Server Status Variables
The server maintains many status variables that provide information about its operation. You can view these variables and their values by using the SHOW [GLOBAL | SESSION] STATUS
statement (see , "SHOW STATUS
Syntax"). The optional GLOBAL
keyword aggregates the values over all connections, and SESSION
shows the values for the current connection.
mysql> SHOW GLOBAL STATUS;
+-----------------------------------+------------+
| Variable_name | Value |
+-----------------------------------+------------+
| Aborted_clients | 0 |
| Aborted_connects | 0 |
| Bytes_received | 155372598 |
| Bytes_sent | 1176560426 |
...
| Connections | 30023 |
| Created_tmp_disk_tables | 0 |
| Created_tmp_files | 3 |
| Created_tmp_tables | 2 |
...
| Threads_created | 217 |
| Threads_running | 88 |
| Uptime | 1389872 |
+-----------------------------------+------------+
Many status variables are reset to 0 by the FLUSH STATUS
statement.
The following table lists all available server status variables:
Table 5.4. Status Variable Summary
Variable Name | Variable Type | Variable Scope |
---|---|---|
Aborted_clients
| numeric | GLOBAL
|
Aborted_connects
| numeric | GLOBAL
|
Binlog_cache_disk_use
| numeric | GLOBAL
|
Binlog_cache_use
| numeric | GLOBAL
|
binlog_rows_query_log_events
| boolean | GLOBAL | SESSION
|
Binlog_stmt_cache_disk_use
| numeric | GLOBAL
|
Binlog_stmt_cache_use
| numeric | GLOBAL
|
Bytes_received
| numeric | GLOBAL | SESSION
|
Bytes_sent
| numeric | GLOBAL | SESSION
|
Com_admin_commands
| numeric | GLOBAL | SESSION
|
Com_alter_db
| numeric | GLOBAL | SESSION
|
Com_alter_db_upgrade
| numeric | GLOBAL | SESSION
|
Com_alter_event
| numeric | GLOBAL | SESSION
|
Com_alter_function
| numeric | GLOBAL | SESSION
|
Com_alter_procedure
| numeric | GLOBAL | SESSION
|
Com_alter_server
| numeric | GLOBAL | SESSION
|
Com_alter_table
| numeric | GLOBAL | SESSION
|
Com_alter_tablespace
| numeric | GLOBAL | SESSION
|
Com_analyze
| numeric | GLOBAL | SESSION
|
Com_assign_to_keycache
| numeric | GLOBAL | SESSION
|
Com_begin
| numeric | GLOBAL | SESSION
|
Com_binlog
| numeric | GLOBAL | SESSION
|
Com_call_procedure
| numeric | GLOBAL | SESSION
|
Com_change_db
| numeric | GLOBAL | SESSION
|
Com_change_master
| numeric | GLOBAL | SESSION
|
Com_check
| numeric | GLOBAL | SESSION
|
Com_checksum
| numeric | GLOBAL | SESSION
|
Com_commit
| numeric | GLOBAL | SESSION
|
Com_create_db
| numeric | GLOBAL | SESSION
|
Com_create_event
| numeric | GLOBAL | SESSION
|
Com_create_function
| numeric | GLOBAL | SESSION
|
Com_create_index
| numeric | GLOBAL | SESSION
|
Com_create_procedure
| numeric | GLOBAL | SESSION
|
Com_create_server
| numeric | GLOBAL | SESSION
|
Com_create_table
| numeric | GLOBAL | SESSION
|
Com_create_trigger
| numeric | GLOBAL | SESSION
|
Com_create_udf
| numeric | GLOBAL | SESSION
|
Com_create_user
| numeric | GLOBAL | SESSION
|
Com_create_view
| numeric | GLOBAL | SESSION
|
Com_dealloc_sql
