Configuring, starting, and stopping binary log (binlog) replication

The following stored procedures control how transactions are replicated from an external database into RDS for MySQL, or from RDS for MySQL to an external database.

mysql.rds_next_master_log

Changes the source database instance log position to the start of the next binary log on the source database instance. Use this procedure only if you are receiving replication I/O error 1236 on a read replica.

Syntax

CALL mysql.rds_next_master_log(
curr_master_log
);

Parameters

Usage notes

The master user must run the mysql.rds_next_master_log procedure.

Examples

Assume replication fails on an RDS for MySQL read replica. Running SHOW REPLICA STATUS\G on the read replica returns the following result:

*************************** 1. row ***************************
             Replica_IO_State:
                  Source_Host: myhost.XXXXXXXXXXXXXXX.rr-rrrr-1.rds.amazonaws.com
                  Source_User: MasterUser
                  Source_Port: 3306
                Connect_Retry: 10
              Source_Log_File: mysql-bin-changelog.012345
          Read_Source_Log_Pos: 1219393
               Relay_Log_File: relaylog.012340
                Relay_Log_Pos: 30223388
        Relay_Source_Log_File: mysql-bin-changelog.012345
           Replica_IO_Running: No
          Replica_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB:
           Replicate_Do_Table:
       Replicate_Ignore_Table:
      Replicate_Wild_Do_Table:
  Replicate_Wild_Ignore_Table:
                   Last_Errno: 0
                   Last_Error:
                 Skip_Counter: 0
          Exec_Source_Log_Pos: 30223232
              Relay_Log_Space: 5248928866
              Until_Condition: None
               Until_Log_File:
                Until_Log_Pos: 0
           Source_SSL_Allowed: No
           Source_SSL_CA_File:
           Source_SSL_CA_Path:
              Source_SSL_Cert:
            Source_SSL_Cipher:
               Source_SSL_Key:
        Seconds_Behind_Master: NULL
Source_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 1236
                Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Client requested master to start replication from impossible position; the first event 'mysql-bin-changelog.013406' at 1219393, the last event read from '/rdsdbdata/log/binlog/mysql-bin-changelog.012345' at 4, the last byte read from '/rdsdbdata/log/binlog/mysql-bin-changelog.012345' at 4.'
               Last_SQL_Errno: 0
               Last_SQL_Error:
  Replicate_Ignore_Server_Ids:
             Source_Server_Id: 67285976

The Last_IO_Errno field shows that the instance is receiving I/O error 1236. The Master_Log_File field shows that the file name is mysql-bin-changelog.012345, which means that the log file index is 12345. To resolve the error, you can call mysql.rds_next_master_log with the following parameter:

CALL mysql.rds_next_master_log(12345);

mysql.rds_reset_external_master

Reconfigures an RDS for MySQL DB instance to no longer be a read replica of an instance of MySQL running external to Amazon RDS.

Syntax

CALL mysql.rds_reset_external_master;

Usage notes

The master user must run the mysql.rds_reset_external_master procedure. This procedure must be run on the MySQL DB instance to be removed as a read replica of a MySQL instance running external to Amazon RDS.

For more information about using replication to import data from an instance of MySQL running external to Amazon RDS, see Configuring binary log file position replication with an external source instance.

mysql.rds_set_external_master

Configures an RDS for MySQL DB instance to be a read replica of an instance of MySQL running external to Amazon RDS.

Syntax

CALL mysql.rds_set_external_master (
  host_name
  , host_port
  , replication_user_name
  , replication_user_password
  , mysql_binary_log_file_name
  , mysql_binary_log_file_location
  , ssl_encryption
);

Parameters

Usage notes

The master user must run the mysql.rds_set_external_master procedure. This procedure must be run on the MySQL DB instance to be configured as the read replica of a MySQL instance running external to Amazon RDS.

