystemQuery::syncReplica(ASTSystemQuery & query)
+{
+    String database_name = !query.target_database.empty() ? query.target_database : context.getCurrentDatabase();
+    const String & table_name = query.target_table;
+
+    StoragePtr table = context.getTable(database_name, table_name);
+
+    auto table_replicated = dynamic_cast<StorageReplicatedMergeTree *>(table.get());
+    if (!table_replicated)
+        throw Exception("Table " + database_name + "." + table_name + " is not replicated", ErrorCodes::BAD_ARGUMENTS);
+
+    table_replicated->waitForShrinkingQueueSize(0, context.getSettingsRef().receive_timeout.value.milliseconds());
+}
+
+
 }

dbms/src/Interpreters/InterpreterSystemQuery.h

@@ -7,7 +7,10 @@ namespace DB
 
 class Context;
 class IAST;
+class ASTSystemQuery;
+class IStorage;
 using ASTPtr = std::shared_ptr<IAST>;
+using StoragePtr = std::shared_ptr<IStorage>;
 
 
 class InterpreterSystemQuery : public IInterpreter
@@ -20,6 +23,14 @@ public:
 private:
     ASTPtr query_ptr;
     Context & context;
+    Poco::Logger * log = nullptr;
+
+    /// Tries to get a replicated table and restart it
+    /// Returns pointer to a newly created table if the restart was successful
+    StoragePtr tryRestartReplica(const String & database_name, const String & table_name, Context & context);
+
+    void restartReplicas(Context & context);
+    void syncReplica(ASTSystemQuery & query);
 };
 
 

dbms/src/Interpreters/InterserverIOHandler.h

@@ -85,25 +85,27 @@ public:
     void addEndpoint(const String & name, InterserverIOEndpointPtr endpoint)
     {
         std::lock_guard<std::mutex> lock(mutex);
-        if (endpoint_map.count(name))
+        bool inserted = endpoint_map.try_emplace(name, std::move(endpoint)).second;
+        if (!inserted)
             throw Exception("Duplicate interserver IO endpoint: " + name, ErrorCodes::DUPLICATE_INTERSERVER_IO_ENDPOINT);
-        endpoint_map[name] = std::move(endpoint);
     }
 
     void removeEndpoint(const String & name)
     {
         std::lock_guard<std::mutex> lock(mutex);
-        if (!endpoint_map.count(name))
+        if (!endpoint_map.erase(name))
             throw Exception("No interserver IO endpoint named " + name, ErrorCodes::NO_SUCH_INTERSERVER_IO_ENDPOINT);
-        endpoint_map.erase(name);
     }
 
     InterserverIOEndpointPtr getEndpoint(const String & name)
+    try
     {
         std::lock_guard<std::mutex> lock(mutex);
-        if (!endpoint_map.count(name))
-            throw Exception("No interserver IO endpoint named " + name, ErrorCodes::NO_SUCH_INTERSERVER_IO_ENDPOINT);
-        return endpoint_map[name];
+        return endpoint_map.at(name);
+    }
+    catch (...)
+    {
+        throw Exception("No interserver IO endpoint named " + name, ErrorCodes::NO_SUCH_INTERSERVER_IO_ENDPOINT);
     }
 
 private:
@@ -129,22 +131,18 @@ public:
     }
 
     ~InterserverIOEndpointHolder()
+    try
     {
-        try
-        {
-            handler.removeEndpoint(name);
-            /// After destroying the object, `endpoint` can still live, since its ownership is acquired during the processing of the request,
-            /// see InterserverIOHTTPHandler.cpp
-        }
-        catch (...)
-        {
-            tryLogCurrentException("~InterserverIOEndpointHolder");
-        }
+        handler.removeEndpoint(name);
+        /// After destroying the object, `endpoint` can still live, since its ownership is acquired during the processing of the request,
+        /// see InterserverIOHTTPHandler.cpp
+    }
+    catch (...)
+    {
+        tryLogCurrentException("~InterserverIOEndpointHolder");
     }
 
     ActionBlocker & getBlocker() { return endpoint->blocker; }
-    void cancelForever() { getBlocker().cancelForever(); }
-    ActionBlocker::LockHolder cancel() { return getBlocker().cancel(); }
 
 private:
     String name;

dbms/src/Interpreters/PartLog.cpp

@@ -88,33 +88,45 @@ void PartLogElement::appendToBlock(Block & block) const
 }
 
 
-bool PartLog::addNewPartToTheLog(Context & context, const MergeTreeDataPart & part, UInt64 elapsed_ns, const ExecutionStatus & execution_status)
+bool PartLog::addNewPart(Context & context, const MutableDataPartPtr & part, UInt64 elapsed_ns, const ExecutionStatus & execution_status)
 {
+    return addNewParts(context, {part}, elapsed_ns, execution_status);
+}
+
+bool PartLog::addNewParts(Context & context, const PartLog::MutableDataPartsVector & parts, UInt64 elapsed_ns,
+                          const ExecutionStatus & execution_status)
+{
+    if (parts.empty())
+        return true;
+
     PartLog * part_log = nullptr;
 
     try
     {
-        part_log = context.getPartLog(part.storage.getDatabaseName());
+        part_log = context.getPartLog(parts.front()->storage.getDatabaseName()); // assume parts belong to the same table
         if (!part_log)
             return false;
 
-        PartLogElement elem;
+        for (const auto & part : parts)
+        {
+            PartLogElement elem;
 
-        elem.event_type = PartLogElement::NEW_PART;
-        elem.event_time = time(nullptr);
-        elem.duration_ms = elapsed_ns / 1000000;
+            elem.event_type = PartLogElement::NEW_PART;
+            elem.event_time = time(nullptr);
+            elem.duration_ms = elapsed_ns / 1000000;
 
-        elem.database_name = part.storage.getDatabaseName();
-        elem.table_name = part.storage.getTableName();
-        elem.part_name = part.name;
+            elem.database_name = part->storage.getDatabaseName();
+            elem.table_name = part->storage.getTableName();
+            elem.part_name = part->name;
 
-        elem.bytes_compressed_on_disk = part.bytes_on_disk;
-        elem.rows = part.rows_count;
+            elem.bytes_compressed_on_disk = part->bytes_on_disk;
+            elem.rows = part->rows_count;
 
-        elem.error = static_cast<UInt16>(execution_status.code);
-        elem.exception = execution_status.message;
+            elem.error = static_cast<UInt16>(execution_status.code);
+            elem.exception = execution_status.message;
 
-        part_log->add(elem);
+            part_log->add(elem);
+        }
     }
     catch (...)
     {

dbms/src/Interpreters/PartLog.h

@@ -55,10 +55,15 @@ class PartLog : public SystemLog<PartLogElement>
 {
     using SystemLog<PartLogElement>::SystemLog;
 
+    using MutableDataPartPtr = std::shared_ptr<MergeTreeDataPart>;
+    using MutableDataPartsVector = std::vector<MutableDataPartPtr>;
+
 public:
     /// Add a record about creation of new part.
-    static bool addNewPartToTheLog(Context & context, const MergeTreeDataPart & part, UInt64 elapsed_ns,
-                                   const ExecutionStatus & execution_status = {});
+    static bool addNewPart(Context & context, const MutableDataPartPtr & part, UInt64 elapsed_ns,
+                           const ExecutionStatus & execution_status = {});
+    static bool addNewParts(Context & context, const MutableDataPartsVector & parts, UInt64 elapsed_ns,
+                            const ExecutionStatus & execution_status = {});
 };
 
 }

dbms/src/Interpreters/Settings.h

@@ -49,6 +49,7 @@ struct Settings
     M(SettingBool, use_uncompressed_cache, true, "Whether to use the cache of uncompressed blocks.") \
     M(SettingBool, replace_running_query, false, "Whether the running request should be canceled with the same id as the new one.") \
     M(SettingUInt64, background_pool_size, DBMS_DEFAULT_BACKGROUND_POOL_SIZE, "Number of threads performing background work for tables (for example, merging in merge tree). Only has meaning at server startup.") \
+    M(SettingUInt64, background_schedule_pool_size, DBMS_DEFAULT_BACKGROUND_POOL_SIZE, "Number of threads performing background tasks for replicated tables. Only has meaning at server startup.") \
     \
     M(SettingMilliseconds, distributed_directory_monitor_sleep_time_ms, DBMS_DISTRIBUTED_DIRECTORY_MONITOR_SLEEP_TIME_MS, "Sleep time for StorageDistributed DirectoryMonitors in case there is no work or exception has been thrown.") \
     \

dbms/src/Interpreters/convertFieldToType.cpp

@@ -72,10 +72,10 @@ static Field convertNumericType(const Field & from, const IDataType & type)
 }
 
 
-DayNum_t stringToDate(const String & s)
+DayNum stringToDate(const String & s)
 {
     ReadBufferFromString in(s);
-    DayNum_t date{};
+    DayNum date{};
 
     readDateText(date, in);
     if (!in.eof())

dbms/src/Parsers/ASTAlterQuery.cpp

@@ -135,6 +135,19 @@ void ASTAlterQuery::formatQueryImpl(const FormatSettings & settings, FormatState
                 << (p.part ? "PART " : "PARTITION ") << (settings.hilite ? hilite_none : "");
             p.partition->formatImpl(settings, state, frame);
         }
+        else if (p.type == ASTAlterQuery::REPLACE_PARTITION)
+        {
+            settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << (p.replace ? "REPLACE" : "ATTACH") << " PARTITION "
+                << (settings.hilite ? hilite_none : "");
+            p.partition->formatImpl(settings, state, frame);
+            settings.ostr << (settings.hilite ? hilite_keyword : "") << " FROM " << (settings.hilite ? hilite_none : "");
+            if (!p.from_database.empty())
+            {
+                settings.ostr << (settings.hilite ? hilite_identifier : "") << backQuoteIfNeed(p.from_database)
+                              << (settings.hilite ? hilite_none : "") << ".";
+            }
+            settings.ostr << (settings.hilite ? hilite_identifier : "") << backQuoteIfNeed(p.from_table) << (settings.hilite ? hilite_none : "");
+        }
         else if (p.type == ASTAlterQuery::FETCH_PARTITION)
         {
             settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << "FETCH "

dbms/src/Parsers/ASTAlterQuery.h

@@ -28,6 +28,7 @@ public:
 
         DROP_PARTITION,
         ATTACH_PARTITION,
+        REPLACE_PARTITION,
         FETCH_PARTITION,
         FREEZE_PARTITION,
 
@@ -57,7 +58,8 @@ public:
           */
         ASTPtr primary_key;
 
-        /** In DROP PARTITION and RESHARD PARTITION queries, the value or ID of the partition is stored here.
+        /** Used in DROP PARTITION, RESHARD PARTITION and ATTACH PARTITION FROM queries.
+         *  The value or ID of the partition is stored here.
           */
         ASTPtr partition;
 
@@ -80,6 +82,12 @@ public:
           */
         String with_name;
 
+        /// REPLACE(ATTACH) PARTITION partition FROM db.table
+        String from_database;
+        String from_table;
+        /// To distinguish REPLACE and ATTACH PARTITION partition FROM db.table
+        bool replace = true;
+
         /// deep copy
         void clone(Parameters & p) const;
     };

dbms/src/Parsers/ASTAsterisk.h

@@ -10,7 +10,12 @@ class ASTAsterisk : public IAST
 {
 public:
     String getID() const override { return "Asterisk"; }
-    ASTPtr clone() const override { return std::make_shared<ASTAsterisk>(*this); }
+    ASTPtr clone() const override
+    {
+        auto clone = std::make_shared<ASTAsterisk>(*this);
+        clone->cloneChildren();
+        return std::move(clone);
+    }
     String getColumnName() const override { return "*"; }
 
 protected:

dbms/src/Parsers/ASTExpressionList.cpp

@@ -6,13 +6,9 @@ namespace DB
 
 ASTPtr ASTExpressionList::clone() const
 {
-    const auto res = std::make_shared<ASTExpressionList>(*this);
-    res->children.clear();
-
-    for (const auto & child : children)
-        res->children.emplace_back(child->clone());
-
-    return res;
+    auto clone = std::make_shared<ASTExpressionList>(*this);
+    clone->cloneChildren();
+    return std::move(clone);
 }
 
 void ASTExpressionList::formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const

dbms/src/Parsers/ASTIdentifier.h

@@ -26,7 +26,7 @@ public:
     Kind kind;
 
     ASTIdentifier(const String & name_, const Kind kind_ = Column)
-        : name(name_), kind(kind_) {}
+        : name(name_), kind(kind_) { range = StringRange(name.data(), name.data() + name.size()); }
 
     /** Get the text that identifies this element. */
     String getID() const override { return "Identifier_" + name; }

dbms/src/Parsers/ASTKillQueryQuery.h

@@ -11,7 +11,13 @@ public:
     bool sync = false;          // SYNC or ASYNC mode
     bool test = false;          // does it TEST mode? (doesn't cancel queries just checks and shows them)
 
-    ASTPtr clone() const override { return std::make_shared<ASTKillQueryQuery>(*this); }
+    ASTPtr clone() const override
+    {
+        auto clone = std::make_shared<ASTKillQueryQuery>(*this);
+        clone->where_expression = where_expression->clone();
+        clone->children = {clone->where_expression};
+        return std::move(clone);
+    }
 
     String getID() const override;
 

dbms/src/Parsers/ASTOrderByElement.h

@@ -5,14 +5,13 @@
 
 namespace DB
 {
-
 /** Element of expression with ASC or DESC,
   *  and possibly with COLLATE.
   */
 class ASTOrderByElement : public IAST
 {
 public:
-    int direction;    /// 1 for ASC, -1 for DESC
+    int direction; /// 1 for ASC, -1 for DESC
     int nulls_direction; /// Same as direction for NULLS LAST, opposite for NULLS FIRST.
     bool nulls_direction_was_explicitly_specified;
 
@@ -20,21 +19,27 @@ public:
     ASTPtr collation;
 
     ASTOrderByElement(
-        const int direction_,
-        const int nulls_direction_,
-        const bool nulls_direction_was_explicitly_specified_,
-        ASTPtr & collation_)
-        :
-        direction(direction_), nulls_direction(nulls_direction_),
-        nulls_direction_was_explicitly_specified(nulls_direction_was_explicitly_specified_),
-        collation(collation_) {}
+        const int direction_, const int nulls_direction_, const bool nulls_direction_was_explicitly_specified_, ASTPtr & collation_)
+        : direction(direction_)
+        , nulls_direction(nulls_direction_)
+        , nulls_direction_was_explicitly_specified(nulls_direction_was_explicitly_specified_)
+        , collation(collation_)
+    {
+    }
 
-    String getID() const override { return "OrderByElement"; }
+    String getID() const override
+    {
+        return "OrderByElement";
+    }
 
