Replication and Binary Log Status Variables

The terms master and slave have historically been used in replication, but the terms terms primary and replica are now preferred. The old terms are used throughout the documentation, and in MariaDB commands, although MariaDB 10.5 has begun the process of renaming. The documentation will follow over time. See MDEV-18777 to follow progress on this effort.

The following status variables are useful in binary logging and replication. See Server Status Variables for a complete list of status variables that can be viewed with SHOW STATUS.

`Binlog_bytes_written`

Description: The number of bytes written to the binary log.
Scope: Global
Data Type: numeric

`Binlog_cache_disk_use`

Description: Number of transactions which used a temporary disk cache because they could not fit in the regular binary log cache, being larger than binlog_cache_size. The global value can be flushed by FLUSH STATUS.
Scope: Global
Data Type: numeric

`Binlog_cache_use`

Description: Number of transaction which used the regular binary log cache, being smaller than binlog_cache_size. The global value can be flushed by FLUSH STATUS.
Scope: Global
Data Type: numeric

`Binlog_commits`

Description: Total number of transactions committed to the binary log.
Scope: Global
Data Type: numeric

`Binlog_group_commit_trigger_count`

Description: Total number of group commits triggered because of the number of binary log commits in the group reached the limit set by the variable binlog_commit_wait_count. See Group commit for the binary log.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.1.5, MariaDB 10.0.18

`Binlog_group_commit_trigger_lock_wait`

Description: Total number of group commits triggered because a binary log commit was being delayed because of a lock wait where the lock was held by a prior binary log commit. When this happens the later binary log commit is placed in the next group commit. See Group commit for the binary log.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.1.5, MariaDB 10.0.18

`Binlog_group_commit_trigger_timeout`

Description: Total number of group commits triggered because of the time since the first binary log commit reached the limit set by the variable binlog_commit_wait_usec. See Group commit for the binary log.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.1.5, MariaDB 10.0.18

`Binlog_group_commits`

Description: Total number of group commits done to the binary log. See Group commit for the binary log.
Scope: Global
Data Type: numeric

`Binlog_snapshot_file`

Description: The binary log file. Unlike SHOW MASTER STATUS, can be queried in a transactionally consistent way, irrespective of which other transactions have been committed since the snapshot was taken. See Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT.
Scope: Global
Data Type: string

`Binlog_snapshot_position`

Description: The binary log position. Unlike SHOW MASTER STATUS, can be queried in a transactionally consistent way, irrespective of which other transactions have been committed since the snapshot was taken. See Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT.
Scope: Global
Data Type: numeric

`Binlog_stmt_cache_disk_use`

Description: Number of non-transaction statements which used a temporary disk cache because they could not fit in the regular binary log cache, being larger than binlog_stmt_cache_size. The global value can be flushed by FLUSH STATUS.
Scope: Global
Data Type: numeric

`Binlog_stmt_cache_use`

Description: Number of non-transaction statement which used the regular binary log cache, being smaller than binlog_stmt_cache_size. The global value can be flushed by FLUSH STATUS.
Scope: Global
Data Type: numeric

`Com_change_master`

Description: Number of CHANGE MASTER TO statements executed.
Scope: Global, Session
Data Type: numeric

`Com_show_binlog_status`

Description:
Scope: Global, Session
Data Type: numeric
Introduced: MariaDB 10.5.2

`Com_show_master_status`

Description: Number of SHOW MASTER STATUS commands executed.
Scope: Global, Session
Data Type: numeric
Removed: MariaDB 10.5.2

`Com_show_new_master`

Description:
Scope: Global, Session
Data Type: numeric
Removed: MariaDB 5.5

`Com_show_slave_hosts`

Description: Number of SHOW SLAVE HOSTS commands executed.
Scope: Global, Session
Data Type: numeric

`Com_show_slave_status`

Description: Number of SHOW SLAVE STATUS commands executed.
Scope: Global, Session
Data Type: numeric

