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Merge pull request #7717 from MaxFedotov/support_mysql_federated

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support clickhouse as mysql federated server
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alexey-milovidov 2019-12-03 02:21:35 +03:00 committed by GitHub
commit 43c47bdb55
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4 changed files with 108 additions and 21 deletions
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86
dbms/programs/server/MySQLHandler.cpp
View File

@ -15,6 +15,7 @@
#include <IO/ReadBufferFromString.h>
#include <IO/WriteBufferFromPocoSocket.h>
#include <Storages/IStorage.h>
#include <boost/algorithm/string/replace.hpp>
#if USE_POCO_NETSSL
#include <Poco/Net/SecureStreamSocket.h>
@ -267,29 +268,49 @@ void MySQLHandler::comPing()
packet_sender->sendPacket(OK_Packet(0x0, client_capability_flags, 0, 0, 0), true);
}
static bool isFederatedServerSetupCommand(const String & query);
void MySQLHandler::comQuery(ReadBuffer & payload)
{
bool with_output = false;
std::function<void(const String &)> set_content_type = [&with_output](const String &) -> void {
with_output = true;
};
String query = String(payload.position(), payload.buffer().end());
const String query("select ''");
ReadBufferFromString empty_select(query);
bool should_replace = false;
// Translate query from MySQL to ClickHouse.
// This is a temporary workaround until ClickHouse supports the syntax "@@var_name".
if (std::string(payload.position(), payload.buffer().end()) == "select @@version_comment limit 1") // MariaDB client starts session with that query
// This is a workaround in order to support adding ClickHouse to MySQL using federated server.
// As Clickhouse doesn't support these statements, we just send OK packet in response.
if (isFederatedServerSetupCommand(query))
{
should_replace = true;
}
Context query_context = connection_context;
executeQuery(should_replace ? empty_select : payload, *out, true, query_context, set_content_type, nullptr);
if (!with_output)
packet_sender->sendPacket(OK_Packet(0x00, client_capability_flags, 0, 0, 0), true);
}
else
{
bool with_output = false;
std::function<void(const String &)> set_content_type = [&with_output](const String &) -> void {
with_output = true;
};
String replacement_query = "select ''";
bool should_replace = false;
// Translate query from MySQL to ClickHouse.
// This is a temporary workaround until ClickHouse supports the syntax "@@var_name".
if (query == "select @@version_comment limit 1") // MariaDB client starts session with that query
{
should_replace = true;
}
// This is a workaround in order to support adding ClickHouse to MySQL using federated server.
if (0 == strncasecmp("SHOW TABLE STATUS LIKE", query.c_str(), 22))
{
should_replace = true;
replacement_query = boost::replace_all_copy(query, "SHOW TABLE STATUS LIKE ", show_table_status_replacement_query);
}
ReadBufferFromString replacement(replacement_query);
Context query_context = connection_context;
executeQuery(should_replace ? replacement : payload, *out, true, query_context, set_content_type, nullptr);
if (!with_output)
packet_sender->sendPacket(OK_Packet(0x00, client_capability_flags, 0, 0, 0), true);
}
}
void MySQLHandler::authPluginSSL()
@ -335,4 +356,33 @@ void MySQLHandlerSSL::finishHandshakeSSL(size_t packet_size, char * buf, size_t
#endif
static bool isFederatedServerSetupCommand(const String & query)
{
return 0 == strncasecmp("SET NAMES", query.c_str(), 9) || 0 == strncasecmp("SET character_set_results", query.c_str(), 25)
|| 0 == strncasecmp("SET FOREIGN_KEY_CHECKS", query.c_str(), 22) || 0 == strncasecmp("SET AUTOCOMMIT", query.c_str(), 14)
|| 0 == strncasecmp("SET SESSION TRANSACTION ISOLATION LEVEL", query.c_str(), 39);
}
const String MySQLHandler::show_table_status_replacement_query("SELECT"
" name AS Name,"
" engine AS Engine,"
" '10' AS Version,"
" 'Dynamic' AS Row_format,"
" 0 AS Rows,"
" 0 AS Avg_row_length,"
" 0 AS Data_length,"
" 0 AS Max_data_length,"
" 0 AS Index_length,"
" 0 AS Data_free,"
" 'NULL' AS Auto_increment,"
" metadata_modification_time AS Create_time,"
" metadata_modification_time AS Update_time,"
" metadata_modification_time AS Check_time,"
" 'utf8_bin' AS Collation,"
" 'NULL' AS Checksum,"
" '' AS Create_options,"
" '' AS Comment"
" FROM system.tables"
" WHERE name LIKE ");
}