| numeric | GLOBAL | SESSION
|
Com_delete
| numeric | GLOBAL | SESSION
|
Com_delete_multi
| numeric | GLOBAL | SESSION
|
Com_do
| numeric | GLOBAL | SESSION
|
Com_drop_db
| numeric | GLOBAL | SESSION
|
Com_drop_event
| numeric | GLOBAL | SESSION
|
Com_drop_function
| numeric | GLOBAL | SESSION
|
Com_drop_index
| numeric | GLOBAL | SESSION
|
Com_drop_procedure
| numeric | GLOBAL | SESSION
|
Com_drop_server
| numeric | GLOBAL | SESSION
|
Com_drop_table
| numeric | GLOBAL | SESSION
|
Com_drop_trigger
| numeric | GLOBAL | SESSION
|
Com_drop_user
| numeric | GLOBAL | SESSION
|
Com_drop_view
| numeric | GLOBAL | SESSION
|
Com_empty_query
| numeric | GLOBAL | SESSION
|
Com_execute_sql
| numeric | GLOBAL | SESSION
|
Com_flush
| numeric | GLOBAL | SESSION
|
Com_grant
| numeric | GLOBAL | SESSION
|
Com_ha_close
| numeric | GLOBAL | SESSION
|
Com_ha_open
| numeric | GLOBAL | SESSION
|
Com_ha_read
| numeric | GLOBAL | SESSION
|
Com_help
| numeric | GLOBAL | SESSION
|
Com_insert
| numeric | GLOBAL | SESSION
|
Com_insert_select
| numeric | GLOBAL | SESSION
|
Com_install_plugin
| numeric | GLOBAL | SESSION
|
Com_kill
| numeric | GLOBAL | SESSION
|
Com_load
| numeric | GLOBAL | SESSION
|
Com_lock_tables
| numeric | GLOBAL | SESSION
|
Com_optimize
| numeric | GLOBAL | SESSION
|
Com_preload_keys
| numeric | GLOBAL | SESSION
|
Com_prepare_sql
| numeric | GLOBAL | SESSION
|
Com_purge
| numeric | GLOBAL | SESSION
|
Com_purge_before_date
| numeric | GLOBAL | SESSION
|
Com_release_savepoint
| numeric | GLOBAL | SESSION
|
Com_rename_table
| numeric | GLOBAL | SESSION
|
Com_rename_user
| numeric | GLOBAL | SESSION
|
Com_repair
| numeric | GLOBAL | SESSION
|
Com_replace
| numeric | GLOBAL | SESSION
|
Com_replace_select
| numeric | GLOBAL | SESSION
|
Com_reset
| numeric | GLOBAL | SESSION
|
Com_resignal
| numeric | GLOBAL | SESSION
|
Com_revoke
| numeric | GLOBAL | SESSION
|
Com_revoke_all
| numeric | GLOBAL | SESSION
|
Com_rollback
| numeric | GLOBAL | SESSION
|
Com_rollback_to_savepoint
| numeric | GLOBAL | SESSION
|
Com_savepoint
| numeric | GLOBAL | SESSION
|
Com_select
| numeric | GLOBAL | SESSION
|
Com_set_option
| numeric | GLOBAL | SESSION
|
Com_show_authors
| numeric | GLOBAL | SESSION
|
Com_show_binlog_events
| numeric | GLOBAL | SESSION
|
Com_show_binlogs
| numeric | GLOBAL | SESSION
|
Com_show_charsets
| numeric | GLOBAL | SESSION
|
Com_show_collations
| numeric | GLOBAL | SESSION
|
Com_show_contributors
| numeric | GLOBAL | SESSION
|
Com_show_create_db
| numeric | GLOBAL | SESSION
|
Com_show_create_event
| numeric | GLOBAL | SESSION
|
Com_show_create_func
| numeric | GLOBAL | SESSION
|
Com_show_create_proc
| numeric | GLOBAL | SESSION
|
Com_show_create_table
| numeric | GLOBAL | SESSION
|
Com_show_create_trigger
| numeric | GLOBAL | SESSION
|
Com_show_databases
| numeric | GLOBAL | SESSION
|
Com_show_engine_logs
| numeric | GLOBAL | SESSION
|
Com_show_engine_mutex
| numeric | GLOBAL | SESSION
|
Com_show_engine_status