Before you run mysql.rds_set_external_master, you must configure the instance of MySQL running external to Amazon RDS to be a source database instance. To connect to the MySQL instance running external to Amazon RDS, you must specify replication_user_name and replication_user_password values that indicate a replication user that has REPLICATION CLIENT and REPLICATION SLAVE permissions on the external instance of MySQL.

To use encrypted replication, configure source database instance to use SSL connections.

After calling mysql.rds_set_external_master to configure an Amazon RDS DB instance as a read replica, you can call mysql.rds_start_replication on the read replica to start the replication process. You can call mysql.rds_reset_external_master to remove the read replica configuration.

When mysql.rds_set_external_master is called, Amazon RDS records the time, user, and an action of set master in the mysql.rds_history and mysql.rds_replication_status tables.

Examples

When run on a MySQL DB instance, the following example configures the DB instance to be a read replica of an instance of MySQL running external to Amazon RDS.

call mysql.rds_set_external_master(
  'Externaldb.some.com',
  3306,
  'repl_user',
  'password',
  'mysql-bin-changelog.0777',
  120,
  0);

mysql.rds_set_external_master_with_auto_position

Configures an RDS for MySQL DB instance to be a read replica of an instance of MySQL running external to Amazon RDS. This procedure also configures delayed replication and replication based on global transaction identifiers (GTIDs).

Syntax

CALL mysql.rds_set_external_master_with_auto_position (
  host_name
  , host_port
  , replication_user_name
  , replication_user_password
  , ssl_encryption
  , delay
);

Parameters

Usage notes

The master user must run the mysql.rds_set_external_master_with_auto_position procedure. This procedure must be run on the MySQL DB instance to be configured as the read replica of a MySQL instance running external to Amazon RDS.

This procedure is supported for all RDS for MySQL 5.7 versions, and RDS for MySQL 8.0.26 and higher 8.0 versions.

Before you run mysql.rds_set_external_master_with_auto_position, you must configure the instance of MySQL running external to Amazon RDS to be a source database instance. To connect to the MySQL instance running external to Amazon RDS, you must specify values for replication_user_name and replication_user_password. These values must indicate a replication user that has REPLICATION CLIENT and REPLICATION SLAVE permissions on the external instance of MySQL.

For more information, see Configuring binary log file position replication with an external source instance.

Before you call mysql.rds_set_external_master_with_auto_position, make sure to call mysql.rds_set_external_source_gtid_purged to set the gtid_purged system variable with a specified GTID range from an external source.

After calling mysql.rds_set_external_master_with_auto_position to configure an Amazon RDS DB instance as a read replica, you can call mysql.rds_start_replication on the read replica to start the replication process. You can call mysql.rds_reset_external_master to remove the read replica configuration.

When you call mysql.rds_set_external_master_with_auto_position, Amazon RDS records the time, the user, and an action of set master in the mysql.rds_history and mysql.rds_replication_status tables.

For disaster recovery, you can use this procedure with the mysql.rds_start_replication_until or mysql.rds_start_replication_until_gtid stored procedure. To roll forward changes to a delayed read replica to the time just before a disaster, you can run the mysql.rds_set_external_master_with_auto_position procedure. After the mysql.rds_start_replication_until_gtid procedure stops replication, you can promote the read replica to be the new primary DB instance by using the instructions in Promoting a read replica to be a standalone DB instance.

To use the mysql.rds_rds_start_replication_until_gtid procedure, GTID-based replication must be enabled. To skip a specific GTID-based transaction that is known to cause disaster, you can use the mysql.rds_skip_transaction_with_gtid stored procedure. For more information about working with GTID-based replication, see Using GTID-based replication.

Examples

When run on a MySQL DB instance, the following example configures the DB instance to be a read replica of an instance of MySQL running external to Amazon RDS. It sets the minimum replication delay to one hour (3,600 seconds) on the MySQL DB instance. A change from the MySQL source database instance running external to Amazon RDS isn't applied on the MySQL DB instance read replica for at least one hour.

call mysql.rds_set_external_master_with_auto_position(
  'Externaldb.some.com',
  3306,
  'repl_user',
  'SomePassW0rd',
  0,
  3600);

mysql.rds_set_external_master_with_delay

Configures an RDS for MySQL DB instance to be a read replica of an instance of MySQL running external to Amazon RDS and configures delayed replication.