-    ASTPtr clone() const override { return std::make_shared<ASTOrderByElement>(*this); }
+    ASTPtr clone() const override
+    {
+        auto clone = std::make_shared<ASTOrderByElement>(*this);
+        clone->cloneChildren();
+        return std::move(clone);
+    }
 
 protected:
     void formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override;
 };
-
 }

dbms/src/Parsers/ASTQualifiedAsterisk.h

@@ -13,7 +13,12 @@ class ASTQualifiedAsterisk : public IAST
 {
 public:
     String getID() const override { return "QualifiedAsterisk"; }
-    ASTPtr clone() const override { return std::make_shared<ASTQualifiedAsterisk>(*this); }
+    ASTPtr clone() const override
+    {
+        auto clone = std::make_shared<ASTQualifiedAsterisk>(*this);
+        clone->cloneChildren();
+        return std::move(clone);
+    }
     String getColumnName() const override;
 
 protected:

dbms/src/Parsers/ASTSystemQuery.cpp

@@ -33,6 +33,8 @@ const char * ASTSystemQuery::typeToString(Type type)
             return "START LISTEN QUERIES";
         case Type::RESTART_REPLICAS:
             return "RESTART REPLICAS";
+        case Type::RESTART_REPLICA:
+            return "RESTART REPLICA";
         case Type::SYNC_REPLICA:
             return "SYNC REPLICA";
         case Type::RELOAD_DICTIONARY:
@@ -47,6 +49,14 @@ const char * ASTSystemQuery::typeToString(Type type)
             return "STOP MERGES";
         case Type::START_MERGES:
             return "START MERGES";
+        case Type::STOP_FETCHES:
+            return "STOP FETCHES";
+        case Type::START_FETCHES:
+            return "START FETCHES";
+        case Type::STOP_REPLICATED_SENDS:
+            return "STOP REPLICATED SENDS";
+        case Type::START_REPLICATEDS_SENDS:
+            return "START REPLICATED SENDS";
         case Type::STOP_REPLICATION_QUEUES:
             return "STOP REPLICATION QUEUES";
         case Type::START_REPLICATION_QUEUES:
@@ -62,10 +72,38 @@ void ASTSystemQuery::formatImpl(const FormatSettings & settings, FormatState &,
     settings.ostr << (settings.hilite ? hilite_keyword : "") << "SYSTEM " << (settings.hilite ? hilite_none : "");
     settings.ostr << typeToString(type);
 
-    if (type == Type::RELOAD_DICTIONARY)
+    auto print_database_table = [&] ()
+    {
+        settings.ostr << " ";
+
+        if (!target_database.empty())
+        {
+            settings.ostr << (settings.hilite ? hilite_identifier : "") << backQuoteIfNeed(target_database)
+                          << (settings.hilite ? hilite_none : "") << ".";
+        }
+
+        settings.ostr << (settings.hilite ? hilite_identifier : "") << backQuoteIfNeed(target_table)
+                      << (settings.hilite ? hilite_none : "");
+    };
+
+    if (   type == Type::STOP_MERGES
+        || type == Type::START_MERGES
+        || type == Type::STOP_FETCHES
+        || type == Type::START_FETCHES
+        || type == Type::STOP_REPLICATED_SENDS
+        || type == Type::START_REPLICATEDS_SENDS
+        || type == Type::STOP_REPLICATION_QUEUES
+        || type == Type::START_REPLICATION_QUEUES)
+    {
+        if (!target_table.empty())
+            print_database_table();
+    }
+    else if (type == Type::RESTART_REPLICA || type == Type::SYNC_REPLICA)
+    {
+        print_database_table();
+    }
+    else if (type == Type::RELOAD_DICTIONARY)
         settings.ostr << " " << backQuoteIfNeed(target_dictionary);
-    else if (type == Type::SYNC_REPLICA)
-        throw Exception("SYNC_REPLICA isn't supported yet", ErrorCodes::NOT_IMPLEMENTED);
 }
 
 

dbms/src/Parsers/ASTSystemQuery.h

@@ -21,6 +21,7 @@ public:
         STOP_LISTEN_QUERIES,
         START_LISTEN_QUERIES,
         RESTART_REPLICAS,
+        RESTART_REPLICA,
         SYNC_REPLICA,
         RELOAD_DICTIONARY,
         RELOAD_DICTIONARIES,
@@ -28,6 +29,10 @@ public:
         RELOAD_CONFIG,
         STOP_MERGES,
         START_MERGES,
+        STOP_FETCHES,
+        START_FETCHES,
+        STOP_REPLICATED_SENDS,
+        START_REPLICATEDS_SENDS,
         STOP_REPLICATION_QUEUES,
         START_REPLICATION_QUEUES,
         END
@@ -38,8 +43,8 @@ public:
     Type type = Type::UNKNOWN;
 
     String target_dictionary;
-    //String target_replica_database;
-    //String target_replica_table;
+    String target_database;
+    String target_table;
 
     String getID() const override { return "SYSTEM query"; };
 

dbms/src/Parsers/IAST.cpp

@@ -94,4 +94,11 @@ size_t IAST::checkDepthImpl(size_t max_depth, size_t level) const
     return res;
 }
 
+
+void IAST::cloneChildren()
+{
+    for (auto & child : children)
+        child = child->clone();
+}
+
 }

dbms/src/Parsers/IAST.h

@@ -65,7 +65,7 @@ public:
 
     ASTPtr ptr() { return shared_from_this(); }
 
-    /** Get a deep copy of the tree. */
+    /** Get a deep copy of the tree. Cloned object must have the same range. */
     virtual ASTPtr clone() const = 0;
 
     /** Get hash code, identifying this element and its subtree.
@@ -192,6 +192,8 @@ public:
 
     void writeAlias(const String & name, std::ostream & s, bool hilite) const;
 
+    void cloneChildren();
+
 public:
     /// For syntax highlighting.
     static const char * hilite_keyword;

dbms/src/Parsers/ParserAlterQuery.cpp

@@ -6,6 +6,8 @@
 #include <Parsers/ASTIdentifier.h>
 #include <Parsers/ASTAlterQuery.h>
 #include <Parsers/ASTLiteral.h>
+#include <Parsers/parseDatabaseAndTableName.h>
+
 
 namespace DB
 {
@@ -45,8 +47,6 @@ bool ParserAlterQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
     ParserStringLiteral parser_string_literal;
     ParserExpression exp_elem;
 
-    ASTPtr table;
-    ASTPtr database;
     String cluster_str;
     ASTPtr col_type;
     ASTPtr col_after;
@@ -57,24 +57,9 @@ bool ParserAlterQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
     if (!s_alter_table.ignore(pos, expected))
         return false;
 
-    if (!table_parser.parse(pos, database, expected))
+    if (!parseDatabaseAndTableName(pos, expected, query->database, query->table))
         return false;
 
-    /// Parse [db].name
-    if (s_dot.ignore(pos))
-    {
-        if (!table_parser.parse(pos, table, expected))
-            return false;
-
-        query->table = typeid_cast<ASTIdentifier &>(*table).name;
-        query->database = typeid_cast<ASTIdentifier &>(*database).name;
-    }
-    else
-    {
-        table = database;
-        query->table = typeid_cast<ASTIdentifier &>(*table).name;
-    }
-
     if (ParserKeyword{"ON"}.ignore(pos, expected))
     {
         if (!ASTQueryWithOnCluster::parse(pos, cluster_str, expected))
@@ -142,7 +127,32 @@ bool ParserAlterQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
             if (!parser_partition.parse(pos, params.partition, expected))
                 return false;
 
-            params.type = ASTAlterQuery::ATTACH_PARTITION;
+            if (s_from.ignore(pos))
+            {
+                if (!parseDatabaseAndTableName(pos, expected, params.from_database, params.from_table))
+                    return false;
+
+                params.replace = false;
+                params.type = ASTAlterQuery::REPLACE_PARTITION;
+            }
+            else
+            {
+                params.type = ASTAlterQuery::ATTACH_PARTITION;
+            }
+        }
+        else if (ParserKeyword{"REPLACE PARTITION"}.ignore(pos, expected))
+        {
+            if (!parser_partition.parse(pos, params.partition, expected))
+                return false;
+
+            if (!s_from.ignore(pos, expected))
+                return false;
+
+            if (!parseDatabaseAndTableName(pos, expected, params.from_database, params.from_table))
+                return false;
+
+            params.replace = true;
+            params.type = ASTAlterQuery::REPLACE_PARTITION;
         }
         else if (s_attach_part.ignore(pos, expected))
         {

dbms/src/Parsers/ParserKillQueryQuery.cpp

@@ -23,6 +23,8 @@ bool ParserKillQueryQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expect
     if (!p_where_expression.parse(pos, query->where_expression, expected))
         return false;
 
+    query->children.emplace_back(query->where_expression);
+
     if (ParserKeyword{"SYNC"}.ignore(pos))
         query->sync = true;
     else if (ParserKeyword{"ASYNC"}.ignore(pos))

dbms/src/Parsers/ParserSystemQuery.cpp

@@ -2,7 +2,10 @@
 #include <Parsers/ASTSystemQuery.h>
 #include <Parsers/CommonParsers.h>
 #include <Parsers/ASTLiteral.h>
+#include <Parsers/ASTIdentifier.h>
 #include <Parsers/parseIdentifierOrStringLiteral.h>
+#include <Parsers/ExpressionElementParsers.h>
+#include <Parsers/parseDatabaseAndTableName.h>
 #include <Interpreters/evaluateConstantExpression.h>
 
 
@@ -39,14 +42,33 @@ bool ParserSystemQuery::parseImpl(IParser::Pos & pos, ASTPtr & node, Expected &
     if (!found)
         return false;
 
-    if (res->type == Type::RELOAD_DICTIONARY)
+    switch (res->type)
     {
-        if (!parseIdentifierOrStringLiteral(pos, expected, res->target_dictionary))
-            return false;
-    }
-    else if (res->type == Type::SYNC_REPLICA)
-    {
-        throw Exception("SYNC REPLICA is not supported yet", ErrorCodes::NOT_IMPLEMENTED);
+        case Type::RELOAD_DICTIONARY:
+            if (!parseIdentifierOrStringLiteral(pos, expected, res->target_dictionary))
+                return false;
+            break;
+
+        case Type::RESTART_REPLICA:
+        case Type::SYNC_REPLICA:
+            if (!parseDatabaseAndTableName(pos, expected, res->target_database, res->target_table))
+                return false;
+            break;
+
+        case Type::STOP_MERGES:
+        case Type::START_MERGES:
+        case Type::STOP_FETCHES:
+        case Type::START_FETCHES:
+        case Type::STOP_REPLICATED_SENDS:
+        case Type::START_REPLICATEDS_SENDS:
+        case Type::STOP_REPLICATION_QUEUES:
+        case Type::START_REPLICATION_QUEUES:
+            parseDatabaseAndTableName(pos, expected, res->target_database, res->target_table);
+            break;
+
+        default:
+            /// There are no [db.table] after COMMAND NAME
+            break;
     }
 
     node = std::move(res);

dbms/src/Parsers/StringRange.h

@@ -4,6 +4,7 @@
 #include <Parsers/TokenIterator.h>
 #include <map>
 #include <memory>
+#include <Common/SipHash.h>
 
 
 namespace DB
@@ -14,9 +15,10 @@ struct StringRange
     const char * first = nullptr;
     const char * second = nullptr;
 
-    StringRange() {}
+    StringRange() = default;
+    StringRange(const StringRange & other) = default;
     StringRange(const char * begin, const char * end) : first(begin), second(end) {}
-    StringRange(TokenIterator token) : first(token->begin), second(token->end) {}
+    explicit StringRange(TokenIterator token) : first(token->begin), second(token->end) {}
 
     StringRange(TokenIterator token_begin, TokenIterator token_end)
     {
@@ -44,4 +46,27 @@ inline String toString(const StringRange & range)
     return range.first ? String(range.first, range.second) : String();
 }
 
-}
+/// Hashes only the values of pointers in StringRange. Is used with StringRangePointersEqualTo comparator.
+struct StringRangePointersHash
+{
+    UInt64 operator()(const StringRange & range) const
+    {
+        SipHash hash;
+        hash.update(range.first);
+        hash.update(range.second);
+        return hash.get64();
+    }
+};
+
+/// Ranges are equal only when they point to the same memory region.
+/// It may be used when it's enough to compare substrings by their position in the same string.
+struct StringRangePointersEqualTo
+{
+    constexpr bool operator()(const StringRange &lhs, const StringRange &rhs) const
+    {
+        return std::tie(lhs.first, lhs.second) == std::tie(rhs.first, rhs.second);
+    }
+};
+
+};
+

dbms/src/Parsers/parseDatabaseAndTableName.cpp

@@ -0,0 +1,45 @@
+#include "parseDatabaseAndTableName.h"
+#include <Parsers/ExpressionElementParsers.h>
+#include <Parsers/ASTIdentifier.h>
+#include <Parsers/CommonParsers.h>
+#include <Common/typeid_cast.h>
+
+
+namespace DB
+{
+
+bool parseDatabaseAndTableName(IParser::Pos & pos, Expected & expected, String & database_str, String & table_str)
+{
+    ParserToken s_dot(TokenType::Dot);
+    ParserIdentifier table_parser;
+
+    ASTPtr database;
+    ASTPtr table;
+
+    database_str = "";
+    table_str = "";
+
+    if (!table_parser.parse(pos, database, expected))
+        return false;
+
+    if (s_dot.ignore(pos))
+    {
+        if (!table_parser.parse(pos, table, expected))
+        {
+            database_str = "";
+            return false;
+        }
+
+        database_str = typeid_cast<ASTIdentifier &>(*database).name;
+        table_str = typeid_cast<ASTIdentifier &>(*table).name;
+    }
+    else
+    {
+        database_str = "";
+        table_str = typeid_cast<ASTIdentifier &>(*database).name;
+    }
+
+    return true;
+}
+
+}

dbms/src/Parsers/parseDatabaseAndTableName.h

@@ -0,0 +1,10 @@
+#pragma once
+#include <Parsers/IParser.h>
+
+namespace DB
+{
+
+/// Parses [db].name
+bool parseDatabaseAndTableName(IParser::Pos & pos, Expected & expected, String & database_str, String & table_str);
+
+}

dbms/src/Server/Client.cpp

@@ -15,6 +15,7 @@
 #include <Poco/Util/Application.h>
 #include <common/readline_use.h>
 #include <common/find_first_symbols.h>
+#include <common/SetTerminalEcho.h>
 #include <Common/ClickHouseRevision.h>
 #include <Common/Stopwatch.h>
 #include <Common/Exception.h>
@@ -52,6 +53,7 @@
 #include "InterruptListener.h"
 #include <Functions/registerFunctions.h>
 #include <AggregateFunctions/registerAggregateFunctions.h>
+#include <ext/scope_guard.h>
 
 
 /// http://en.wikipedia.org/wiki/ANSI_escape_code
@@ -197,7 +199,25 @@ private:
 
             default_database = config.getString("database", "");
             user = config.getString("user", "");
-            password = config.getString("password", "");
+
+            if (config.getBool("ask-password", false))
+            {
+                if (config.has("password"))
+                    throw Exception("Specified both --password and --ask-password. Remove one of them", ErrorCodes::BAD_ARGUMENTS);
+
+                std::cout << "Password for user " << user << ": ";
+                SetTerminalEcho(false);
+
+                SCOPE_EXIT({
+                    SetTerminalEcho(true);
+                });
+                std::getline(std::cin, password);
+                std::cout << std::endl;
+            }
+            else
+            {
+                password = config.getString("password", "");
+            }
 
             compression = config.getBool("compression", true)
                 ? Protocol::Compression::Enable
@@ -461,8 +481,9 @@ private:
             query_id = config().getString("query_id", "");
             nonInteractive();
 