| numeric | GLOBAL | SESSION
|
Com_show_errors
| numeric | GLOBAL | SESSION
|
Com_show_events
| numeric | GLOBAL | SESSION
|
Com_show_fields
| numeric | GLOBAL | SESSION
|
Com_show_function_code
| numeric | GLOBAL | SESSION
|
Com_show_function_status
| numeric | GLOBAL | SESSION
|
Com_show_grants
| numeric | GLOBAL | SESSION
|
Com_show_keys
| numeric | GLOBAL | SESSION
|
Com_show_logs
| numeric | GLOBAL | SESSION
|
Com_show_master_status
| numeric | GLOBAL | SESSION
|
Com_show_new_master
| numeric | GLOBAL | SESSION
|
Com_show_open_tables
| numeric | GLOBAL | SESSION
|
Com_show_plugins
| numeric | GLOBAL | SESSION
|
Com_show_privileges
| numeric | GLOBAL | SESSION
|
Com_show_procedure_code
| numeric | GLOBAL | SESSION
|
Com_show_procedure_status
| numeric | GLOBAL | SESSION
|
Com_show_processlist
| numeric | GLOBAL | SESSION
|
Com_show_profile
| numeric | GLOBAL | SESSION
|
Com_show_profiles
| numeric | GLOBAL | SESSION
|
Com_show_relaylog_events
| numeric | GLOBAL | SESSION
|
Com_show_slave_hosts
| numeric | GLOBAL | SESSION
|
Com_show_slave_status
| numeric | GLOBAL | SESSION
|
Com_show_status
| numeric | GLOBAL | SESSION
|
Com_show_storage_engines
| numeric | GLOBAL | SESSION
|
Com_show_table_status
| numeric | GLOBAL | SESSION
|
Com_show_tables
| numeric | GLOBAL | SESSION
|
Com_show_triggers
| numeric | GLOBAL | SESSION
|
Com_show_variables
| numeric | GLOBAL | SESSION
|
Com_show_warnings
| numeric | GLOBAL | SESSION
|
Com_signal
| numeric | GLOBAL | SESSION
|
Com_slave_start
| numeric | GLOBAL | SESSION
|
Com_slave_stop
| numeric | GLOBAL | SESSION
|
Com_stmt_close
| numeric | GLOBAL | SESSION
|
Com_stmt_execute
| numeric | GLOBAL | SESSION
|
Com_stmt_fetch
| numeric | GLOBAL | SESSION
|
Com_stmt_prepare
| numeric | GLOBAL | SESSION
|
Com_stmt_reprepare
| numeric | GLOBAL | SESSION
|
Com_stmt_reset
| numeric | GLOBAL | SESSION
|
Com_stmt_send_long_data
| numeric | GLOBAL | SESSION
|
Com_truncate
| numeric | GLOBAL | SESSION
|
Com_uninstall_plugin
| numeric | GLOBAL | SESSION
|
Com_unlock_tables
| numeric | GLOBAL | SESSION
|
Com_update
| numeric | GLOBAL | SESSION
|
Com_update_multi
| numeric | GLOBAL | SESSION
|
Com_xa_commit
| numeric | GLOBAL | SESSION
|
Com_xa_end
| numeric | GLOBAL | SESSION
|
Com_xa_prepare
| numeric | GLOBAL | SESSION
|
Com_xa_recover
| numeric | GLOBAL | SESSION
|
Com_xa_rollback
| numeric | GLOBAL | SESSION
|
Com_xa_start
| numeric | GLOBAL | SESSION
|
Compression
| numeric | SESSION
|
Connection_errors_accept
| numeric | GLOBAL
|
Connection_errors_internal
| numeric | GLOBAL
|
Connection_errors_max_connections
| numeric | GLOBAL
|
Connection_errors_peer_addr
| numeric | GLOBAL
|
Connection_errors_select
| numeric | GLOBAL
|
Connection_errors_tcpwrap
| numeric | GLOBAL
|
Connections
| numeric | GLOBAL
|
Created_tmp_disk_tables
| numeric | GLOBAL | SESSION
|
Created_tmp_files
| numeric | GLOBAL
|
Created_tmp_tables
| numeric | GLOBAL | SESSION
|
Delayed_errors
| numeric | GLOBAL