Syntax

CALL mysql.rds_set_external_master_with_delay(
  host_name
  , host_port
  , replication_user_name
  , replication_user_password
  , mysql_binary_log_file_name
  , mysql_binary_log_file_location
  , ssl_encryption
  , delay
);

Parameters

Usage notes

The master user must run the mysql.rds_set_external_master_with_delay procedure. This procedure must be run on the MySQL DB instance to be configured as the read replica of a MySQL instance running external to Amazon RDS.

Before you run mysql.rds_set_external_master_with_delay, you must configure the instance of MySQL running external to Amazon RDS to be a source database instance. To connect to the MySQL instance running external to Amazon RDS, you must specify values for replication_user_name and replication_user_password. These values must indicate a replication user that has REPLICATION CLIENT and REPLICATION SLAVE permissions on the external instance of MySQL.

For more information, see Configuring binary log file position replication with an external source instance.

After calling mysql.rds_set_external_master_with_delay to configure an Amazon RDS DB instance as a read replica, you can call mysql.rds_start_replication on the read replica to start the replication process. You can call mysql.rds_reset_external_master to remove the read replica configuration.

When you call mysql.rds_set_external_master_with_delay, Amazon RDS records the time, the user, and an action of set master in the mysql.rds_history and mysql.rds_replication_status tables.

For disaster recovery, you can use this procedure with the mysql.rds_start_replication_until or mysql.rds_start_replication_until_gtid stored procedure. To roll forward changes to a delayed read replica to the time just before a disaster, you can run the mysql.rds_set_external_master_with_delay procedure. After the mysql.rds_start_replication_until procedure stops replication, you can promote the read replica to be the new primary DB instance by using the instructions in Promoting a read replica to be a standalone DB instance.

To use the mysql.rds_rds_start_replication_until_gtid procedure, GTID-based replication must be enabled. To skip a specific GTID-based transaction that is known to cause disaster, you can use the mysql.rds_skip_transaction_with_gtid stored procedure. For more information about working with GTID-based replication, see Using GTID-based replication.

The mysql.rds_set_external_master_with_delay procedure is available in these versions of RDS for MySQL:

Examples

When run on a MySQL DB instance, the following example configures the DB instance to be a read replica of an instance of MySQL running external to Amazon RDS. It sets the minimum replication delay to one hour (3,600 seconds) on the MySQL DB instance. A change from the MySQL source database instance running external to Amazon RDS isn't applied on the MySQL DB instance read replica for at least one hour.

call mysql.rds_set_external_master_with_delay(
  'Externaldb.some.com',
  3306,
  'repl_user',
  'SomePassW0rd',
  'mysql-bin-changelog.000777',
  120,
  0,
  3600);

mysql.rds_set_external_source_gtid_purged

Sets the gtid_purged system variable with a specified GTID range from an external source. The gtid_purged value is required for configuring GTID-based replication to resume the replication using auto positioning.

Syntax

CALL mysql.rds_set_external_source_gtid_purged(
  server_uuid
  , start_pos
  , end_pos
);

Parameters

Usage notes

The mysql.rds_set_external_source_gtid_purged procedure is only available with MySQL 8.0.37 and higher 8.0 versions.

Call mysql.rds_set_external_source_gtid_purged before you call mysql.rds_set_external_master_with_auto_position or mysql.rds_set_external_source_with_auto_position_for_channel.

Before you call mysql.rds_set_external_source_gtid_purged, make sure to stop all active replication channels for the database. To check the status of a channel, use the SHOW REPLICA STATUS MySQL statement. To stop replication on a channel, call mysql.rds_stop_replication_for_channel.