+            /// If exception code isn't zero, we should return non-zero return code anyway.
             if (last_exception)
-                return last_exception->code();
+                return last_exception->code() != 0 ? last_exception->code() : -1;
 
             return 0;
         }
@@ -1364,18 +1385,27 @@ public:
 
         ioctl(0, TIOCGWINSZ, &terminal_size);
 
+        unsigned line_length = boost::program_options::options_description::m_default_line_length;
+        unsigned min_description_length = line_length / 2;
+        if (!stdin_is_not_tty)
+        {
+            line_length = std::max(3U, static_cast<unsigned>(terminal_size.ws_col));
+            min_description_length = std::min(min_description_length, line_length - 2);
+        }
+
 #define DECLARE_SETTING(TYPE, NAME, DEFAULT, DESCRIPTION) (#NAME, boost::program_options::value<std::string> (), DESCRIPTION)
 
         /// Main commandline options related to client functionality and all parameters from Settings.
-        boost::program_options::options_description main_description("Main options", terminal_size.ws_col);
+        boost::program_options::options_description main_description("Main options", line_length, min_description_length);
         main_description.add_options()
             ("help", "produce help message")
             ("config-file,c", boost::program_options::value<std::string>(), "config-file path")
             ("host,h", boost::program_options::value<std::string>()->default_value("localhost"), "server host")
             ("port", boost::program_options::value<int>()->default_value(9000), "server port")
             ("secure,s", "secure")
-            ("user,u", boost::program_options::value<std::string>(), "user")
+            ("user,u", boost::program_options::value<std::string>()->default_value("default"), "user")
             ("password", boost::program_options::value<std::string>(), "password")
+            ("ask-password", "ask-password")
             ("query_id", boost::program_options::value<std::string>(), "query_id")
             ("query,q", boost::program_options::value<std::string>(), "query")
             ("database,d", boost::program_options::value<std::string>(), "database")
@@ -1482,7 +1512,8 @@ public:
             config().setString("user", options["user"].as<std::string>());
         if (options.count("password"))
             config().setString("password", options["password"].as<std::string>());
-
+        if (options.count("ask-password"))
+            config().setBool("ask-password", true);
         if (options.count("multiline"))
             config().setBool("multiline", true);
         if (options.count("multiquery"))

dbms/src/Server/LocalServer.cpp

@@ -388,16 +388,23 @@ std::string LocalServer::getHelpFooter() const
 
 void LocalServer::init(int argc, char ** argv)
 {
+    namespace po = boost::program_options;
+
     /// Don't parse options with Poco library, we prefer neat boost::program_options
     stopOptionsProcessing();
 
-    winsize terminal_size{};
-    ioctl(0, TIOCGWINSZ, &terminal_size);
-
-    namespace po = boost::program_options;
+    unsigned line_length = po::options_description::m_default_line_length;
+    unsigned min_description_length = line_length / 2;
+    if (isatty(STDIN_FILENO))
+    {
+        winsize terminal_size{};
+        ioctl(0, TIOCGWINSZ, &terminal_size);
+        line_length = std::max(3U, static_cast<unsigned>(terminal_size.ws_col));
+        min_description_length = std::min(min_description_length, line_length - 2);
+    }
 
 #define DECLARE_SETTING(TYPE, NAME, DEFAULT, DESCRIPTION) (#NAME, po::value<std::string> (), DESCRIPTION)
-    po::options_description description("Main options", terminal_size.ws_col);
+    po::options_description description("Main options", line_length, min_description_length);
     description.add_options()
         ("help", "produce help message")
         ("config-file,c", po::value<std::string>(), "config-file path")

dbms/src/Storages/Distributed/DistributedBlockOutputStream.cpp

@@ -374,7 +374,8 @@ void DistributedBlockOutputStream::writeSuffix()
             {
                 if (job.stream)
                 {
-                    pool->schedule([&job] () {
+                    pool->schedule([&job] ()
+                    {
                         job.stream->writeSuffix();
                     });
                 }

dbms/src/Storages/IStorage.h

@@ -9,6 +9,7 @@
 #include <shared_mutex>
 #include <memory>
 #include <optional>
+#include <Common/ActionLock.h>
 
 
 namespace DB
@@ -26,6 +27,8 @@ class IBlockOutputStream;
 class RWLockFIFO;
 using RWLockFIFOPtr = std::shared_ptr<RWLockFIFO>;
 
+using StorageActionBlockType = size_t;
+
 using BlockOutputStreamPtr = std::shared_ptr<IBlockOutputStream>;
 using BlockInputStreamPtr = std::shared_ptr<IBlockInputStream>;
 using BlockInputStreams = std::vector<BlockInputStreamPtr>;
@@ -104,6 +107,9 @@ public:
     /** Returns true if the storage replicates SELECT, INSERT and ALTER commands among replicas. */
     virtual bool supportsReplication() const { return false; }
 
+    /** Returns true if the storage supports deduplication of inserted data blocks . */
+    virtual bool supportsDeduplication() const { return false; }
+
     /** Does not allow you to change the structure or name of the table.
       * If you change the data in the table, you will need to specify will_modify_data = true.
       * This will take an extra lock that does not allow starting ALTER MODIFY.
@@ -225,6 +231,12 @@ public:
         throw Exception("Method dropColumnFromPartition is not supported by storage " + getName(), ErrorCodes::NOT_IMPLEMENTED);
     }
 
+    /** Execute ALTER TABLE dst.table REPLACE(ATTACH) PARTITION partition FROM src.table */
+    virtual void replacePartitionFrom(const StoragePtr & /*source_table*/, const ASTPtr & /*partition*/, bool /*replace*/, const Context &)
+    {
+        throw Exception("Method replacePartitionFrom is not supported by storage " + getName(), ErrorCodes::NOT_IMPLEMENTED);
+    }
+
     /** Run the query (DROP|DETACH) PARTITION.
       */
     virtual void dropPartition(const ASTPtr & /*query*/, const ASTPtr & /*partition*/, bool /*detach*/, const Context & /*context*/)
@@ -284,6 +296,13 @@ public:
       */
     virtual void shutdown() {}
 
+    /// Asks table to stop executing some action identified by action_type
+    /// If table does not support such type of lock, and empty lock is returned
+    virtual ActionLock getActionLock(StorageActionBlockType /* action_type */) const
+    {
+        return {};
+    }
+
     bool is_dropped{false};
 
     /// Does table support index for IN sections

dbms/src/Storages/ITableDeclaration.cpp

@@ -198,7 +198,7 @@ void ITableDeclaration::check(const NamesAndTypesList & provided_columns, const
             throw Exception("There is no column with name " + name + ". There are columns: "
                 + listOfColumns(available_columns), ErrorCodes::NO_SUCH_COLUMN_IN_TABLE);
 
-        if (it->second->getName() != jt->second->getName())
+        if (!it->second->equals(*jt->second))
             throw Exception("Type mismatch for column " + name + ". Column has type "
                 + jt->second->getName() + ", got type " + it->second->getName(), ErrorCodes::TYPE_MISMATCH);
 

dbms/src/Storages/MergeTree/ActiveDataPartSet.cpp

@@ -8,22 +8,22 @@ ActiveDataPartSet::ActiveDataPartSet(MergeTreeDataFormatVersion format_version_,
     : format_version(format_version_)
 {
     for (const auto & name : names)
-        addImpl(name);
+        addUnlocked(name);
 }
 
 
 void ActiveDataPartSet::add(const String & name)
 {
     std::lock_guard<std::mutex> lock(mutex);
-    addImpl(name);
+    addUnlocked(name);
 }
 
 
-void ActiveDataPartSet::addImpl(const String & name)
+void ActiveDataPartSet::addUnlocked(const String & name)
 {
     auto part_info = MergeTreePartInfo::fromPartName(name, format_version);
 
-    if (!getContainingPartImpl(part_info).empty())
+    if (!getContainingPartUnlocked(part_info).empty())
         return;
 
     /// Parts contained in `part` are located contiguously in `part_info_to_name`, overlapping with the place where the part itself would be inserted.
@@ -54,11 +54,11 @@ void ActiveDataPartSet::addImpl(const String & name)
 String ActiveDataPartSet::getContainingPart(const String & part_name) const
 {
     std::lock_guard<std::mutex> lock(mutex);
-    return getContainingPartImpl(MergeTreePartInfo::fromPartName(part_name, format_version));
+    return getContainingPartUnlocked(MergeTreePartInfo::fromPartName(part_name, format_version));
 }
 
 
-String ActiveDataPartSet::getContainingPartImpl(const MergeTreePartInfo & part_info) const
+String ActiveDataPartSet::getContainingPartUnlocked(const MergeTreePartInfo & part_info) const
 {
     /// A part can only be covered/overlapped by the previous or next one in `part_info_to_name`.
     auto it = part_info_to_name.lower_bound(part_info);
@@ -79,11 +79,8 @@ String ActiveDataPartSet::getContainingPartImpl(const MergeTreePartInfo & part_i
     return String();
 }
 
-
-Strings ActiveDataPartSet::getParts() const
+Strings ActiveDataPartSet::getPartsUnlocked() const
 {
-    std::lock_guard<std::mutex> lock(mutex);
-
     Strings res;
     res.reserve(part_info_to_name.size());
     for (const auto & kv : part_info_to_name)
@@ -92,6 +89,12 @@ Strings ActiveDataPartSet::getParts() const
     return res;
 }
 
+Strings ActiveDataPartSet::getParts() const
+{
+    std::lock_guard<std::mutex> lock(mutex);
+    return getPartsUnlocked();
+}
+
 
 size_t ActiveDataPartSet::size() const
 {

dbms/src/Storages/MergeTree/ActiveDataPartSet.h

@@ -12,8 +12,7 @@ namespace DB
 
 /** Supports multiple names of active parts of data.
   * Repeats part of the MergeTreeData functionality.
-  * TODO: generalize with MergeTreeData. It is possible to leave this class approximately as is and use it from MergeTreeData.
-  *       Then in MergeTreeData you can make map<String, DataPartPtr> data_parts and all_data_parts.
+  * TODO: generalize with MergeTreeData
   */
 class ActiveDataPartSet
 {
@@ -26,19 +25,21 @@ public:
     /// If not found, returns an empty string.
     String getContainingPart(const String & name) const;
 
-    Strings getParts() const; /// In ascending order of the partition_id and block number.
+    /// Returns parts in ascending order of the partition_id and block number.
+    Strings getParts() const;
 
     size_t size() const;
 
+    /// Do not block mutex.
+    void addUnlocked(const String & name);
+    String getContainingPartUnlocked(const MergeTreePartInfo & part_info) const;
+    Strings getPartsUnlocked() const;
+
 private:
     MergeTreeDataFormatVersion format_version;
 
     mutable std::mutex mutex;
     std::map<MergeTreePartInfo, String> part_info_to_name;
-
-    /// Do not block mutex.
-    void addImpl(const String & name);
-    String getContainingPartImpl(const MergeTreePartInfo & part_info) const;
 };
 
 }

dbms/src/Storages/MergeTree/DataPartsExchange.cpp

@@ -160,7 +160,8 @@ MergeTreeData::MutableDataPartPtr Fetcher::fetchPart(
     const String & host,
     int port,
     const ConnectionTimeouts & timeouts,
-    bool to_detached)
+    bool to_detached,
+    const String & tmp_prefix_)
 {
     Poco::URI uri;
     uri.setScheme("http");
@@ -176,7 +177,9 @@ MergeTreeData::MutableDataPartPtr Fetcher::fetchPart(
     ReadWriteBufferFromHTTP in{uri, Poco::Net::HTTPRequest::HTTP_POST, {}, timeouts};
 
     static const String TMP_PREFIX = "tmp_fetch_";
-    String relative_part_path = String(to_detached ? "detached/" : "") + TMP_PREFIX + part_name;
+    String tmp_prefix = tmp_prefix_.empty() ? TMP_PREFIX : tmp_prefix_;
+
+    String relative_part_path = String(to_detached ? "detached/" : "") + tmp_prefix + part_name;
     String absolute_part_path = data.getFullPath() + relative_part_path + "/";
     Poco::File part_file(absolute_part_path);
 

dbms/src/Storages/MergeTree/DataPartsExchange.h

@@ -54,7 +54,8 @@ public:
         const String & host,
         int port,
         const ConnectionTimeouts & timeouts,
-        bool to_detached = false);
+        bool to_detached = false,
+        const String & tmp_prefix_ = "");
 
     /// You need to stop the data transfer.
     ActionBlocker blocker;

dbms/src/Storages/MergeTree/KeyCondition.cpp

@@ -641,8 +641,8 @@ bool KeyCondition::atomFromAST(const ASTPtr & node, const Context & context, Blo
         bool is_set_const = false;
         bool is_constant_transformed = false;
 
-        if (prepared_sets.count(args[1].get())
-            && isTupleIndexable(args[0], context, out, prepared_sets[args[1].get()], key_column_num))
+        if (prepared_sets.count(args[1]->range)
+            && isTupleIndexable(args[0], context, out, prepared_sets[args[1]->range], key_column_num))
         {
             key_arg_pos = 0;
             is_set_const = true;
@@ -1016,7 +1016,7 @@ bool KeyCondition::mayBeTrueInRangeImpl(const std::vector<Range> & key_ranges, c
         {
             auto in_func = typeid_cast<const ASTFunction *>(element.in_function.get());
             const ASTs & args = typeid_cast<const ASTExpressionList &>(*in_func->arguments).children;
-            PreparedSets::const_iterator it = prepared_sets.find(args[1].get());
+            PreparedSets::const_iterator it = prepared_sets.find(args[1]->range);
             if (in_func && it != prepared_sets.end())
             {
                 rpn_stack.emplace_back(element.set_index->mayBeTrueInRange(key_ranges, data_types));

dbms/src/Storages/MergeTree/MergeTreeBlockOutputStream.cpp

@@ -14,7 +14,7 @@ Block MergeTreeBlockOutputStream::getHeader() const
 
 void MergeTreeBlockOutputStream::write(const Block & block)
 {
-    storage.data.delayInsertIfNeeded();
+    storage.data.delayInsertOrThrowIfNeeded();
 
     auto part_blocks = storage.writer.splitBlockIntoParts(block);
     for (auto & current_block : part_blocks)
@@ -24,7 +24,7 @@ void MergeTreeBlockOutputStream::write(const Block & block)
         MergeTreeData::MutableDataPartPtr part = storage.writer.writeTempPart(current_block);
         storage.data.renameTempPartAndAdd(part, &storage.increment);
 
-        PartLog::addNewPartToTheLog(storage.context, *part, watch.elapsed());
+        PartLog::addNewPart(storage.context, part, watch.elapsed());
 
         /// Initiate async merge - it will be done if it's good time for merge and if there are space in 'background_pool'.
         storage.merge_task_handle->wake();

dbms/src/Storages/MergeTree/MergeTreeData.cpp

@@ -3,6 +3,8 @@
 #include <Storages/MergeTree/MergeTreeBlockInputStream.h>
 #include <Storages/MergeTree/MergedBlockOutputStream.h>
 #include <Storages/MergeTree/checkDataPart.h>
+#include <Storages/StorageMergeTree.h>
+#include <Storages/StorageReplicatedMergeTree.h>
 #include <Storages/AlterCommands.h>
 #include <Parsers/ASTIdentifier.h>
 #include <Parsers/ASTNameTypePair.h>
@@ -11,6 +13,7 @@
 #include <Parsers/ASTPartition.h>
 #include <Parsers/ExpressionListParsers.h>
 #include <Parsers/parseQuery.h>
+#include <Parsers/queryToString.h>
 #include <DataStreams/ExpressionBlockInputStream.h>
 #include <DataStreams/ValuesRowInputStream.h>
 #include <DataStreams/copyData.h>
@@ -36,6 +39,7 @@
 #include <Common/Stopwatch.h>
 #include <Common/typeid_cast.h>
 #include <Common/localBackup.h>
+#include <Interpreters/PartLog.h>
 