|
Delayed_insert_threads
| numeric | GLOBAL
|
Delayed_writes
| numeric | GLOBAL
|
Flush_commands
| numeric | GLOBAL
|
Handler_commit
| numeric | GLOBAL | SESSION
|
Handler_delete
| numeric | GLOBAL | SESSION
|
Handler_discover
| numeric | GLOBAL | SESSION
|
Handler_external_lock
| numeric | GLOBAL | SESSION
|
Handler_prepare
| numeric | GLOBAL | SESSION
|
Handler_read_first
| numeric | GLOBAL | SESSION
|
Handler_read_key
| numeric | GLOBAL | SESSION
|
Handler_read_last
| numeric | GLOBAL | SESSION
|
Handler_read_next
| numeric | GLOBAL | SESSION
|
Handler_read_prev
| numeric | GLOBAL | SESSION
|
Handler_read_rnd
| numeric | GLOBAL | SESSION
|
Handler_read_rnd_next
| numeric | GLOBAL | SESSION
|
Handler_rollback
| numeric | GLOBAL | SESSION
|
Handler_savepoint
| numeric | GLOBAL | SESSION
|
Handler_savepoint_rollback
| numeric | GLOBAL | SESSION
|
Handler_update
| numeric | GLOBAL | SESSION
|
Handler_write
| numeric | GLOBAL | SESSION
|
Innodb_buffer_pool_dump_status
| numeric | GLOBAL
|
Innodb_buffer_pool_load_status
| numeric | GLOBAL
|
Innodb_buffer_pool_pages_data
| numeric | GLOBAL
|
Innodb_buffer_pool_pages_dirty
| numeric | GLOBAL
|
Innodb_buffer_pool_pages_flushed
| numeric | GLOBAL
|
Innodb_buffer_pool_pages_free
| numeric | GLOBAL
|
Innodb_buffer_pool_pages_latched
| numeric | GLOBAL
|
Innodb_buffer_pool_pages_misc
| numeric | GLOBAL
|
Innodb_buffer_pool_pages_total
| numeric | GLOBAL
|
Innodb_buffer_pool_read_ahead
| numeric | GLOBAL
|
Innodb_buffer_pool_read_ahead_evicted
| numeric | GLOBAL
|
Innodb_buffer_pool_read_requests
| numeric | GLOBAL
|
Innodb_buffer_pool_reads
| numeric | GLOBAL
|
Innodb_buffer_pool_wait_free
| numeric | GLOBAL
|
Innodb_buffer_pool_write_requests
| numeric | GLOBAL
|
Innodb_data_fsyncs
| numeric | GLOBAL
|
Innodb_data_pending_fsyncs
| numeric | GLOBAL
|
Innodb_data_pending_reads
| numeric | GLOBAL
|
Innodb_data_pending_writes
| numeric | GLOBAL
|
Innodb_data_read
| numeric | GLOBAL
|
Innodb_data_reads
| numeric | GLOBAL
|
Innodb_data_writes
| numeric | GLOBAL
|
Innodb_data_written
| numeric | GLOBAL
|
Innodb_dblwr_pages_written
| numeric | GLOBAL
|
Innodb_dblwr_writes
| numeric | GLOBAL
|
Innodb_have_atomic_builtins
| numeric | GLOBAL
|
Innodb_log_waits
| numeric | GLOBAL
|
Innodb_log_write_requests
| numeric | GLOBAL
|
Innodb_log_writes
| numeric | GLOBAL
|
Innodb_num_open_files
| numeric | GLOBAL
|
Innodb_os_log_fsyncs
| numeric | GLOBAL
|
Innodb_os_log_pending_fsyncs
| numeric | GLOBAL
|
Innodb_os_log_pending_writes
| numeric | GLOBAL
|
Innodb_os_log_written
| numeric | GLOBAL
|
Innodb_page_size
| numeric | GLOBAL
|
Innodb_pages_created
| numeric | GLOBAL
|
Innodb_pages_read
| numeric | GLOBAL
|
Innodb_pages_written
| numeric | GLOBAL
|
Innodb_row_lock_current_waits
| numeric | GLOBAL
|
Innodb_row_lock_time
| numeric | GLOBAL
|
Innodb_row_lock_time_avg
| numeric | GLOBAL
|
Innodb_row_lock_time_max
| numeric | GLOBAL
|
Innodb_row_lock_waits
| numeric | GLOBAL