4
dbms/programs/server/MySQLHandler.h
View File

@ -11,7 +11,6 @@
namespace DB
{
/// Handler for MySQL wire protocol connections. Allows to connect to ClickHouse using MySQL client.
class MySQLHandler : public Poco::Net::TCPServerConnection
{
@ -59,6 +58,9 @@ protected:
std::shared_ptr<WriteBuffer> out;
bool secure_connection = false;
private:
static const String show_table_status_replacement_query;
};
#if USE_SSL && USE_POCO_NETSSL

6
dbms/tests/integration/test_mysql_protocol/clients/mysql/docker_compose.yml
View File

@ -2,5 +2,7 @@ version: '2.2'
services:
mysql1:
image: mysql:5.7
# rewriting default command, because starting server is unnecessary
command: sleep infinity
restart: always
environment:
MYSQL_ALLOW_EMPTY_PASSWORD: 1
command: --federated --socket /var/run/mysqld/mysqld.sock

33
dbms/tests/integration/test_mysql_protocol/test.py
View File

@ -108,6 +108,39 @@ def test_mysql_client(mysql_client, server_address):
assert stdout == '\n'.join(['column', '0', '0', '1', '1', '5', '5', 'tmp_column', '0', '1', ''])
def test_mysql_federated(mysql_client, server_address):
node.query('''DROP DATABASE IF EXISTS mysql_federated''', settings={"password": "123"})
node.query('''CREATE DATABASE mysql_federated''', settings={"password": "123"})
node.query('''CREATE TABLE mysql_federated.test (col UInt32) ENGINE = Log''', settings={"password": "123"})
node.query('''INSERT INTO mysql_federated.test VALUES (0), (1), (5)''', settings={"password": "123"})
code, (_, stderr) = mysql_client.exec_run('''
mysql
-e "DROP SERVER IF EXISTS clickhouse;"
-e "CREATE SERVER clickhouse FOREIGN DATA WRAPPER mysql OPTIONS (USER 'default', PASSWORD '123', HOST '{host}', PORT {port}, DATABASE 'mysql_federated');"
-e "DROP DATABASE IF EXISTS mysql_federated;"
-e "CREATE DATABASE mysql_federated;"
'''.format(host=server_address, port=server_port), demux=True)
assert code == 0
code, (stdout, stderr) = mysql_client.exec_run('''
mysql
-e "CREATE TABLE mysql_federated.test(`col` int UNSIGNED) ENGINE=FEDERATED CONNECTION='clickhouse';"
-e "SELECT * FROM mysql_federated.test ORDER BY col;"
'''.format(host=server_address, port=server_port), demux=True)
assert stdout == '\n'.join(['col', '0', '1', '5', ''])
code, (stdout, stderr) = mysql_client.exec_run('''
mysql
-e "INSERT INTO mysql_federated.test VALUES (0), (1), (5);"
-e "SELECT * FROM mysql_federated.test ORDER BY col;"
'''.format(host=server_address, port=server_port), demux=True)
assert stdout == '\n'.join(['col', '0', '0', '1', '1', '5', '5', ''])
def test_python_client(server_address):
client = pymysql.connections.Connection(host=server_address, user='user_with_double_sha1', password='abacaba', database='default', port=server_port)