 #include <Poco/DirectoryIterator.h>
 
@@ -47,7 +51,6 @@
 #include <typeinfo>
 #include <typeindex>
 #include <optional>
-#include <Interpreters/PartLog.h>
 
 
 namespace ProfileEvents
@@ -70,11 +73,11 @@ namespace ErrorCodes
 {
     extern const int MEMORY_LIMIT_EXCEEDED;
     extern const int SYNTAX_ERROR;
-    extern const int CORRUPTED_DATA;
     extern const int INVALID_PARTITION_VALUE;
     extern const int METADATA_MISMATCH;
     extern const int PART_IS_TEMPORARILY_LOCKED;
     extern const int TOO_MANY_PARTS;
+    extern const int INCOMPATIBLE_COLUMNS;
 }
 
 
@@ -550,7 +553,7 @@ void MergeTreeData::loadDataParts(bool skip_sanity_checks)
     for (auto & part : broken_parts_to_remove)
         part->remove();
     for (auto & part : broken_parts_to_detach)
-        part->renameAddPrefix(true, "");
+        part->renameToDetached("");
 
     /// Delete from the set of current parts those parts that are covered by another part (those parts that
     /// were merged), but that for some reason are still not deleted from the filesystem.
@@ -1367,10 +1370,10 @@ MergeTreeData::DataPartsVector MergeTreeData::getActivePartsToReplace(
     const MergeTreePartInfo & new_part_info,
     const String & new_part_name,
     DataPartPtr & out_covering_part,
-    std::lock_guard<std::mutex> & /* data_parts_lock */) const
+    DataPartsLock & /* data_parts_lock */) const
 {
     /// Parts contained in the part are consecutive in data_parts, intersecting the insertion place for the part itself.
-    auto it_middle = data_parts_by_state_and_info.lower_bound(DataPartStateAndInfo(DataPartState::Committed, new_part_info));
+    auto it_middle = data_parts_by_state_and_info.lower_bound(DataPartStateAndInfo{DataPartState::Committed, new_part_info});
     auto committed_parts_range = getDataPartsStateRange(DataPartState::Committed);
 
     /// Go to the left.
@@ -1435,16 +1438,10 @@ void MergeTreeData::renameTempPartAndAdd(MutableDataPartPtr & part, SimpleIncrem
 }
 
 
-
-MergeTreeData::DataPartsVector MergeTreeData::renameTempPartAndReplace(
-    MutableDataPartPtr & part, SimpleIncrement * increment, Transaction * out_transaction)
+void MergeTreeData::renameTempPartAndReplace(
+    MutableDataPartPtr & part, SimpleIncrement * increment, MergeTreeData::Transaction * out_transaction,
+    std::unique_lock<std::mutex> & lock, DataPartsVector * out_covered_parts)
 {
-    if (out_transaction && out_transaction->data && out_transaction->data != this)
-        throw Exception("The same MergeTreeData::Transaction cannot be used for different tables",
-            ErrorCodes::LOGICAL_ERROR);
-
-    std::lock_guard<std::mutex> lock(data_parts_mutex);
-
     part->assertState({DataPartState::Temporary});
 
     MergeTreePartInfo part_info = part->info;
@@ -1489,7 +1486,7 @@ MergeTreeData::DataPartsVector MergeTreeData::renameTempPartAndReplace(
     if (covering_part)
     {
         LOG_WARNING(log, "Tried to add obsolete part " << part_name << " covered by " << covering_part->getNameWithState());
-        return {};
+        return;
     }
 
     /// All checks are passed. Now we can rename the part on disk.
@@ -1523,12 +1520,48 @@ MergeTreeData::DataPartsVector MergeTreeData::renameTempPartAndReplace(
         addPartContributionToColumnSizes(part);
     }
 
+    if (out_covered_parts)
+    {
+        for (DataPartPtr & covered_part : covered_parts)
+            out_covered_parts->emplace_back(std::move(covered_part));
+    }
+}
+
+MergeTreeData::DataPartsVector MergeTreeData::renameTempPartAndReplace(
+    MutableDataPartPtr & part, SimpleIncrement * increment, Transaction * out_transaction)
+{
+    if (out_transaction && out_transaction->data && out_transaction->data != this)
+    throw Exception("The same MergeTreeData::Transaction cannot be used for different tables",
+        ErrorCodes::LOGICAL_ERROR);
+
+    DataPartsVector covered_parts;
+    {
+        std::unique_lock<std::mutex> lock(data_parts_mutex);
+        renameTempPartAndReplace(part, increment, out_transaction, lock, &covered_parts);
+    }
     return covered_parts;
 }
 
-void MergeTreeData::removePartsFromWorkingSet(const DataPartsVector & remove, bool clear_without_timeout)
+void MergeTreeData::removePartsFromWorkingSet(const MergeTreeData::DataPartsVector & remove, bool clear_without_timeout, DataPartsLock & /*acquired_lock*/)
 {
-    std::lock_guard<std::mutex> lock(data_parts_mutex);
+    auto remove_time = clear_without_timeout ? 0 : time(nullptr);
+
+    for (const DataPartPtr & part : remove)
+    {
+        if (part->state == MergeTreeDataPart::State::Committed)
+            removePartContributionToColumnSizes(part);
+
+        if (part->state == MergeTreeDataPart::State::Committed || clear_without_timeout)
+            part->remove_time.store(remove_time, std::memory_order_relaxed);
+
+        if (part->state != MergeTreeDataPart::State::Outdated)
+            modifyPartState(part, MergeTreeDataPart::State::Outdated);
+    }
+}
+
+void MergeTreeData::removePartsFromWorkingSet(const DataPartsVector & remove, bool clear_without_timeout, DataPartsLock * acquired_lock)
+{
+    auto lock = (acquired_lock) ? DataPartsLock() : lockParts();
 
     for (auto & part : remove)
     {
@@ -1538,37 +1571,83 @@ void MergeTreeData::removePartsFromWorkingSet(const DataPartsVector & remove, bo
         part->assertState({DataPartState::PreCommitted, DataPartState::Committed, DataPartState::Outdated});
     }
 
-    auto remove_time = clear_without_timeout ? 0 : time(nullptr);
-    for (const DataPartPtr & part : remove)
-    {
-        if (part->state == DataPartState::Committed)
-            removePartContributionToColumnSizes(part);
-
-        modifyPartState(part, DataPartState::Outdated);
-        part->remove_time.store(remove_time, std::memory_order_relaxed);
-    }
+    removePartsFromWorkingSet(remove, clear_without_timeout, lock);
 }
 
-
-void MergeTreeData::renameAndDetachPart(const DataPartPtr & part_to_detach, const String & prefix, bool restore_covered,
-                                        bool move_to_detached)
+MergeTreeData::DataPartsVector MergeTreeData::removePartsInRangeFromWorkingSet(const MergeTreePartInfo & drop_range, bool clear_without_timeout,
+                                                                               bool skip_intersecting_parts, DataPartsLock & lock)
 {
-    LOG_INFO(log, "Renaming " << part_to_detach->relative_path << " to " << prefix << part_to_detach->name << " and detaching it.");
+    DataPartsVector parts_to_remove;
 
-    std::lock_guard<std::mutex> lock(data_parts_mutex);
+    if (drop_range.min_block > drop_range.max_block)
+        return parts_to_remove;
+
+    auto partition_range = getDataPartsPartitionRange(drop_range.partition_id);
+
+    for (const DataPartPtr & part : partition_range)
+    {
+        if (part->info.partition_id != drop_range.partition_id)
+            throw Exception("Unexpected partition_id of part " + part->name + ". This is a bug.", ErrorCodes::LOGICAL_ERROR);
+
+        if (part->info.min_block < drop_range.min_block)
+        {
+            if (drop_range.min_block <= part->info.max_block)
+            {
+                /// Intersect left border
+                String error = "Unexpected merged part " + part->name + " intersecting drop range " + drop_range.getPartName();
+                if (!skip_intersecting_parts)
+                    throw Exception(error, ErrorCodes::LOGICAL_ERROR);
+
+                LOG_WARNING(log, error);
+            }
+
+            continue;
+        }
+
+        /// Stop on new parts
+        if (part->info.min_block > drop_range.max_block)
+            break;
+
+        if (part->info.min_block <= drop_range.max_block && drop_range.max_block < part->info.max_block)
+        {
+            /// Intersect right border
+            String error = "Unexpected merged part " + part->name + " intersecting drop range " + drop_range.getPartName();
+            if (!skip_intersecting_parts)
+                throw Exception(error, ErrorCodes::LOGICAL_ERROR);
+
+            LOG_WARNING(log, error);
+            continue;
+        }
+
+        if (part->state != DataPartState::Deleting)
+            parts_to_remove.emplace_back(part);
+    }
+
+    removePartsFromWorkingSet(parts_to_remove, clear_without_timeout, lock);
+
+    return parts_to_remove;
+}
+
+void MergeTreeData::forgetPartAndMoveToDetached(const MergeTreeData::DataPartPtr & part_to_detach, const String & prefix, bool
+restore_covered)
+{
+    LOG_INFO(log, "Renaming " << part_to_detach->relative_path << " to " << prefix << part_to_detach->name << " and forgiving it.");
+
+    auto data_parts_lock = lockParts();
 
     auto it_part = data_parts_by_info.find(part_to_detach->info);
     if (it_part == data_parts_by_info.end())
         throw Exception("No such data part " + part_to_detach->getNameWithState(), ErrorCodes::NO_SUCH_DATA_PART);
 
-    /// What if part_to_detach is reference to *it_part? Make a new owner just in case.
+    /// What if part_to_detach is a reference to *it_part? Make a new owner just in case.
     DataPartPtr part = *it_part;
 
     if (part->state == DataPartState::Committed)
         removePartContributionToColumnSizes(part);
     modifyPartState(it_part, DataPartState::Deleting);
-    if (move_to_detached || !prefix.empty())
-        part->renameAddPrefix(move_to_detached, prefix);
+
+    part->renameToDetached(prefix);
+
     data_parts_indexes.erase(it_part);
 
     if (restore_covered && part->info.level == 0)
@@ -1708,7 +1787,7 @@ size_t MergeTreeData::getMaxPartsCountForPartition() const
 }
 
 
-void MergeTreeData::delayInsertIfNeeded(Poco::Event * until)
+void MergeTreeData::delayInsertOrThrowIfNeeded(Poco::Event *until) const
 {
     const size_t parts_count = getMaxPartsCountForPartition();
     if (parts_count < settings.parts_to_delay_insert)
@@ -1738,20 +1817,28 @@ void MergeTreeData::delayInsertIfNeeded(Poco::Event * until)
         std::this_thread::sleep_for(std::chrono::milliseconds(static_cast<size_t>(delay_milliseconds)));
 }
 
-MergeTreeData::DataPartPtr MergeTreeData::getActiveContainingPart(const String & part_name)
+void MergeTreeData::throwInsertIfNeeded() const
 {
-    auto part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
+    const size_t parts_count = getMaxPartsCountForPartition();
 
-    std::lock_guard<std::mutex> lock(data_parts_mutex);
+    if (parts_count >= settings.parts_to_throw_insert)
+    {
+        ProfileEvents::increment(ProfileEvents::RejectedInserts);
+        throw Exception("Too many parts (" + toString(parts_count) + "). Merges are processing significantly slower than inserts.", ErrorCodes::TOO_MANY_PARTS);
+    }
+}
 
-    auto committed_parts_range = getDataPartsStateRange(DataPartState::Committed);
+MergeTreeData::DataPartPtr MergeTreeData::getActiveContainingPart(
+    const MergeTreePartInfo & part_info, MergeTreeData::DataPartState state, DataPartsLock & /*lock*/)
+{
+    auto committed_parts_range = getDataPartsStateRange(state);
 
     /// The part can be covered only by the previous or the next one in data_parts.
-    auto it = data_parts_by_state_and_info.lower_bound(DataPartStateAndInfo(DataPartState::Committed, part_info));
+    auto it = data_parts_by_state_and_info.lower_bound(DataPartStateAndInfo{state, part_info});
 
     if (it != committed_parts_range.end())
     {
-        if ((*it)->name == part_name)
+        if ((*it)->info == part_info)
             return *it;
         if ((*it)->info.contains(part_info))
             return *it;
@@ -1767,11 +1854,28 @@ MergeTreeData::DataPartPtr MergeTreeData::getActiveContainingPart(const String &
     return nullptr;
 }
 
-
-MergeTreeData::DataPartPtr MergeTreeData::getPartIfExists(const String & part_name, const MergeTreeData::DataPartStates & valid_states)
+MergeTreeData::DataPartPtr MergeTreeData::getActiveContainingPart(const String & part_name)
 {
     auto part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
 
+    DataPartsLock data_parts_lock(data_parts_mutex);
+    return getActiveContainingPart(part_info, DataPartState::Committed, data_parts_lock);
+}
+
+
+MergeTreeData::DataPartsVector MergeTreeData::getDataPartsVectorInPartition(MergeTreeData::DataPartState state, const String & partition_id)
+{
+    DataPartStateAndPartitionID state_with_partition{state, partition_id};
+
+    std::lock_guard<std::mutex> lock(data_parts_mutex);
+    return DataPartsVector(
+        data_parts_by_state_and_info.lower_bound(state_with_partition),
+        data_parts_by_state_and_info.upper_bound(state_with_partition));
+}
+
+
+MergeTreeData::DataPartPtr MergeTreeData::getPartIfExists(const MergeTreePartInfo & part_info, const MergeTreeData::DataPartStates & valid_states)
+{
     std::lock_guard<std::mutex> lock(data_parts_mutex);
 
     auto it = data_parts_by_info.find(part_info);
@@ -1787,6 +1891,11 @@ MergeTreeData::DataPartPtr MergeTreeData::getPartIfExists(const String & part_na
     return nullptr;
 }
 
+MergeTreeData::DataPartPtr MergeTreeData::getPartIfExists(const String & part_name, const MergeTreeData::DataPartStates & valid_states)
+{
+    return getPartIfExists(MergeTreePartInfo::fromPartName(part_name, format_version), valid_states);
+}
+
 
 MergeTreeData::MutableDataPartPtr MergeTreeData::loadPartAndFixMetadata(const String & relative_path)
 {
@@ -2012,7 +2121,7 @@ String MergeTreeData::getPartitionIDFromQuery(const ASTPtr & ast, const Context
     String partition_id = partition.getID(*this);
 
     {
-        std::lock_guard<std::mutex> data_parts_lock(data_parts_mutex);
+        DataPartsLock data_parts_lock(data_parts_mutex);
         DataPartPtr existing_part_in_partition = getAnyPartInPartition(partition_id, data_parts_lock);
         if (existing_part_in_partition && existing_part_in_partition->partition.value != partition.value)
         {
@@ -2098,12 +2207,9 @@ MergeTreeData::DataPartsVector MergeTreeData::getDataPartsVector() const
 }
 