|
Innodb_rows_deleted
| numeric | GLOBAL
|
Innodb_rows_inserted
| numeric | GLOBAL
|
Innodb_rows_read
| numeric | GLOBAL
|
Innodb_rows_updated
| numeric | GLOBAL
|
Innodb_truncated_status_writes
| numeric | GLOBAL
|
Key_blocks_not_flushed
| numeric | GLOBAL
|
Key_blocks_unused
| numeric | GLOBAL
|
Key_blocks_used
| numeric | GLOBAL
|
Key_read_requests
| numeric | GLOBAL
|
Key_reads
| numeric | GLOBAL
|
Key_write_requests
| numeric | GLOBAL
|
Key_writes
| numeric | GLOBAL
|
Last_query_cost
| numeric | SESSION
|
Last_query_partial_plans
| numeric | SESSION
|
Max_used_connections
| numeric | GLOBAL
|
Ndb_conflict_fn_max
| numeric | GLOBAL
|
Ndb_conflict_fn_old
| numeric | GLOBAL
|
Ndb_number_of_data_nodes
| numeric | GLOBAL
|
Not_flushed_delayed_rows
| numeric | GLOBAL
|
Open_files
| numeric | GLOBAL
|
Open_streams
| numeric | GLOBAL
|
Open_table_definitions
| numeric | GLOBAL
|
Open_tables
| numeric | GLOBAL | SESSION
|
Opened_files
| numeric | GLOBAL
|
Opened_table_definitions
| numeric | GLOBAL | SESSION
|
Opened_tables
| numeric | GLOBAL | SESSION
|
Performance_schema_accounts_lost
| numeric | GLOBAL
|
Performance_schema_cond_classes_lost
| numeric | GLOBAL
|
Performance_schema_cond_instances_lost
| numeric | GLOBAL
|
Performance_schema_file_classes_lost
| numeric | GLOBAL
|
Performance_schema_file_handles_lost
| numeric | GLOBAL
|
Performance_schema_file_instances_lost
| numeric | GLOBAL
|
Performance_schema_hosts_lost
| numeric | GLOBAL
|
Performance_schema_locker_lost
| numeric | GLOBAL
|
Performance_schema_mutex_classes_lost
| numeric | GLOBAL
|
Performance_schema_mutex_instances_lost
| numeric | GLOBAL
|
Performance_schema_rwlock_classes_lost
| numeric | GLOBAL
|
Performance_schema_rwlock_instances_lost
| numeric | GLOBAL
|
Performance_schema_socket_classes_lost
| numeric | GLOBAL
|
Performance_schema_socket_instances_lost
| numeric | GLOBAL
|
Performance_schema_stage_classes_lost
| numeric | GLOBAL
|
Performance_schema_statement_classes_lost
| numeric | GLOBAL
|
Performance_schema_table_handles_lost
| numeric | GLOBAL
|
Performance_schema_table_instances_lost
| numeric | GLOBAL
|
Performance_schema_thread_classes_lost
| numeric | GLOBAL
|
Performance_schema_thread_instances_lost
| numeric | GLOBAL
|
Performance_schema_users_lost
| numeric | GLOBAL
|
Prepared_stmt_count
| numeric | GLOBAL
|
Qcache_free_blocks
| numeric | GLOBAL
|
Qcache_free_memory
| numeric | GLOBAL
|
Qcache_hits
| numeric | GLOBAL
|
Qcache_inserts
| numeric | GLOBAL
|
Qcache_lowmem_prunes
| numeric | GLOBAL
|
Qcache_not_cached
| numeric | GLOBAL
|
Qcache_queries_in_cache
| numeric | GLOBAL
|
Qcache_total_blocks
| numeric | GLOBAL
|
Queries
| numeric | GLOBAL | SESSION
|
Questions
| numeric | GLOBAL | SESSION
|
Rpl_semi_sync_master_clients
| numeric | GLOBAL
|
Rpl_semi_sync_master_net_avg_wait_time
| numeric | GLOBAL
|
Rpl_semi_sync_master_net_wait_time
| numeric | GLOBAL
|
Rpl_semi_sync_master_net_waits
| numeric | GLOBAL