The GTID range that you specify must be a superset of the existing GTID_PURGED value. This stored procedure checks the following values before it sets the GTID_PURGED value:

If the GTID set on your external server contains multiple ranges of values, consider calling the procedure multiple times with different GTID set values.

When you call mysql.rds_set_external_source_gtid_purged, Amazon RDS records the time, the user, and an action of set gtid_purged in the mysql.rds_history table.

If you don't set the gtid_purged value appropriately for the backup that you use for replication, this can result in missing or duplicated transactions during the replication process. Perform the following steps to set the correct gtid_purged value.

Examples

When run on a MySQL DB instance, the following example sets the GTID range from an external MySQL server with the UUID 12345678-abcd-1234-efgh-123456789abc, a starting position of 1, and an ending position of 100. The resulting GTID value is set to +12345678-abcd-1234-efgh-123456789abc:1-100.

CALL mysql.rds_set_external_source_gtid_purged('12345678-abcd-1234-efgh-123456789abc', 1, 100);

mysql.rds_set_master_auto_position

Sets the replication mode to be based on either binary log file positions or on global transaction identifiers (GTIDs).

Syntax

CALL mysql.rds_set_master_auto_position (
auto_position_mode
);

Parameters

Usage notes

The master user must run the mysql.rds_set_master_auto_position procedure.

This procedure is supported for all RDS for MySQL 5.7 versions, and RDS for MySQL 8.0.26 and higher 8.0 versions.

mysql.rds_set_source_delay

Sets the minimum number of seconds to delay replication from source database instance to the current read replica. Use this procedure when you are connected to a read replica to delay replication from its source database instance.

Syntax

CALL mysql.rds_set_source_delay(
delay
);

Parameters

Usage notes

The master user must run the mysql.rds_set_source_delay procedure.

For disaster recovery, you can use this procedure with the mysql.rds_start_replication_until stored procedure or the mysql.rds_start_replication_until_gtid stored procedure. To roll forward changes to a delayed read replica to the time just before a disaster, you can run the mysql.rds_set_source_delay procedure. After the mysql.rds_start_replication_until or mysql.rds_start_replication_until_gtid procedure stops replication, you can promote the read replica to be the new primary DB instance by using the instructions in Promoting a read replica to be a standalone DB instance.

To use the mysql.rds_rds_start_replication_until_gtid procedure, GTID-based replication must be enabled. To skip a specific GTID-based transaction that is known to cause disaster, you can use the mysql.rds_skip_transaction_with_gtid stored procedure. For more information on GTID-based replication, see Using GTID-based replication.

The mysql.rds_set_source_delay procedure is available in these versions of RDS for MySQL:

Examples

To delay replication from source database instance to the current read replica for at least one hour (3,600 seconds), you can call mysql.rds_set_source_delay with the following parameter:

CALL mysql.rds_set_source_delay(3600);

mysql.rds_skip_repl_error

Skips and deletes a replication error on a MySQL DB read replica.

Syntax

CALL mysql.rds_skip_repl_error;

Usage notes

The master user must run the mysql.rds_skip_repl_error procedure on a read replica. For more information about this procedure, see Calling the mysql.rds_skip_repl_error procedure.

To determine if there are errors, run the MySQL SHOW REPLICA STATUS\G command. If a replication error isn't critical, you can run mysql.rds_skip_repl_error to skip the error. If there are multiple errors, mysql.rds_skip_repl_error deletes the first error, then warns that others are present. You can then use SHOW REPLICA STATUS\G to determine the correct course of action for the next error. For information about the values returned, see SHOW REPLICA STATUS statement in the MySQL documentation.

For more information about addressing replication errors with Amazon RDS, see Troubleshooting a MySQL read replica problem.

Replication stopped error

When you call the mysql.rds_skip_repl_error procedure, you might receive an error message stating that the replica is down or disabled.

This error message appears if you run the procedure on the primary instance instead of the read replica. You must run this procedure on the read replica for the procedure to work.