 MergeTreeData::DataPartPtr MergeTreeData::getAnyPartInPartition(
-    const String & partition_id, std::lock_guard<std::mutex> & /*data_parts_lock*/)
+    const String & partition_id, DataPartsLock & /*data_parts_lock*/)
 {
-    auto min_block = std::numeric_limits<Int64>::min();
-    MergeTreePartInfo dummy_part_info(partition_id, min_block, min_block, 0);
-
-    auto it = data_parts_by_state_and_info.lower_bound(DataPartStateAndInfo(DataPartState::Committed, dummy_part_info));
+    auto it = data_parts_by_state_and_info.lower_bound(DataPartStateAndPartitionID{DataPartState::Committed, partition_id});
 
     if (it != data_parts_by_state_and_info.end() && (*it)->state == DataPartState::Committed && (*it)->info.partition_id == partition_id)
         return *it;
@@ -2130,19 +2236,20 @@ void MergeTreeData::Transaction::rollback()
     clear();
 }
 
-MergeTreeData::DataPartsVector MergeTreeData::Transaction::commit()
+MergeTreeData::DataPartsVector MergeTreeData::Transaction::commit(MergeTreeData::DataPartsLock * acquired_parts_lock)
 {
     DataPartsVector total_covered_parts;
 
     if (!isEmpty())
     {
-        std::lock_guard<std::mutex> data_parts_lock(data->data_parts_mutex);
+        auto parts_lock = acquired_parts_lock ? MergeTreeData::DataPartsLock() : data->lockParts();
+        auto owing_parts_lock = acquired_parts_lock ? acquired_parts_lock : &parts_lock;
 
         auto current_time = time(nullptr);
         for (const DataPartPtr & part : precommitted_parts)
         {
             DataPartPtr covering_part;
-            DataPartsVector covered_parts = data->getActivePartsToReplace(part->info, part->name, covering_part, data_parts_lock);
+            DataPartsVector covered_parts = data->getActivePartsToReplace(part->info, part->name, covering_part, *owing_parts_lock);
             if (covering_part)
             {
                 LOG_WARNING(data->log, "Tried to commit obsolete part " << part->name
@@ -2212,4 +2319,67 @@ bool MergeTreeData::mayBenefitFromIndexForIn(const ASTPtr & left_in_operand) con
     }
 }
 
+MergeTreeData * MergeTreeData::checkStructureAndGetMergeTreeData(const StoragePtr & source_table) const
+{
+    MergeTreeData * src_data;
+    if (auto storage_merge_tree = dynamic_cast<StorageMergeTree *>(source_table.get()))
+        src_data = &storage_merge_tree->data;
+    else if (auto storage_replicated_merge_tree = dynamic_cast<StorageReplicatedMergeTree *>(source_table.get()))
+        src_data = &storage_replicated_merge_tree->data;
+    else
+    {
+        throw Exception("Table " + table_name + " supports attachPartitionFrom only for MergeTree or ReplicatedMergeTree engines."
+                        " Got " + source_table->getName(), ErrorCodes::NOT_IMPLEMENTED);
+    }
+
+    if (getColumns().getAllPhysical().sizeOfDifference(src_data->getColumns().getAllPhysical()))
+        throw Exception("Tables have different structure", ErrorCodes::INCOMPATIBLE_COLUMNS);
+
+    auto query_to_string = [] (const ASTPtr & ast)
+    {
+        return ast ? queryToString(ast) : "";
+    };
+
+    if (query_to_string(secondary_sort_expr_ast) != query_to_string(secondary_sort_expr_ast))
+        throw Exception("Tables have different ordering", ErrorCodes::BAD_ARGUMENTS);
+
+    if (query_to_string(partition_expr_ast) != query_to_string(src_data->partition_expr_ast))
+        throw Exception("Tables have different partition key", ErrorCodes::BAD_ARGUMENTS);
+
+    if (format_version != src_data->format_version)
+        throw Exception("Tables have different format_version", ErrorCodes::BAD_ARGUMENTS);
+
+    return src_data;
+}
+
+MergeTreeData::MutableDataPartPtr MergeTreeData::cloneAndLoadDataPart(const MergeTreeData::DataPartPtr & src_part,
+                                                                      const String & tmp_part_prefix,
+                                                                      const MergeTreePartInfo & dst_part_info)
+{
+    String dst_part_name;
+    if (format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
+            dst_part_name = dst_part_info.getPartNameV0(src_part->getMinDate(), src_part->getMaxDate());
+        else
+            dst_part_name = dst_part_info.getPartName();
+
+    String tmp_dst_part_name = tmp_part_prefix + dst_part_name;
+
+    Poco::Path dst_part_absolute_path = Poco::Path(full_path + tmp_dst_part_name).absolute();
+    Poco::Path src_part_absolute_path = Poco::Path(src_part->getFullPath()).absolute();
+
+    if (Poco::File(dst_part_absolute_path).exists())
+        throw Exception("Part in " + dst_part_absolute_path.toString() + " already exists", ErrorCodes::DIRECTORY_ALREADY_EXISTS);
+
+    LOG_DEBUG(log, "Cloning part " << src_part_absolute_path.toString() << " to " << dst_part_absolute_path.toString());
+    localBackup(src_part_absolute_path, dst_part_absolute_path);
+
+    MergeTreeData::MutableDataPartPtr dst_data_part = std::make_shared<MergeTreeData::DataPart>(*this, dst_part_name, dst_part_info);
+    dst_data_part->relative_path = tmp_dst_part_name;
+    dst_data_part->is_temp = true;
+
+    dst_data_part->loadColumnsChecksumsIndexes(require_part_metadata, true);
+    dst_data_part->modification_time = Poco::File(dst_part_absolute_path).getLastModified().epochTime();
+    return dst_data_part;
+}
+
 }

dbms/src/Storages/MergeTree/MergeTreeData.h

@@ -20,6 +20,8 @@
 #include <boost/multi_index/ordered_index.hpp>
 #include <boost/multi_index/global_fun.hpp>
 #include <boost/range/iterator_range_core.hpp>
+#include "../../Core/Types.h"
+
 
 namespace DB
 {
@@ -94,6 +96,7 @@ public:
     using DataPart = MergeTreeDataPart;
 
     using MutableDataPartPtr = std::shared_ptr<DataPart>;
+    using MutableDataPartsVector = std::vector<MutableDataPartPtr>;
     /// After the DataPart is added to the working set, it cannot be changed.
     using DataPartPtr = std::shared_ptr<const DataPart>;
 
@@ -106,10 +109,17 @@ public:
     {
         DataPartState state;
         const MergeTreePartInfo & info;
-
-        DataPartStateAndInfo(DataPartState state, const MergeTreePartInfo & info) : state(state), info(info) {}
     };
 
+    /// Auxiliary structure for index comparison
+    struct DataPartStateAndPartitionID
+    {
+        DataPartState state;
+        String partition_id;
+    };
+
+    STRONG_TYPEDEF(String, PartitionID);
+
     struct LessDataPart
     {
         using is_transparent = void;
@@ -117,6 +127,8 @@ public:
         bool operator()(const DataPartPtr & lhs, const MergeTreePartInfo & rhs) const { return lhs->info < rhs; }
         bool operator()(const MergeTreePartInfo & lhs, const DataPartPtr & rhs) const { return lhs < rhs->info; }
         bool operator()(const DataPartPtr & lhs, const DataPartPtr & rhs) const { return lhs->info < rhs->info; }
+        bool operator()(const MergeTreePartInfo & lhs, const PartitionID & rhs) const { return lhs.partition_id < rhs.toUnderType(); }
+        bool operator()(const PartitionID & lhs, const MergeTreePartInfo & rhs) const { return lhs.toUnderType() < rhs.partition_id; }
     };
 
     struct LessStateDataPart
@@ -138,11 +150,26 @@ public:
         {
             return static_cast<size_t>(state) < static_cast<size_t>(info.state);
         }
+
+        bool operator() (const DataPartStateAndInfo & lhs, const DataPartStateAndPartitionID & rhs) const
+        {
+            return std::forward_as_tuple(static_cast<UInt8>(lhs.state), lhs.info.partition_id)
+                   < std::forward_as_tuple(static_cast<UInt8>(rhs.state), rhs.partition_id);
+        }
+
+        bool operator() (const DataPartStateAndPartitionID & lhs, const DataPartStateAndInfo & rhs) const
+        {
+            return std::forward_as_tuple(static_cast<UInt8>(lhs.state), lhs.partition_id)
+                   < std::forward_as_tuple(static_cast<UInt8>(rhs.state), rhs.info.partition_id);
+        }
     };
 
     using DataParts = std::set<DataPartPtr, LessDataPart>;
     using DataPartsVector = std::vector<DataPartPtr>;
 
+    using DataPartsLock = std::unique_lock<std::mutex>;
+    DataPartsLock lockParts() const { return DataPartsLock(data_parts_mutex); }
+
     /// Auxiliary object to add a set of parts into the working set in two steps:
     /// * First, as PreCommitted parts (the parts are ready, but not yet in the active set).
     /// * Next, if commit() is called, the parts are added to the active set and the parts that are
@@ -153,8 +180,7 @@ public:
     public:
         Transaction() {}
 
-        /// Return parts marked Obsolete as a result of the transaction commit.
-        DataPartsVector commit();
+        DataPartsVector commit(MergeTreeData::DataPartsLock * acquired_parts_lock = nullptr);
 
         void rollback();
 
@@ -215,7 +241,7 @@ public:
         }
 
         DataPartPtr data_part;
-        std::unique_lock<std::mutex> alter_lock;
+        DataPartsLock alter_lock;
 
         DataPart::Checksums new_checksums;
         NamesAndTypesList new_columns;
@@ -347,9 +373,14 @@ public:
 
     /// Returns a committed part with the given name or a part containing it. If there is no such part, returns nullptr.
     DataPartPtr getActiveContainingPart(const String & part_name);
+    DataPartPtr getActiveContainingPart(const MergeTreePartInfo & part_info, DataPartState state, DataPartsLock &lock);
+
+    /// Returns all parts in specified partition
+    DataPartsVector getDataPartsVectorInPartition(DataPartState state, const String & partition_id);
 
     /// Returns the part with the given name and state or nullptr if no such part.
     DataPartPtr getPartIfExists(const String & part_name, const DataPartStates & valid_states);
+    DataPartPtr getPartIfExists(const MergeTreePartInfo & part_info, const DataPartStates & valid_states);
 
     /// Total size of active parts in bytes.
     size_t getTotalActiveSizeInBytes() const;
@@ -358,7 +389,8 @@ public:
 
     /// If the table contains too many active parts, sleep for a while to give them time to merge.
     /// If until is non-null, wake up from the sleep earlier if the event happened.
-    void delayInsertIfNeeded(Poco::Event * until = nullptr);
+    void delayInsertOrThrowIfNeeded(Poco::Event *until = nullptr) const;
+    void throwInsertIfNeeded() const;
 
     /// Renames temporary part to a permanent part and adds it to the parts set.
     /// It is assumed that the part does not intersect with existing parts.
@@ -374,16 +406,32 @@ public:
     DataPartsVector renameTempPartAndReplace(
         MutableDataPartPtr & part, SimpleIncrement * increment = nullptr, Transaction * out_transaction = nullptr);
 
+    /// Low-level version of previous one, doesn't lock mutex
+    void renameTempPartAndReplace(
+            MutableDataPartPtr & part, SimpleIncrement * increment, Transaction * out_transaction, DataPartsLock & lock,
+            DataPartsVector * out_covered_parts = nullptr);
+
     /// Removes parts from the working set parts.
     /// Parts in add must already be in data_parts with PreCommitted, Committed, or Outdated states.
     /// If clear_without_timeout is true, the parts will be deleted at once, or during the next call to
     /// clearOldParts (ignoring old_parts_lifetime).
-    void removePartsFromWorkingSet(const DataPartsVector & remove, bool clear_without_timeout);
+    void removePartsFromWorkingSet(const DataPartsVector & remove, bool clear_without_timeout, DataPartsLock * acquired_lock = nullptr);
+    void removePartsFromWorkingSet(const DataPartsVector & remove, bool clear_without_timeout, DataPartsLock & acquired_lock);
 
-    /// Renames the part to detached/<prefix>_<part> and forgets about it. The data won't be deleted in
-    /// clearOldParts.
+    /// Removes all parts from the working set parts
+    ///  for which (partition_id = drop_range.partition_id && min_block >= drop_range.min_block && max_block <= drop_range.max_block).
+    /// If a part intersecting drop_range.max_block is found, an exception will be thrown.
+    /// Used in REPLACE PARTITION command;
+    DataPartsVector removePartsInRangeFromWorkingSet(const MergeTreePartInfo & drop_range, bool clear_without_timeout,
+                                                     bool skip_intersecting_parts, DataPartsLock & lock);
+
+    /// Renames the part to detached/<prefix>_<part> and removes it from working set.
+    void removePartsFromWorkingSetAndCloneToDetached(const DataPartsVector & parts, bool clear_without_timeout, const String & prefix = "");
+
+    /// Renames the part to detached/<prefix>_<part> and removes it from data_parts,
+    //// so it will not be deleted in clearOldParts.
     /// If restore_covered is true, adds to the working set inactive parts, which were merged into the deleted part.
-    void renameAndDetachPart(const DataPartPtr & part, const String & prefix = "", bool restore_covered = false, bool move_to_detached = true);
+    void forgetPartAndMoveToDetached(const DataPartPtr & part, const String & prefix = "", bool restore_covered = false);
 
     /// Returns old inactive parts that can be deleted. At the same time removes them from the list of parts
     /// but not from the disk.
@@ -477,6 +525,13 @@ public:
     /// For ATTACH/DETACH/DROP PARTITION.
     String getPartitionIDFromQuery(const ASTPtr & partition, const Context & context);
 
+    /// Extracts MergeTreeData of other *MergeTree* storage
+    ///  and checks that their structure suitable for ALTER TABLE ATTACH PARTITION FROM
+    /// Tables structure should be locked.
+    MergeTreeData * checkStructureAndGetMergeTreeData(const StoragePtr & source_table) const;
+
+    MergeTreeData::MutableDataPartPtr cloneAndLoadDataPart(const MergeTreeData::DataPartPtr & src_part, const String & tmp_part_prefix,
+                                                           const MergeTreePartInfo & dst_part_info);
 
     MergeTreeDataFormatVersion format_version;
 
@@ -515,6 +570,8 @@ private:
     friend class StorageMergeTree;
     friend class ReplicatedMergeTreeAlterThread;
     friend class MergeTreeDataMerger;
+    friend class StorageMergeTree;
+    friend class StorageReplicatedMergeTree;
 
     bool require_part_metadata;
 
@@ -587,6 +644,13 @@ private:
         return {begin, end};
     }
 
+    boost::iterator_range<DataPartIteratorByInfo> getDataPartsPartitionRange(const String & partition_id) const
+    {
+        auto begin = data_parts_by_info.lower_bound(PartitionID(partition_id), LessDataPart());
+        auto end = data_parts_by_info.upper_bound(PartitionID(partition_id), LessDataPart());
+        return {begin, end};
+    }
+
     static decltype(auto) getStateModifier(DataPartState state)
     {
         return [state] (const DataPartPtr & part) { part->state = state; };
@@ -641,7 +705,7 @@ private:
     void removePartContributionToColumnSizes(const DataPartPtr & part);
 