|
Rpl_semi_sync_master_no_times
| numeric | GLOBAL
|
Rpl_semi_sync_master_no_tx
| numeric | GLOBAL
|
Rpl_semi_sync_master_status
| boolean | GLOBAL
|
Rpl_semi_sync_master_timefunc_failures
| numeric | GLOBAL
|
Rpl_semi_sync_master_tx_avg_wait_time
| numeric | GLOBAL
|
Rpl_semi_sync_master_tx_wait_time
| numeric | GLOBAL
|
Rpl_semi_sync_master_tx_waits
| numeric | GLOBAL
|
Rpl_semi_sync_master_wait_pos_backtraverse
| numeric | GLOBAL
|
Rpl_semi_sync_master_wait_sessions
| numeric | GLOBAL
|
Rpl_semi_sync_master_yes_tx
| numeric | GLOBAL
|
Rpl_semi_sync_slave_status
| boolean | GLOBAL
|
Select_full_join
| numeric | GLOBAL | SESSION
|
Select_full_range_join
| numeric | GLOBAL | SESSION
|
Select_range
| numeric | GLOBAL | SESSION
|
Select_range_check
| numeric | GLOBAL | SESSION
|
Select_scan
| numeric | GLOBAL | SESSION
|
Slave_heartbeat_period
| GLOBAL
| |
Slave_last_heartbeat
| GLOBAL
| |
Slave_open_temp_tables
| numeric | GLOBAL
|
Slave_received_heartbeats
| GLOBAL
| |
Slave_retried_transactions
| numeric | GLOBAL
|
Slave_running
| boolean | GLOBAL
|
Slow_launch_threads
| numeric | GLOBAL | SESSION
|
Slow_queries
| numeric | GLOBAL | SESSION
|
Sort_merge_passes
| numeric | GLOBAL | SESSION
|
Sort_range
| numeric | GLOBAL | SESSION
|
Sort_rows
| numeric | GLOBAL | SESSION
|
Sort_scan
| numeric | GLOBAL | SESSION
|
Ssl_accept_renegotiates
| numeric | GLOBAL
|
Ssl_accepts
| numeric | GLOBAL
|
Ssl_callback_cache_hits
| numeric | GLOBAL
|
Ssl_cipher
| string | GLOBAL | SESSION
|
Ssl_cipher_list
| string | GLOBAL | SESSION
|
Ssl_client_connects
| numeric | GLOBAL
|
Ssl_connect_renegotiates
| numeric | GLOBAL
|
Ssl_ctx_verify_depth
| numeric | GLOBAL
|
Ssl_ctx_verify_mode
| numeric | GLOBAL
|
Ssl_default_timeout
| numeric | GLOBAL | SESSION
|
Ssl_finished_accepts
| numeric | GLOBAL
|
Ssl_finished_connects
| numeric | GLOBAL
|
Ssl_server_not_after
| numeric | GLOBAL | SESSION
|
Ssl_server_not_before
| numeric | GLOBAL | SESSION
|
Ssl_session_cache_hits
| numeric | GLOBAL
|
Ssl_session_cache_misses
| numeric | GLOBAL
|
Ssl_session_cache_mode
| string | GLOBAL
|
Ssl_session_cache_overflows
| numeric | GLOBAL
|
Ssl_session_cache_size
| numeric | GLOBAL
|
Ssl_session_cache_timeouts
| numeric | GLOBAL
|
Ssl_sessions_reused
| numeric | GLOBAL | SESSION
|
Ssl_used_session_cache_entries
| numeric | GLOBAL
|
Ssl_verify_depth
| numeric | GLOBAL | SESSION
|
Ssl_verify_mode
| numeric | GLOBAL | SESSION
|
Ssl_version
| string | GLOBAL | SESSION
|
Table_locks_immediate
| numeric | GLOBAL
|
Table_locks_waited
| numeric | GLOBAL
|
Tc_log_max_pages_used
| numeric | GLOBAL
|
Tc_log_page_size
| numeric | GLOBAL
|
Tc_log_page_waits
| numeric | GLOBAL
|
Threads_cached
| numeric | GLOBAL
|
Threads_connected
| numeric | GLOBAL
|
Threads_created
| numeric | GLOBAL
|
Threads_running
| numeric | GLOBAL
|
Uptime
| numeric | GLOBAL
|
Uptime_since_flush_status
| numeric | GLOBAL |
The status variables have the following meanings.
