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Replication and Binary Log Status Variables

View the status variables used to monitor replication health. Learn how to interpret metrics regarding log positions, connection status, and event counts.

The terms master and slave have historically been used in replication, and MariaDB has begun the process of adding primary and replica synonyms. The old terms will continue to be used to maintain backward compatibility - 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 .
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 cache, being larger than . The global value can be flushed by .
Scope: Global
Data Type: numeric

`Binlog_cache_use`

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

`Binlog_commits`

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

`Binlog_disk_use`

Description: If is not set to zero, shows the space usage of the binary log in bytes.
Scope: Global
Data Type: numeric
Introduced:

`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 . See .
Scope: Global
Data Type: numeric

`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 .
Scope: Global
Data Type: numeric

`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 . See .
Scope: Global
Data Type: numeric

`Binlog_group_commits`

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

`Binlog_gtid_index_hit`

Description: Incremented for each successful lookup in a .
Scope: Global
Data Type: numeric
Introduced:

`Binlog_gtid_index_miss`

Description: Incremented when a lookup is not possible, which indicates that the index file is missing (eg. binlog written by old server version without GTID index support), or corrupt.
Scope: Global
Data Type: numeric
Introduced:

`Binlog_snapshot_file`

Description: The binary log file. Unlike , can be queried in a transactionally consistent way, irrespective of which other transactions have been committed since the snapshot was taken. See .
Scope: Global
Data Type: string

`Binlog_snapshot_position`

Description: The binary log position. Unlike , can be queried in a transactionally consistent way, irrespective of which other transactions have been committed since the snapshot was taken. See .
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 cache, being larger than . The global value can be flushed by .
Scope: Global
Data Type: numeric

`Binlog_stmt_cache_use`

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

`Com_change_master`

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

`Com_show_binlog_status`

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

`Com_show_master_status`

Description: Number of commands executed.
Scope: Global, Session
Data Type: numeric
Removed:

`Com_show_new_master`

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

`Com_show_slave_hosts`

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

`Com_show_slave_status`

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

`Com_slave_start`

Description: Number of commands executed. Removed in , see .
Scope: Global, Session
Data Type: numeric
Removed:

`Com_slave_stop`

Description: Number of commands executed. Removed in , see .
Scope: Global, Session
Data Type: numeric
Removed:

`Com_start_all_slaves`

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

`Com_start_slave`

Description: Number of commands executed. Replaces the old .
Scope: Global, Session
Data Type: numeric

`Com_stop_all_slaves`

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

`Com_stop_slave`

Description: Number of commands executed. Replaces the old .
Scope: Global, Session
Data Type: numeric

`Master_gtid_wait_count`

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

`Master_gtid_wait_time`

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

`Master_gtid_wait_timeouts`

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

`Rpl_status`

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

`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 .
Scope: Global
Data Type: numeric

`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

`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 .
Scope: Global
Data Type: numeric

`Slave_running`

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

`Slave_skipped_errors`

Description: The number of times a slave has skipped errors defined by .
Scope: Global
Data Type: numeric

`Slaves_connected`

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

`Slaves_running`

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

`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 might be useful. The global value can be flushed by .
Scope: Global
Data Type: numeric

`Transactions_multi_engine`

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

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