     /// If there is no part in the partition with ID `partition_id`, returns empty ptr. Should be called under the lock.
-    DataPartPtr getAnyPartInPartition(const String & partition_id, std::lock_guard<std::mutex> & data_parts_lock);
+    DataPartPtr getAnyPartInPartition(const String & partition_id, DataPartsLock & data_parts_lock);
 
     /// Return parts in the Committed set that are covered by the new_part_info or the part that covers it.
     /// Will check that the new part doesn't already exist and that it doesn't intersect existing part.
@@ -649,7 +713,7 @@ private:
         const MergeTreePartInfo & new_part_info,
         const String & new_part_name,
         DataPartPtr & out_covering_part,
-        std::lock_guard<std::mutex> & data_parts_lock) const;
+        DataPartsLock & data_parts_lock) const;
 
     /// Checks whether the column is in the primary key, possibly wrapped in a chain of functions with single argument.
     bool isPrimaryOrMinMaxKeyColumnPossiblyWrappedInFunctions(const ASTPtr & node) const;

dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp

@@ -93,8 +93,8 @@ void MergeTreeDataMerger::FuturePart::assign(MergeTreeData::DataPartsVector part
 
     if (parts.front()->storage.format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
     {
-        DayNum_t min_date = DayNum_t(std::numeric_limits<UInt16>::max());
-        DayNum_t max_date = DayNum_t(std::numeric_limits<UInt16>::min());
+        DayNum min_date = DayNum(std::numeric_limits<UInt16>::max());
+        DayNum max_date = DayNum(std::numeric_limits<UInt16>::min());
         for (const auto & part : parts)
         {
             min_date = std::min(min_date, part->getMinDate());

dbms/src/Storages/MergeTree/MergeTreeDataPart.cpp

@@ -13,6 +13,7 @@
 #include <Common/SipHash.h>
 #include <Common/escapeForFileName.h>
 #include <Common/StringUtils/StringUtils.h>
+#include <Common/localBackup.h>
 #include <Storages/MergeTree/MergeTreeDataPart.h>
 #include <Storages/MergeTree/MergeTreeData.h>
 
@@ -230,21 +231,21 @@ String MergeTreeDataPart::getNameWithPrefix() const
 }
 
 
-DayNum_t MergeTreeDataPart::getMinDate() const
+DayNum MergeTreeDataPart::getMinDate() const
 {
     if (storage.minmax_idx_date_column_pos != -1)
-        return DayNum_t(minmax_idx.min_values[storage.minmax_idx_date_column_pos].get<UInt64>());
+        return DayNum(minmax_idx.min_values[storage.minmax_idx_date_column_pos].get<UInt64>());
     else
-        return DayNum_t();
+        return DayNum();
 }
 
 
-DayNum_t MergeTreeDataPart::getMaxDate() const
+DayNum MergeTreeDataPart::getMaxDate() const
 {
     if (storage.minmax_idx_date_column_pos != -1)
-        return DayNum_t(minmax_idx.max_values[storage.minmax_idx_date_column_pos].get<UInt64>());
+        return DayNum(minmax_idx.max_values[storage.minmax_idx_date_column_pos].get<UInt64>());
     else
-        return DayNum_t();
+        return DayNum();
 }
 
 
@@ -366,29 +367,45 @@ void MergeTreeDataPart::renameTo(const String & new_relative_path, bool remove_n
 }
 
 
-void MergeTreeDataPart::renameAddPrefix(bool to_detached, const String & prefix) const
+String MergeTreeDataPart::getRelativePathForDetachedPart(const String & prefix) const
 {
+    String res;
     unsigned try_no = 0;
-    auto dst_name = [&, this] { return (to_detached ? "detached/" : "") + prefix + name + (try_no ? "_try" + DB::toString(try_no) : ""); };
+    auto dst_name = [&, this] { return "detached/" + prefix + name + (try_no ? "_try" + DB::toString(try_no) : ""); };
 
-    if (to_detached)
+    /** If you need to detach a part, and directory into which we want to rename it already exists,
+        *  we will rename to the directory with the name to which the suffix is added in the form of "_tryN".
+        * This is done only in the case of `to_detached`, because it is assumed that in this case the exact name does not matter.
+        * No more than 10 attempts are made so that there are not too many junk directories left.
+        */
+    while (try_no < 10)
     {
-        /** If you need to detach a part, and directory into which we want to rename it already exists,
-            *  we will rename to the directory with the name to which the suffix is added in the form of "_tryN".
-            * This is done only in the case of `to_detached`, because it is assumed that in this case the exact name does not matter.
-            * No more than 10 attempts are made so that there are not too many junk directories left.
-            */
-        while (try_no < 10 && Poco::File(storage.full_path + dst_name()).exists())
-        {
-            LOG_WARNING(storage.log, "Directory " << dst_name() << " (to detach to) is already exist."
-                " Will detach to directory with '_tryN' suffix.");
-            ++try_no;
-        }
+        res = dst_name();
+
+        if (!Poco::File(storage.full_path + res).exists())
+            return res;
+
+        LOG_WARNING(storage.log, "Directory " << dst_name() << " (to detach to) is already exist."
+            " Will detach to directory with '_tryN' suffix.");
+        ++try_no;
     }
 
-    renameTo(dst_name());
+    return res;
 }
 
+void MergeTreeDataPart::renameToDetached(const String & prefix) const
+{
+    renameTo(getRelativePathForDetachedPart(prefix));
+}
+
+
+void MergeTreeDataPart::makeCloneInDetached(const String & prefix) const
+{
+    Poco::Path src(getFullPath());
+    Poco::Path dst(storage.full_path + getRelativePathForDetachedPart(prefix));
+    /// Backup is not recursive (max_level is 0), so do not copy inner directories
+    localBackup(src, dst, 0);
+}
 
 void MergeTreeDataPart::loadColumnsChecksumsIndexes(bool require_columns_checksums, bool check_consistency)
 {
@@ -452,8 +469,8 @@ void MergeTreeDataPart::loadPartitionAndMinMaxIndex()
 {
     if (storage.format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
     {
-        DayNum_t min_date;
-        DayNum_t max_date;
+        DayNum min_date;
+        DayNum max_date;
         MergeTreePartInfo::parseMinMaxDatesFromPartName(name, min_date, max_date);
 
         const auto & date_lut = DateLUT::instance();

dbms/src/Storages/MergeTree/MergeTreeDataPart.h

@@ -8,6 +8,8 @@
 #include <Storages/MergeTree/MergeTreeDataPartChecksum.h>
 #include <Columns/IColumn.h>
 #include <shared_mutex>
+#include "../../../../contrib/poco/Foundation/include/Poco/Path.h"
+#include "../../Core/Types.h"
 
 
 namespace DB
@@ -63,8 +65,8 @@ struct MergeTreeDataPart
     bool contains(const MergeTreeDataPart & other) const { return info.contains(other.info); }
 
     /// If the partition key includes date column (a common case), these functions will return min and max values for this column.
-    DayNum_t getMinDate() const;
-    DayNum_t getMaxDate() const;
+    DayNum getMinDate() const;
+    DayNum getMaxDate() const;
 
     MergeTreeData & storage;
 
@@ -176,7 +178,7 @@ struct MergeTreeDataPart
         MinMaxIndex() = default;
 
         /// For month-based partitioning.
-        MinMaxIndex(DayNum_t min_date, DayNum_t max_date)
+        MinMaxIndex(DayNum min_date, DayNum max_date)
             : min_values(1, static_cast<UInt64>(min_date))
             , max_values(1, static_cast<UInt64>(max_date))
             , initialized(true)
@@ -225,8 +227,14 @@ struct MergeTreeDataPart
     /// Changes only relative_dir_name, you need to update other metadata (name, is_temp) explicitly
     void renameTo(const String & new_relative_path, bool remove_new_dir_if_exists = true) const;
 
-    /// Renames a part by appending a prefix to the name. To_detached - also moved to the detached directory.
-    void renameAddPrefix(bool to_detached, const String & prefix) const;
+    /// Generate unique path to detach part
+    String getRelativePathForDetachedPart(const String & prefix) const;
+
+    /// Moves a part to detached/ directory and adds prefix to its name
+    void renameToDetached(const String & prefix) const;
+
+    /// Makes clone of a part in detached/ directory via hard links
+    void makeCloneInDetached(const String & prefix) const;
 
     /// Populates columns_to_size map (compressed size).
     void accumulateColumnSizes(ColumnToSize & column_to_size) const;

dbms/src/Storages/MergeTree/MergeTreeDataPartChecksum.cpp

@@ -1,5 +1,6 @@
 #include "MergeTreeDataPartChecksum.h"
 #include <Common/SipHash.h>
+#include <Common/hex.h>
 #include <IO/ReadHelpers.h>
 #include <IO/WriteHelpers.h>
 #include <IO/ReadBufferFromString.h>
@@ -272,6 +273,34 @@ bool MergeTreeDataPartChecksums::isBadChecksumsErrorCode(int code)
            || code == ErrorCodes::UNEXPECTED_FILE_IN_DATA_PART;
 }
 
+/// Puts into hash "stream" length of the string and its bytes
+static void updateHash(SipHash & hash, const std::string & data)
+{
+    UInt64 len = data.size();
+    hash.update(len);
+    hash.update(data.data(), len);
+}
+
+/// Hash is the same as MinimalisticDataPartChecksums::hash_of_all_files
+String MergeTreeDataPartChecksums::getTotalChecksumHex() const
+{
+    SipHash hash_of_all_files;
+
+    for (const auto & elem : files)
+    {
+        const String & name = elem.first;
+        const auto & checksum = elem.second;
+
+        updateHash(hash_of_all_files, name);
+        hash_of_all_files.update(checksum.file_hash);
+    }
+
+    UInt64 lo, hi;
+    hash_of_all_files.get128(lo, hi);
+
+    return getHexUIntUppercase(hi) + getHexUIntUppercase(lo);
+}
+
 void MinimalisticDataPartChecksums::serialize(WriteBuffer & to) const
 {
     writeString("checksums format version: 5\n", to);
@@ -331,31 +360,24 @@ void MinimalisticDataPartChecksums::computeTotalChecksums(const MergeTreeDataPar
     SipHash hash_of_uncompressed_files_;
     SipHash uncompressed_hash_of_compressed_files_;
 
-    auto update_hash = [] (SipHash & hash, const std::string & data)
-    {
-        UInt64 len = data.size();
-        hash.update(len);
-        hash.update(data.data(), len);
-    };
-
     for (const auto & elem : full_checksums.files)
     {
         const String & name = elem.first;
         const auto & checksum = elem.second;
 
-        update_hash(hash_of_all_files_, name);
+        updateHash(hash_of_all_files_, name);
         hash_of_all_files_.update(checksum.file_hash);
 
         if (!checksum.is_compressed)
         {
             ++num_uncompressed_files;
-            update_hash(hash_of_uncompressed_files_, name);
+            updateHash(hash_of_uncompressed_files_, name);
             hash_of_uncompressed_files_.update(checksum.file_hash);
         }
         else
         {
             ++num_compressed_files;
-            update_hash(uncompressed_hash_of_compressed_files_, name);
+            updateHash(uncompressed_hash_of_compressed_files_, name);
             uncompressed_hash_of_compressed_files_.update(checksum.uncompressed_hash);
         }
     }

dbms/src/Storages/MergeTree/MergeTreeDataPartChecksum.h

@@ -79,6 +79,9 @@ struct MergeTreeDataPartChecksums
     /// Checksum from the set of checksums of .bin files (for deduplication).
     void computeTotalChecksumDataOnly(SipHash & hash) const;
 
+    /// SipHash of all all files hashes represented as hex string
+    String getTotalChecksumHex() const;
+
     String getSerializedString() const;
     static MergeTreeDataPartChecksums deserializeFrom(const String & s);
 };

dbms/src/Storages/MergeTree/MergeTreeDataWriter.cpp

@@ -140,13 +140,13 @@ MergeTreeData::MutableDataPartPtr MergeTreeDataWriter::writeTempPart(BlockWithPa
     String part_name;
     if (data.format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
     {
-        DayNum_t min_date(minmax_idx.min_values[data.minmax_idx_date_column_pos].get<UInt64>());
-        DayNum_t max_date(minmax_idx.max_values[data.minmax_idx_date_column_pos].get<UInt64>());
+        DayNum min_date(minmax_idx.min_values[data.minmax_idx_date_column_pos].get<UInt64>());
+        DayNum max_date(minmax_idx.max_values[data.minmax_idx_date_column_pos].get<UInt64>());
 
         const auto & date_lut = DateLUT::instance();
 
-        DayNum_t min_month = date_lut.toFirstDayNumOfMonth(DayNum_t(min_date));
-        DayNum_t max_month = date_lut.toFirstDayNumOfMonth(DayNum_t(max_date));
+        DayNum min_month = date_lut.toFirstDayNumOfMonth(DayNum(min_date));
+        DayNum max_month = date_lut.toFirstDayNumOfMonth(DayNum(max_date));
 
         if (min_month != max_month)
             throw Exception("Logical error: part spans more than one month.");

dbms/src/Storages/MergeTree/MergeTreePartInfo.cpp

@@ -78,7 +78,7 @@ bool MergeTreePartInfo::tryParsePartName(const String & dir_name, MergeTreePartI
 }
 
 
-void MergeTreePartInfo::parseMinMaxDatesFromPartName(const String & dir_name, DayNum_t & min_date, DayNum_t & max_date)
+void MergeTreePartInfo::parseMinMaxDatesFromPartName(const String & dir_name, DayNum & min_date, DayNum & max_date)
 {
     UInt32 min_yyyymmdd = 0;
     UInt32 max_yyyymmdd = 0;
@@ -97,8 +97,8 @@ void MergeTreePartInfo::parseMinMaxDatesFromPartName(const String & dir_name, Da
     min_date = date_lut.YYYYMMDDToDayNum(min_yyyymmdd);
     max_date = date_lut.YYYYMMDDToDayNum(max_yyyymmdd);
 
-    DayNum_t min_month = date_lut.toFirstDayNumOfMonth(min_date);
-    DayNum_t max_month = date_lut.toFirstDayNumOfMonth(max_date);
+    DayNum min_month = date_lut.toFirstDayNumOfMonth(min_date);
+    DayNum max_month = date_lut.toFirstDayNumOfMonth(max_date);
 
     if (min_month != max_month)
         throw Exception("Part name " + dir_name + " contains different months", ErrorCodes::BAD_DATA_PART_NAME);
@@ -129,7 +129,7 @@ String MergeTreePartInfo::getPartName() const
 }
 
 
-String MergeTreePartInfo::getPartNameV0(DayNum_t left_date, DayNum_t right_date) const
+String MergeTreePartInfo::getPartNameV0(DayNum left_date, DayNum right_date) const
 {
     const auto & date_lut = DateLUT::instance();
 

dbms/src/Storages/MergeTree/MergeTreePartInfo.h

@@ -52,7 +52,7 @@ struct MergeTreePartInfo
     }
 
     String getPartName() const;
-    String getPartNameV0(DayNum_t left_date, DayNum_t right_date) const;
+    String getPartNameV0(DayNum left_date, DayNum right_date) const;
     UInt64 getBlocksCount() const
     {
         return static_cast<UInt64>(max_block - min_block + 1);
@@ -62,7 +62,7 @@ struct MergeTreePartInfo
 
     static bool tryParsePartName(const String & dir_name, MergeTreePartInfo * part_info, MergeTreeDataFormatVersion format_version);
 