Aborted_clients
The number of connections that were aborted because the client died without closing the connection properly. See "Communication Errors and Aborted Connections".
Aborted_connects
The number of failed attempts to connect to the MariaDB server. See "Communication Errors and Aborted Connections".
For additional connection-related information, check the
Connection_errors_
status variables and thexxx
host_cache
table.Binlog_cache_disk_use
The number of transactions that used the temporary binary log cache but that exceeded the value of
binlog_cache_size
and used a temporary file to store statements from the transaction.The number of nontransactional statements that caused the binary log transaction cache to be written to disk is tracked separately in the
Binlog_stmt_cache_disk_use
status variable.Binlog_cache_use
The number of transactions that used the binary log cache.
Binlog_stmt_cache_disk_use
The number of nontransaction statements that used the binary log statement cache but that exceeded the value of
binlog_stmt_cache_size
and used a temporary file to store those statements.Binlog_stmt_cache_use
The number of nontransactional statements that used the binary log statement cache.
Bytes_received
The number of bytes received from all clients.
Bytes_sent
The number of bytes sent to all clients.
Com_
xxx
The
Com_
statement counter variables indicate the number of times eachxxx
xxx
statement has been executed. There is one status variable for each type of statement. For example,Com_delete
andCom_insert
countDELETE
andINSERT
statements, respectively. However, if a query result is returned from query cache, the server increments theQcache_hits
status variable, notCom_select
. See , "Query Cache Status and Maintenance".All of the
Com_stmt_
variables are increased even if a prepared statement argument is unknown or an error occurred during execution. In other words, their values correspond to the number of requests issued, not to the number of requests successfully completed.xxx
The
Com_stmt_
status variables are as follows:xxx
Com_stmt_prepare
Com_stmt_execute
Com_stmt_fetch
Com_stmt_send_long_data
Com_stmt_reset
Com_stmt_close
Those variables stand for prepared statement commands. Their names refer to the
COM_
command set used in the network layer. In other words, their values increase whenever prepared statement API calls such as mysql_stmt_prepare(), mysql_stmt_execute(), and so forth are executed. However,xxx
Com_stmt_prepare
,Com_stmt_execute
andCom_stmt_close
also increase forPREPARE
,EXECUTE
, orDEALLOCATE PREPARE
, respectively. Additionally, the values of the older statement counter variablesCom_prepare_sql
,Com_execute_sql
, andCom_dealloc_sql
increase for thePREPARE
,EXECUTE
, andDEALLOCATE PREPARE
statements.Com_stmt_fetch
stands for the total number of network round-trips issued when fetching from cursors.Com_stmt_reprepare
indicated the number of times statements were automatically reprepared by the server after metadata changes to tables or views referred to by the statement. A reprepare operation incrementsCom_stmt_reprepare
, and alsoCom_stmt_prepare
.Compression
Whether the client connection uses compression in the client/server protocol.
Connection_errors_
xxx
These variables provide information about errors that occur during the client connection process. They are global only and represent error counts aggregated across connections from all hosts. These variables track errors not accounted for by the host cache (see , "DNS Lookup Optimization and the Host Cache"), such as errors that are not associated with TCP connections, occur very early in the connection process (even before an IP address is known), or are not specific to any particular IP address (such as out-of-memory conditions). These variables were added in MariaDB 5.6.5.
Connection_errors_accept
The number of errors that occurred during calls to
accept()
on the listening port.Connection_errors_internal
The number of connections refused due to internal errors in the server, such as failure to start a new thread or an out-of-memory condition.