`Com_slave_start`

Description: Number of START SLAVE commands executed. Removed in MariaDB 10.0, see Com_start_slave.
Scope: Global, Session
Data Type: numeric
Removed: MariaDB 10.0

`Com_slave_stop`

Description: Number of STOP SLAVE commands executed. Removed in MariaDB 10.0, see Com_stop_slave.
Scope: Global, Session
Data Type: numeric
Removed: MariaDB 10.0

`Com_start_all_slaves`

Description: Number of START ALL SLAVES commands executed.
Scope: Global, Session
Data Type: numeric
Introduced: MariaDB 10.0.0

`Com_start_slave`

Description: Number of START SLAVE commands executed. Replaces the old Com_slave_start.
Scope: Global, Session
Data Type: numeric
Introduced: MariaDB 10.0.0

`Com_stop_all_slaves`

Description: Number of STOP ALL SLAVES commands executed.
Scope: Global, Session
Data Type: numeric
Introduced: MariaDB 10.0.0

`Com_stop_slave`

Description: Number of STOP SLAVE commands executed. Replaces the old Com_slave_stop.
Scope: Global, Session
Data Type: numeric
Introduced: MariaDB 10.0.0

`Master_gtid_wait_count`

Description: Number of times MASTER_GTID_WAIT called.
Scope: Global, Session
Data Type: numeric
Introduced: MariaDB 10.1.4

`Master_gtid_wait_time`

Description: Total number of time spent in MASTER_GTID_WAIT.
Scope: Global, Session
Data Type: numeric
Introduced: MariaDB 10.1.4

`Master_gtid_wait_timeouts`

Description: Number of timeouts occurring in MASTER_GTID_WAIT.
Scope: Global, Session
Data Type: numeric
Introduced: MariaDB 10.1.4

`Rpl_status`

Description: For showing the status of fail-safe replication. Removed in MySQL 5.6, still present in MariaDB 10.0.

`Rpl_transactions_multi_engine`

Description: Number of replicated transactions that involved changes in multiple (transactional) storage engines, before considering the update of mysql.gtid_slave_pos. These are transactions that were already cross-engine, independent of the GTID position update introduced by replication. The global value can be flushed by FLUSH STATUS.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.3.1

`Slave_connections`

Description: Number of REGISTER_SLAVE attempts. In practice the number of times slaves has tried to connect to the master.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.1.11

`Slave_heartbeat_period`

Description: Time in seconds that a heartbeat packet is requested from the master by a slave.
Scope: Global
Data Type: numeric

`Slave_open_temp_tables`

Description: Number of temporary tables the slave has open.
Scope: Global
Data Type: numeric

`Slave_received_heartbeats`

Description: Number of heartbeats the slave has received from the master.
Scope: Global
Data Type: numeric

`Slave_retried_transactions`

Description: Number of times the slave has retried transactions since the server started. The global value can be flushed by FLUSH STATUS.
Scope: Global
Data Type: numeric

`Slave_running`

Description: Whether the slave is running (both I/O and SQL threads running) or not.
Scope: Global
Data Type: numeric

`Slave_skipped_errors`

Description: The number of times a slave has skipped errors defined by slave-skip-errors.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.0.18

`Slaves_connected`

Description: Number of slaves connected.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.1.11

`Slaves_running`

Description: Number of slave SQL threads running.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.1.11

`Transactions_gtid_foreign_engine`

Description: Number of replicated transactions where the update of the gtid_slave_pos table had to choose a storage engine that did not otherwise participate in the transaction. This can indicate that setting gtid_pos_auto_engines might be useful. The global value can be flushed by FLUSH STATUS.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.3.1

`Transactions_multi_engine`

Description: Number of transactions that changed data in multiple (transactional) storage engines. If this is significantly larger than Rpl_transactions_multi_engine, it indicates that setting gtid_pos_auto_engines could reduce the need for cross-engine transactions. The global value can be flushed by FLUSH STATUS.
Scope: Global
Data Type: numeric
Introduced: MariaDB 10.3.1

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https://mariadb.com/kb/en/replication-and-binary-log-status-variables/