Add allow without connection setting to MaterializedMySQLSettings

kirillgarbar · May 6, 2024 · a20ef2a · a20ef2a
1 parent cb4f78d
commit a20ef2a
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Showing 4 changed files with 23 additions and 2 deletions.
diff --git a/docs/en/engines/database-engines/materialized-mysql.md b/docs/en/engines/database-engines/materialized-mysql.md
@@ -51,6 +51,9 @@ ENGINE = MaterializedMySQL('host:port', ['database' | database], 'user', 'passwo
 ### allows_query_when_mysql_lost
 `allows_query_when_mysql_lost` — Allows to query a materialized table when MySQL is lost. Default: `0` (`false`).
 
+### allow_startup_database_without_connection_to_mysql
+`allow_startup_database_without_connection_to_mysql` — Allow to create and attach database without available connection to MySQL. Default: `0` (`false`).
+
 ### materialized_mysql_tables_list
 
 `materialized_mysql_tables_list` — a comma-separated list of mysql database tables, which will be replicated by MaterializedMySQL database engine. Default value: empty list — means whole tables will be replicated.

diff --git a/src/Databases/MySQL/DatabaseMaterializedMySQL.cpp b/src/Databases/MySQL/DatabaseMaterializedMySQL.cpp
@@ -81,9 +81,13 @@ LoadTaskPtr DatabaseMaterializedMySQL::startupDatabaseAsync(AsyncLoader & async_
         base->goals(),
         TablesLoaderBackgroundStartupPoolId,
         fmt::format("startup MaterializedMySQL database {}", getDatabaseName()),
-        [this] (AsyncLoader &, const LoadJobPtr &)
+        [this, mode] (AsyncLoader &, const LoadJobPtr &)
         {
             LOG_TRACE(log, "Starting MaterializeMySQL database");
+            if (!settings->allow_startup_database_without_connection_to_mysql
+                && mode < LoadingStrictnessLevel::FORCE_ATTACH)
+                materialize_thread.assertMySQLAvailable();
+
             materialize_thread.startSynchronization();
             started_up = true;
         });

diff --git a/src/Databases/MySQL/MaterializedMySQLSettings.h b/src/Databases/MySQL/MaterializedMySQLSettings.h
@@ -22,6 +22,7 @@ class ASTStorage;
     M(UInt64, max_milliseconds_to_wait_in_binlog_queue, 10000, "Max milliseconds to wait when max bytes exceeded in a binlog queue.", 0) \
     M(UInt64, max_bytes_in_binlog_dispatcher_buffer, DBMS_DEFAULT_BUFFER_SIZE, "Max bytes in the binlog dispatcher's buffer before it is flushed to attached binlogs.", 0) \
     M(UInt64, max_flush_milliseconds_in_binlog_dispatcher, 1000, "Max milliseconds in the binlog dispatcher's buffer to wait before it is flushed to attached binlogs.", 0) \
+    M(Bool, allow_startup_database_without_connection_to_mysql, false, "Allow to create and attach database without available connection to MySQL.", 0) \
 
     DECLARE_SETTINGS_TRAITS(MaterializedMySQLSettingsTraits, LIST_OF_MATERIALIZE_MODE_SETTINGS)
 

diff --git a/tests/integration/test_materialized_mysql_database/materialized_with_ddl.py b/tests/integration/test_materialized_mysql_database/materialized_with_ddl.py
@@ -3425,8 +3425,21 @@ def mysql_create_database_without_connection(clickhouse_node, mysql_node, servic
 
     clickhouse_node.cluster.pause_container(service_name)
 
+    assert "ConnectionFailed:" in clickhouse_node.query_and_get_error(
+        """
+        CREATE DATABASE create_without_connection
+        ENGINE = MaterializedMySQL('{}:3306', 'create_without_connection', 'root', 'clickhouse')
+        """.format(
+            service_name
+        )
+    )
+
     clickhouse_node.query(
-        "CREATE DATABASE create_without_connection ENGINE = MaterializedMySQL('{}:3306', 'create_without_connection', 'root', 'clickhouse') SETTINGS max_wait_time_when_mysql_unavailable=-1".format(
+        """
+        CREATE DATABASE create_without_connection
+        ENGINE = MaterializedMySQL('{}:3306', 'create_without_connection', 'root', 'clickhouse')
+        SETTINGS allow_startup_database_without_connection_to_mysql=1
+        """.format(
             service_name
         )
     )