-    static void parseMinMaxDatesFromPartName(const String & part_name, DayNum_t & min_date, DayNum_t & max_date);
+    static void parseMinMaxDatesFromPartName(const String & part_name, DayNum & min_date, DayNum & max_date);
 
     static bool contains(const String & outer_part_name, const String & inner_part_name, MergeTreeDataFormatVersion format_version);
 };

dbms/src/Storages/MergeTree/MergeTreePartition.cpp

@@ -52,7 +52,7 @@ String MergeTreePartition::getID(const MergeTreeData & storage) const
                 result += '-';
 
             if (typeid_cast<const DataTypeDate *>(storage.partition_key_sample.getByPosition(i).type.get()))
-                result += toString(DateLUT::instance().toNumYYYYMMDD(DayNum_t(value[i].safeGet<UInt64>())));
+                result += toString(DateLUT::instance().toNumYYYYMMDD(DayNum(value[i].safeGet<UInt64>())));
             else
                 result += applyVisitor(to_string_visitor, value[i]);
 

dbms/src/Storages/MergeTree/MergeTreeWhereOptimizer.cpp

@@ -334,7 +334,7 @@ bool MergeTreeWhereOptimizer::isPrimaryKeyAtom(const IAST * const ast) const
         if ((primary_key_columns.count(first_arg_name) && isConstant(args[1])) ||
             (primary_key_columns.count(second_arg_name) && isConstant(args[0])) ||
             (primary_key_columns.count(first_arg_name)
-                && (prepared_sets.count(args[1].get()) || typeid_cast<const ASTSubquery *>(args[1].get()))))
+                && (prepared_sets.count(args[1]->range) || typeid_cast<const ASTSubquery *>(args[1].get()))))
             return true;
     }
 

dbms/src/Storages/MergeTree/ReplicatedMergeTreeAlterThread.cpp

@@ -14,200 +14,198 @@ namespace DB
 static const auto ALTER_ERROR_SLEEP_MS = 10 * 1000;
 
 
-ReplicatedMergeTreeAlterThread::ReplicatedMergeTreeAlterThread(StorageReplicatedMergeTree & storage_)
-    : storage(storage_),
-    log(&Logger::get(storage.database_name + "." + storage.table_name + " (StorageReplicatedMergeTree, AlterThread)")),
-    thread([this] { run(); }) {}
+ReplicatedMergeTreeAlterThread::ReplicatedMergeTreeAlterThread(StorageReplicatedMergeTree & storage_) :
+    storage(storage_),
+    log(&Logger::get(storage.database_name + "." + storage.table_name + " (StorageReplicatedMergeTree, AlterThread)"))
+    {
+        task_handle = storage_.context.getSchedulePool().addTask("ReplicatedMergeTreeAlterThread", [this]{run();});
+        task_handle->schedule();
+    }
 
+ReplicatedMergeTreeAlterThread::~ReplicatedMergeTreeAlterThread()
+{
+    storage.context.getSchedulePool().removeTask(task_handle);
+}
 
 void ReplicatedMergeTreeAlterThread::run()
 {
-    setThreadName("ReplMTAlter");
-
     bool force_recheck_parts = true;
 
-    while (!need_stop)
+    try
     {
-        try
-        {
-            /** We have a description of columns in ZooKeeper, common for all replicas (Example: /clickhouse/tables/02-06/visits/columns),
-              *  as well as a description of columns in local file with metadata (storage.data.getColumnsList()).
-              *
-              * If these descriptions are different - you need to do ALTER.
-              *
-              * If stored version of the node (columns_version) differs from the version in ZK,
-              *  then the description of the columns in ZK does not necessarily differ from the local
-              *  - this can happen with a loop from ALTER-s, which as a whole, does not change anything.
-              * In this case, you need to update the stored version number,
-              *  and also check the structure of parts, and, if necessary, make ALTER.
-              *
-              * Recorded version number needs to be updated after updating the metadata, under lock.
-              * This version number is checked against the current one for INSERT.
-              * That is, we make sure to insert blocks with the correct structure.
-              *
-              * When the server starts, previous ALTER might not have been completed.
-              * Therefore, for the first time, regardless of the changes, we check the structure of all parts,
-              *  (Example: /clickhouse/tables/02-06/visits/replicas/example02-06-1.yandex.ru/parts/20140806_20140831_131664_134988_3296/columns)
-              *  and do ALTER if necessary.
-              *
-              * TODO: Too complicated, rewrite everything.
-              */
+        /** We have a description of columns in ZooKeeper, common for all replicas (Example: /clickhouse/tables/02-06/visits/columns),
+          *  as well as a description of columns in local file with metadata (storage.data.getColumnsList()).
+          *
+          * If these descriptions are different - you need to do ALTER.
+          *
+          * If stored version of the node (columns_version) differs from the version in ZK,
+          *  then the description of the columns in ZK does not necessarily differ from the local
+          *  - this can happen with a loop from ALTER-s, which as a whole, does not change anything.
+          * In this case, you need to update the stored version number,
+          *  and also check the structure of parts, and, if necessary, make ALTER.
+          *
+          * Recorded version number needs to be updated after updating the metadata, under lock.
+          * This version number is checked against the current one for INSERT.
+          * That is, we make sure to insert blocks with the correct structure.
+          *
+          * When the server starts, previous ALTER might not have been completed.
+          * Therefore, for the first time, regardless of the changes, we check the structure of all parts,
+          *  (Example: /clickhouse/tables/02-06/visits/replicas/example02-06-1.yandex.ru/parts/20140806_20140831_131664_134988_3296/columns)
+          *  and do ALTER if necessary.
+          *
+          * TODO: Too complicated, rewrite everything.
+          */
 
-            auto zookeeper = storage.getZooKeeper();
+        auto zookeeper = storage.getZooKeeper();
 
-            zkutil::Stat stat;
-            const String columns_str = zookeeper->get(storage.zookeeper_path + "/columns", &stat, wakeup_event);
-            auto columns_in_zk = ColumnsDescription::parse(columns_str);
+        zkutil::Stat stat;
+        const String columns_str = zookeeper->getWatch(storage.zookeeper_path + "/columns", &stat, task_handle->getWatchCallback());
+        auto columns_in_zk = ColumnsDescription::parse(columns_str);
 
-            bool changed_version = (stat.version != storage.columns_version);
+        bool changed_version = (stat.version != storage.columns_version);
 
             {
                 /// If you need to lock table structure, then suspend merges.
-                ActionBlocker::LockHolder merge_blocker;
+                ActionLock merge_blocker;
 
-                if (changed_version || force_recheck_parts)
-                    merge_blocker = storage.merger.merges_blocker.cancel();
+            if (changed_version || force_recheck_parts)
+                merge_blocker = storage.merger.merges_blocker.cancel();
 
-                MergeTreeData::DataParts parts;
+            MergeTreeData::DataParts parts;
 
-                /// If columns description has changed, we will update table structure locally.
-                if (changed_version)
-                {
-                    /// Temporarily cancel part checks to avoid locking for long time.
-                    auto temporarily_stop_part_checks = storage.part_check_thread.temporarilyStop();
+            /// If columns description has changed, we will update table structure locally.
+            if (changed_version)
+            {
+                /// Temporarily cancel part checks to avoid locking for long time.
+                auto temporarily_stop_part_checks = storage.part_check_thread.temporarilyStop();
 
                     /// Temporarily cancel parts sending
-                    ActionBlocker::LockHolder data_parts_exchange_blocker;
+                    ActionLock data_parts_exchange_blocker;
                     if (storage.data_parts_exchange_endpoint_holder)
-                        data_parts_exchange_blocker = storage.data_parts_exchange_endpoint_holder->cancel();
+                        data_parts_exchange_blocker = storage.data_parts_exchange_endpoint_holder->getBlocker().cancel();
 
-                    /// Temporarily cancel part fetches
-                    auto fetches_blocker = storage.fetcher.blocker.cancel();
+                /// Temporarily cancel part fetches
+                auto fetches_blocker = storage.fetcher.blocker.cancel();
 
-                    LOG_INFO(log, "Changed version of 'columns' node in ZooKeeper. Waiting for structure write lock.");
+                LOG_INFO(log, "Changed version of 'columns' node in ZooKeeper. Waiting for structure write lock.");
 
-                    auto table_lock = storage.lockStructureForAlter(__PRETTY_FUNCTION__);
+                auto table_lock = storage.lockStructureForAlter(__PRETTY_FUNCTION__);
 
-                    if (columns_in_zk != storage.getColumns())
-                    {
-                        LOG_INFO(log, "Columns list changed in ZooKeeper. Applying changes locally.");
-
-                        storage.context.getDatabase(storage.database_name)->alterTable(
-                            storage.context, storage.table_name, columns_in_zk, {});
-                        storage.setColumns(std::move(columns_in_zk));
-
-                        /// Reinitialize primary key because primary key column types might have changed.
-                        storage.data.initPrimaryKey();
-
-                        LOG_INFO(log, "Applied changes to table.");
-                    }
-                    else
-                    {
-                        LOG_INFO(log, "Columns version changed in ZooKeeper, but data wasn't changed. It's like cyclic ALTERs.");
-                    }
-
-                    /// You need to get a list of parts under table lock to avoid race condition with merge.
-                    parts = storage.data.getDataParts();
-
-                    storage.columns_version = stat.version;
-                }
-
-                /// Update parts.
-                if (changed_version || force_recheck_parts)
+                if (columns_in_zk != storage.getColumns())
                 {
-                    auto table_lock = storage.lockStructure(false, __PRETTY_FUNCTION__);
+                    LOG_INFO(log, "Columns list changed in ZooKeeper. Applying changes locally.");
 
-                    if (changed_version)
-                        LOG_INFO(log, "ALTER-ing parts");
+                    storage.context.getDatabase(storage.database_name)->alterTable(
+                        storage.context, storage.table_name, columns_in_zk, {});
+                    storage.setColumns(std::move(columns_in_zk));
 
-                    int changed_parts = 0;
+                    /// Reinitialize primary key because primary key column types might have changed.
+                    storage.data.initPrimaryKey();
 
-                    if (!changed_version)
-                        parts = storage.data.getDataParts();
-
-                    const auto columns_for_parts = storage.getColumns().getAllPhysical();
-
-                    for (const MergeTreeData::DataPartPtr & part : parts)
-                    {
-                        /// Update the part and write result to temporary files.
-                        /// TODO: You can skip checking for too large changes if ZooKeeper has, for example,
-                        /// node /flags/force_alter.
-                        auto transaction = storage.data.alterDataPart(
-                            part, columns_for_parts, storage.data.primary_expr_ast, false);
-
-                        if (!transaction)
-                            continue;
-
-                        ++changed_parts;
-
-                        /// Update part metadata in ZooKeeper.
-                        zkutil::Requests ops;
-                        ops.emplace_back(zkutil::makeSetRequest(
-                            storage.replica_path + "/parts/" + part->name + "/columns", transaction->getNewColumns().toString(), -1));
-                        ops.emplace_back(zkutil::makeSetRequest(
-                            storage.replica_path + "/parts/" + part->name + "/checksums",
-                            storage.getChecksumsForZooKeeper(transaction->getNewChecksums()),
-                            -1));
-
-                        try
-                        {
-                            zookeeper->multi(ops);
-                        }
-                        catch (const zkutil::KeeperException & e)
-                        {
-                            /// The part does not exist in ZK. We will add to queue for verification - maybe the part is superfluous, and it must be removed locally.
-                            if (e.code == ZooKeeperImpl::ZooKeeper::ZNONODE)
-                                storage.enqueuePartForCheck(part->name);
-
-                            throw;
-                        }
-
-                        /// Apply file changes.
-                        transaction->commit();
-                    }
-
-                    /// Columns sizes could be quietly changed in case of MODIFY/ADD COLUMN
-                    storage.data.recalculateColumnSizes();
-
-                    /// List of columns for a specific replica.
-                    zookeeper->set(storage.replica_path + "/columns", columns_str);
-
-                    if (changed_version)
-                    {
-                        if (changed_parts != 0)
-                            LOG_INFO(log, "ALTER-ed " << changed_parts << " parts");
-                        else
-                            LOG_INFO(log, "No parts ALTER-ed");
-                    }
-
-                    force_recheck_parts = false;
+                    LOG_INFO(log, "Applied changes to table.");
+                }
+                else
+                {
+                    LOG_INFO(log, "Columns version changed in ZooKeeper, but data wasn't changed. It's like cyclic ALTERs.");
                 }
 
-                /// It's important that parts and merge_blocker are destroyed before the wait.
+                /// You need to get a list of parts under table lock to avoid race condition with merge.
+                parts = storage.data.getDataParts();
+
+                storage.columns_version = stat.version;
             }
 
-            wakeup_event->wait();
-        }
-        catch (const zkutil::KeeperException & e)
-        {
-            tryLogCurrentException(log, __PRETTY_FUNCTION__);
+            /// Update parts.
+            if (changed_version || force_recheck_parts)
+            {
+                auto table_lock = storage.lockStructure(false, __PRETTY_FUNCTION__);
 
-            if (e.code == ZooKeeperImpl::ZooKeeper::ZSESSIONEXPIRED)
-                break;
+                if (changed_version)
+                    LOG_INFO(log, "ALTER-ing parts");
 
-            force_recheck_parts = true;
-            wakeup_event->tryWait(ALTER_ERROR_SLEEP_MS);
-        }
-        catch (...)
-        {
-            tryLogCurrentException(log, __PRETTY_FUNCTION__);
+                int changed_parts = 0;
 
-            force_recheck_parts = true;
-            wakeup_event->tryWait(ALTER_ERROR_SLEEP_MS);
+                if (!changed_version)
+                    parts = storage.data.getDataParts();
+
+                const auto columns_for_parts = storage.getColumns().getAllPhysical();
+
+                for (const MergeTreeData::DataPartPtr & part : parts)
+                {
+                    /// Update the part and write result to temporary files.
+                    /// TODO: You can skip checking for too large changes if ZooKeeper has, for example,
+                    /// node /flags/force_alter.
+                    auto transaction = storage.data.alterDataPart(
+                        part, columns_for_parts, storage.data.primary_expr_ast, false);
+
+                    if (!transaction)
+                        continue;
+
+                    ++changed_parts;
+
+                    /// Update part metadata in ZooKeeper.
+                    zkutil::Requests ops;
+                    ops.emplace_back(zkutil::makeSetRequest(
+                        storage.replica_path + "/parts/" + part->name + "/columns", transaction->getNewColumns().toString(), -1));
+                    ops.emplace_back(zkutil::makeSetRequest(
+                        storage.replica_path + "/parts/" + part->name + "/checksums",
+                        storage.getChecksumsForZooKeeper(transaction->getNewChecksums()),
+                        -1));
+
+                    try
+                    {
+                        zookeeper->multi(ops);
+                    }
+                    catch (const zkutil::KeeperException & e)
+                    {
+                        /// The part does not exist in ZK. We will add to queue for verification - maybe the part is superfluous, and it must be removed locally.
+                        if (e.code == ZooKeeperImpl::ZooKeeper::ZNONODE)
+                            storage.enqueuePartForCheck(part->name);
+
+                        throw;
+                    }
+
+                    /// Apply file changes.
+                    transaction->commit();
+                }
+
+                /// Columns sizes could be quietly changed in case of MODIFY/ADD COLUMN
+                storage.data.recalculateColumnSizes();
+
+                /// List of columns for a specific replica.
+                zookeeper->set(storage.replica_path + "/columns", columns_str);
+
+                if (changed_version)
+                {
+                    if (changed_parts != 0)
+                        LOG_INFO(log, "ALTER-ed " << changed_parts << " parts");
+                    else
+                        LOG_INFO(log, "No parts ALTER-ed");
+                }
+
+                force_recheck_parts = false;
+            }
+
+            /// It's important that parts and merge_blocker are destroyed before the wait.
         }
     }
+    catch (const zkutil::KeeperException & e)
+    {
+        tryLogCurrentException(log, __PRETTY_FUNCTION__);
 