This error message might also appear if you run the procedure on the read replica, but replication can't be restarted successfully.

If you need to skip a large number of errors, the replication lag can increase beyond the default retention period for binary log (binlog) files. In this case, you might encounter a fatal error due to binlog files being purged before they have been replayed on the read replica. This purge causes replication to stop, and you can no longer call the mysql.rds_skip_repl_error command to skip replication errors.

You can mitigate this issue by increasing the number of hours that binlog files are retained on your source database instance. After you have increased the binlog retention time, you can restart replication and call the mysql.rds_skip_repl_error command as needed.

To set the binlog retention time, use the mysql.rds_set_configuration procedure and specify a configuration parameter of 'binlog retention hours' along with the number of hours to retain binlog files on the DB cluster. The following example sets the retention period for binlog files to 48 hours.

CALL mysql.rds_set_configuration('binlog retention hours', 48);

mysql.rds_start_replication

Initiates replication from an RDS for MySQL DB instance.

Syntax

CALL mysql.rds_start_replication;

Usage notes

The master user must run the mysql.rds_start_replication procedure.

To import data from an instance of MySQL external to Amazon RDS, call mysql.rds_start_replication on the read replica to start the replication process after you call mysql.rds_set_external_master to build the replication configuration. For more information, see Restoring a backup into an Amazon RDS for MySQL DB instance.

To export data to an instance of MySQL external to Amazon RDS, call mysql.rds_start_replication and mysql.rds_stop_replication on the read replica to control some replication actions, such as purging binary logs. For more information, see Exporting data from a MySQL DB instance by using replication.

You can also call mysql.rds_start_replication on the read replica to restart any replication process that you previously stopped by calling mysql.rds_stop_replication. For more information, see Working with DB instance read replicas.

mysql.rds_start_replication_until

Initiates replication from an RDS for MySQL DB instance and stops replication at the specified binary log file location.

Syntax

CALL mysql.rds_start_replication_until (
replication_log_file
  , replication_stop_point
);

Parameters

Usage notes

The master user must run the mysql.rds_start_replication_until procedure.

The mysql.rds_start_replication_until procedure is available in these versions of RDS for MySQL:

You can use this procedure with delayed replication for disaster recovery. If you have delayed replication configured, you can use this procedure to roll forward changes to a delayed read replica to the time just before a disaster. After this procedure stops replication, you can promote the read replica to be the new primary DB instance by using the instructions in Promoting a read replica to be a standalone DB instance.

You can configure delayed replication using the following stored procedures:

The file name specified for the replication_log_file parameter must match the source database instance binlog file name.

When the replication_stop_point parameter specifies a stop location that is in the past, replication is stopped immediately.

Examples

The following example initiates replication and replicates changes until it reaches location 120 in the mysql-bin-changelog.000777 binary log file.

call mysql.rds_start_replication_until(
  'mysql-bin-changelog.000777',
  120);

mysql.rds_stop_replication

Stops replication from a MySQL DB instance.

Syntax

CALL mysql.rds_stop_replication;

Usage notes

The master user must run the mysql.rds_stop_replication procedure.

If you are configuring replication to import data from an instance of MySQL running external to Amazon RDS, you call mysql.rds_stop_replication on the read replica to stop the replication process after the import has completed. For more information, see Restoring a backup into an Amazon RDS for MySQL DB instance.

If you are configuring replication to export data to an instance of MySQL external to Amazon RDS, you call mysql.rds_start_replication and mysql.rds_stop_replication on the read replica to control some replication actions, such as purging binary logs. For more information, see Exporting data from a MySQL DB instance by using replication.

You can also use mysql.rds_stop_replication to stop replication between two Amazon RDS DB instances. You typically stop replication to perform a long running operation on the read replica, such as creating a large index on the read replica. You can restart any replication process that you stopped by calling mysql.rds_start_replication on the read replica. For more information, see Working with DB instance read replicas.