-    LOG_DEBUG(log, "Alter thread finished");
+        if (e.code == ZooKeeperImpl::ZooKeeper::ZSESSIONEXPIRED)
+            return;
+
+        force_recheck_parts = true;
+        task_handle->scheduleAfter(ALTER_ERROR_SLEEP_MS);
+    }
+    catch (...)
+    {
+        tryLogCurrentException(log, __PRETTY_FUNCTION__);
+
+        force_recheck_parts = true;
+        task_handle->scheduleAfter(ALTER_ERROR_SLEEP_MS);
+    }
 }
 
 }

dbms/src/Storages/MergeTree/ReplicatedMergeTreeAlterThread.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <thread>
+#include <Common/BackgroundSchedulePool.h>
 #include <Common/ZooKeeper/Types.h>
 #include <Core/Types.h>
 #include <common/logger_useful.h>
@@ -21,25 +22,14 @@ class ReplicatedMergeTreeAlterThread
 {
 public:
     ReplicatedMergeTreeAlterThread(StorageReplicatedMergeTree & storage_);
-
-    ~ReplicatedMergeTreeAlterThread()
-    {
-        need_stop = true;
-        wakeup_event->set();
-        if (thread.joinable())
-            thread.join();
-    }
+    ~ReplicatedMergeTreeAlterThread();
 
 private:
     void run();
 
     StorageReplicatedMergeTree & storage;
     Logger * log;
-
-    zkutil::EventPtr wakeup_event { std::make_shared<Poco::Event>() };
-    std::atomic<bool> need_stop { false };
-
-    std::thread thread;
+    BackgroundSchedulePool::TaskHandle task_handle;
 };
 
 }

dbms/src/Storages/MergeTree/ReplicatedMergeTreeBlockOutputStream.cpp

@@ -108,7 +108,7 @@ void ReplicatedMergeTreeBlockOutputStream::write(const Block & block)
     last_block_is_duplicate = false;
 
     /// TODO Is it possible to not lock the table structure here?
-    storage.data.delayInsertIfNeeded(&storage.restarting_thread->getWakeupEvent());
+    storage.data.delayInsertOrThrowIfNeeded(&storage.restarting_thread->getWakeupEvent());
 
     auto zookeeper = storage.getZooKeeper();
     assertSessionIsNotExpired(zookeeper);
@@ -161,11 +161,11 @@ void ReplicatedMergeTreeBlockOutputStream::write(const Block & block)
 
             /// Set a special error code if the block is duplicate
             int error = (deduplicate && last_block_is_duplicate) ? ErrorCodes::INSERT_WAS_DEDUPLICATED : 0;
-            PartLog::addNewPartToTheLog(storage.context, *part, watch.elapsed(), ExecutionStatus(error));
+            PartLog::addNewPart(storage.context, part, watch.elapsed(), ExecutionStatus(error));
         }
         catch (...)
         {
-            PartLog::addNewPartToTheLog(storage.context, *part, watch.elapsed(), ExecutionStatus::fromCurrentException(__PRETTY_FUNCTION__));
+            PartLog::addNewPart(storage.context, part, watch.elapsed(), ExecutionStatus::fromCurrentException(__PRETTY_FUNCTION__));
             throw;
         }
     }
@@ -176,7 +176,7 @@ void ReplicatedMergeTreeBlockOutputStream::writeExistingPart(MergeTreeData::Muta
 {
     last_block_is_duplicate = false;
 
-    /// NOTE No delay in this case. That's Ok.
+    /// NOTE: No delay in this case. That's Ok.
 
     auto zookeeper = storage.getZooKeeper();
     assertSessionIsNotExpired(zookeeper);
@@ -189,11 +189,11 @@ void ReplicatedMergeTreeBlockOutputStream::writeExistingPart(MergeTreeData::Muta
     try
     {
         commitPart(zookeeper, part, "");
-        PartLog::addNewPartToTheLog(storage.context, *part, watch.elapsed());
+        PartLog::addNewPart(storage.context, part, watch.elapsed());
     }
     catch (...)
     {
-        PartLog::addNewPartToTheLog(storage.context, *part, watch.elapsed(), ExecutionStatus::fromCurrentException(__PRETTY_FUNCTION__));
+        PartLog::addNewPart(storage.context, part, watch.elapsed(), ExecutionStatus::fromCurrentException(__PRETTY_FUNCTION__));
         throw;
     }
 }
@@ -208,47 +208,20 @@ void ReplicatedMergeTreeBlockOutputStream::commitPart(zkutil::ZooKeeperPtr & zoo
     /// We remove the lock just after renaming the part. In case of exception, block number will be marked as abandoned.
     /// Also, make deduplication check. If a duplicate is detected, no nodes are created.
 
-    /// Deduplication stuff
+    /// Allocate new block number and check for duplicates
     bool deduplicate_block = !block_id.empty();
-    String block_id_path;
-    zkutil::Requests deduplication_check_ops;
-    zkutil::Requests * deduplication_check_ops_ptr = nullptr;
+    String block_id_path = deduplicate_block ? storage.zookeeper_path + "/blocks/" + block_id : "";
+    auto block_number_lock = storage.allocateBlockNumber(part->info.partition_id, zookeeper, block_id_path);
 
-    if (deduplicate_block)
+    if (!block_number_lock)
     {
-        block_id_path = storage.zookeeper_path + "/blocks/" + block_id;
-
-        /// Lets check for duplicates in advance, to avoid superflous block numbers allocation
-        deduplication_check_ops.emplace_back(zkutil::makeCreateRequest(block_id_path, "", zkutil::CreateMode::Persistent));
-        deduplication_check_ops.emplace_back(zkutil::makeRemoveRequest(block_id_path, -1));
-        deduplication_check_ops_ptr = &deduplication_check_ops;
+        part->is_duplicate = true;
+        last_block_is_duplicate = true;
+        ProfileEvents::increment(ProfileEvents::DuplicatedInsertedBlocks);
+        return;
     }
 
-    AbandonableLockInZooKeeper block_number_lock;
-    try
-    {
-        /// 2 RTT
-        block_number_lock = storage.allocateBlockNumber(part->info.partition_id, zookeeper, deduplication_check_ops_ptr);
-    }
-    catch (const zkutil::KeeperMultiException & e)
-    {
-        if (deduplicate_block && e.code == ZooKeeperImpl::ZooKeeper::ZNODEEXISTS && e.getPathForFirstFailedOp() == block_id_path)
-        {
-            LOG_INFO(log, "Block with ID " << block_id << " already exists; ignoring it (skip the insertion)");
-            part->is_duplicate = true;
-            last_block_is_duplicate = true;
-            ProfileEvents::increment(ProfileEvents::DuplicatedInsertedBlocks);
-            return;
-        }
-
-        throw Exception("Cannot allocate block number in ZooKeeper: " + e.displayText(), ErrorCodes::KEEPER_EXCEPTION);
-    }
-    catch (const zkutil::KeeperException & e)
-    {
-        throw Exception("Cannot allocate block number in ZooKeeper: " + e.displayText(), ErrorCodes::KEEPER_EXCEPTION);
-    }
-
-    Int64 block_number = block_number_lock.getNumber();
+    Int64 block_number = block_number_lock->getNumber();
 
     /// Set part attributes according to part_number. Prepare an entry for log.
 
@@ -277,33 +250,7 @@ void ReplicatedMergeTreeBlockOutputStream::commitPart(zkutil::ZooKeeperPtr & zoo
     /// Information about the part.
     zkutil::Requests ops;
 
-    if (deduplicate_block)
-    {
-        /// Make final duplicate check and commit block_id
-        ops.emplace_back(
-            zkutil::makeCreateRequest(
-                block_id_path,
-                toString(block_number),  /// We will able to know original part number for duplicate blocks, if we want.
-                zkutil::CreateMode::Persistent));
-    }
-
-    /// Information about the part, in the replica data.
-
-    ops.emplace_back(zkutil::makeCheckRequest(
-        storage.zookeeper_path + "/columns",
-        storage.columns_version));
-    ops.emplace_back(zkutil::makeCreateRequest(
-        storage.replica_path + "/parts/" + part->name,
-        "",
-        zkutil::CreateMode::Persistent));
-    ops.emplace_back(zkutil::makeCreateRequest(
-        storage.replica_path + "/parts/" + part->name + "/columns",
-        part->columns.toString(),
-        zkutil::CreateMode::Persistent));
-    ops.emplace_back(zkutil::makeCreateRequest(
-        storage.replica_path + "/parts/" + part->name + "/checksums",
-        storage.getChecksumsForZooKeeper(part->checksums),
-        zkutil::CreateMode::Persistent));
+    storage.getCommitPartOps(ops, part, block_id_path);
 
     /// Replication log.
     ops.emplace_back(zkutil::makeCreateRequest(
@@ -312,7 +259,7 @@ void ReplicatedMergeTreeBlockOutputStream::commitPart(zkutil::ZooKeeperPtr & zoo
         zkutil::CreateMode::PersistentSequential));
 
     /// Deletes the information that the block number is used for writing.
-    block_number_lock.getUnlockOps(ops);
+    block_number_lock->getUnlockOps(ops);
 
     /** If you need a quorum - create a node in which the quorum is monitored.
         * (If such a node already exists, then someone has managed to make another quorum record at the same time, but for it the quorum has not yet been reached.
@@ -362,10 +309,10 @@ void ReplicatedMergeTreeBlockOutputStream::commitPart(zkutil::ZooKeeperPtr & zoo
     if (multi_code == ZooKeeperImpl::ZooKeeper::ZOK)
     {
         transaction.commit();
-        storage.merge_selecting_event.set();
+        storage.merge_selecting_task_handle->schedule();
 
         /// Lock nodes have been already deleted, do not delete them in destructor
-        block_number_lock.assumeUnlocked();
+        block_number_lock->assumeUnlocked();
     }
     else if (zkutil::isUserError(multi_code))
     {
@@ -455,5 +402,10 @@ void ReplicatedMergeTreeBlockOutputStream::commitPart(zkutil::ZooKeeperPtr & zoo
     }
 }
 
+void ReplicatedMergeTreeBlockOutputStream::writePrefix()
+{
+    storage.data.throwInsertIfNeeded();
+}
+
 
 }

dbms/src/Storages/MergeTree/ReplicatedMergeTreeBlockOutputStream.h

@@ -26,6 +26,7 @@ public:
                                          bool deduplicate_);
 
     Block getHeader() const override;
+    void writePrefix() override;
     void write(const Block & block) override;
 
     /// For ATTACHing existing data on filesystem.

dbms/src/Storages/MergeTree/ReplicatedMergeTreeCleanupThread.cpp

@@ -17,41 +17,40 @@ namespace ErrorCodes
 
 ReplicatedMergeTreeCleanupThread::ReplicatedMergeTreeCleanupThread(StorageReplicatedMergeTree & storage_)
     : storage(storage_),
-    log(&Logger::get(storage.database_name + "." + storage.table_name + " (StorageReplicatedMergeTree, CleanupThread)")),
-    thread([this] { run(); })
+    log(&Logger::get(storage.database_name + "." + storage.table_name + " (StorageReplicatedMergeTree, CleanupThread)"))
 {
+    task_handle = storage.context.getSchedulePool().addTask("ReplicatedMergeTreeCleanupThread", [this]{ run(); });
+    task_handle->schedule();
 }
 
+ReplicatedMergeTreeCleanupThread::~ReplicatedMergeTreeCleanupThread()
+{
+    storage.context.getSchedulePool().removeTask(task_handle);
+}
 
 void ReplicatedMergeTreeCleanupThread::run()
 {
-    setThreadName("ReplMTCleanup");
-
     const auto CLEANUP_SLEEP_MS = storage.data.settings.cleanup_delay_period * 1000
         + std::uniform_int_distribution<UInt64>(0, storage.data.settings.cleanup_delay_period_random_add * 1000)(rng);
 
-    while (!storage.shutdown_called)
+    try
     {
-        try
-        {
-            iterate();
-        }
-        catch (const zkutil::KeeperException & e)
-        {
-            tryLogCurrentException(log, __PRETTY_FUNCTION__);
+        iterate();
+    }
+    catch (const zkutil::KeeperException & e)
+    {
+        tryLogCurrentException(log, __PRETTY_FUNCTION__);
 
-            if (e.code == ZooKeeperImpl::ZooKeeper::ZSESSIONEXPIRED)
-                break;
-        }
-        catch (...)
-        {
-            tryLogCurrentException(log, __PRETTY_FUNCTION__);
-        }
-
-        storage.cleanup_thread_event.tryWait(CLEANUP_SLEEP_MS);
+        if (e.code == ZooKeeperImpl::ZooKeeper::ZSESSIONEXPIRED)
+            return;
+    }
+    catch (...)
+    {
+        tryLogCurrentException(log, __PRETTY_FUNCTION__);
     }
 
-    LOG_DEBUG(log, "Cleanup thread finished");
+    task_handle->scheduleAfter(CLEANUP_SLEEP_MS);
+
 }
 
 
@@ -243,11 +242,4 @@ void ReplicatedMergeTreeCleanupThread::getBlocksSortedByTime(zkutil::ZooKeeper &
     std::sort(timed_blocks.begin(), timed_blocks.end(), NodeWithStat::greaterByTime);
 }
 
-
-ReplicatedMergeTreeCleanupThread::~ReplicatedMergeTreeCleanupThread()
-{
-    if (thread.joinable())
-        thread.join();
-}
-
 }

dbms/src/Storages/MergeTree/ReplicatedMergeTreeCleanupThread.h

@@ -4,6 +4,7 @@
 #include <Common/ZooKeeper/Types.h>
 #include <Common/ZooKeeper/ZooKeeper.h>
 #include <common/logger_useful.h>
+#include <Common/BackgroundSchedulePool.h>
 #include <thread>
 #include <map>
 
@@ -25,10 +26,12 @@ public:
 
     ~ReplicatedMergeTreeCleanupThread();
 
+    void schedule() { task_handle->schedule(); }
+
 private:
     StorageReplicatedMergeTree & storage;
     Logger * log;
-    std::thread thread;
+    BackgroundSchedulePool::TaskHandle task_handle;
     pcg64 rng;
 
     void run();