Connection_errors_max_connections
The number of connections refused because the server
max_connections
limit was reached.Connection_errors_peer_addr
The number of errors that occurred while searching for connecting client IP addresses.
Connection_errors_select
The number of errors that occurred during calls to
select()
orpoll()
on the listening port. (Failure of this operation does not necessarily means a client connection was rejected.)Connection_errors_tcpwrap
The number of connections refused by the
libwrap
library.
Connections
The number of connection attempts (successful or not) to the MariaDB server.
Created_tmp_disk_tables
The number of internal on-disk temporary tables created by the server while executing statements.
If an internal temporary table is created initially as an in-memory table but becomes too large, MariaDB automatically converts it to an on-disk table. The maximum size for in-memory temporary tables is the minimum of the
tmp_table_size
andmax_heap_table_size
values. IfCreated_tmp_disk_tables
is large, you may want to increase thetmp_table_size
ormax_heap_table_size
values. value to lessen the likelihood that internal temporary tables in memory will be converted to on-disk tables.You can compare the number of internal on-disk temporary tables created to the total number of internal temporary tables created by comparing the values of the
Created_tmp_disk_tables
andCreated_tmp_tables
variables.Created_tmp_files
How many temporary files mysqld has created.
Created_tmp_tables
The number of internal temporary tables created by the server while executing statements.
You can compare the number of internal on-disk temporary tables created to the total number of internal temporary tables created by comparing the values of the
Created_tmp_disk_tables
andCreated_tmp_tables
variables.See also , "How MariaDB Uses Internal Temporary Tables".
Each invocation of the
SHOW STATUS
statement uses an internal temporary table and increments the globalCreated_tmp_tables
value.Delayed_errors
The number of rows written with
INSERT DELAYED
for which some error occurred (probablyduplicate key
).Delayed_insert_threads
The number of
INSERT DELAYED
handler threads in use for nontransactional tables.Delayed_writes
The number of
INSERT DELAYED
rows written to nontransactional tables.Flush_commands
The number of times the server flushes tables, whether because a user executed a
FLUSH TABLES
statement or due to internal server operation. It is also incremented by receipt of aCOM_REFRESH
packet. This is in contrast toCom_flush
, which indicates how manyFLUSH
statements have been executed, whetherFLUSH TABLES
,FLUSH LOGS
, and so forth.Handler_commit
The number of internal
COMMIT
statements.Handler_delete
The number of times that rows have been deleted from tables.
Handler_external_lock
The number of locks started while a statement executed.
Handler_prepare
A counter for the prepare phase of two-phase commit operations.
Handler_read_first
The number of times the first entry in an index was read. If this value is high, it suggests that the server is doing a lot of full index scans; for example,
SELECT col1 FROM foo
, assuming thatcol1
is indexed.Handler_read_key
The number of requests to read a row based on a key. If this value is high, it is a good indication that your tables are properly indexed for your queries.
Handler_read_last
The number of requests to read the last key in an index. With
ORDER BY
, the server will issue a first-key request followed by several next-key requests, whereas with WithORDER BY DESC
, the server will issue a last-key request followed by several previous-key requests. This variable was added in MariaDB 5.6.1.Handler_read_next
The number of requests to read the next row in key order. This value is incremented if you are querying an index column with a range constraint or if you are doing an index scan.
Handler_read_prev
The number of requests to read the previous row in key order. This read method is mainly used to optimize
ORDER BY ... DESC
.Handler_read_rnd
The number of requests to read a row based on a fixed position. This value is high if you are doing a lot of queries that require sorting of the result. You probably have a lot of queries that require MariaDB to scan entire tables or you have joins that do not use keys properly.
Handler_read_rnd_next
The number of requests to read the next row in the data file. This value is high if you are doing a lot of table scans. Generally this suggests that your tables are not properly indexed or that your queries are not written to take advantage of the indexes you have.
Handler_rollback
The number of requests for a storage engine to perform a rollback operation.
Handler_savepoint
The number of requests for a storage engine to place a savepoint.
Handler_savepoint_rollback
The number of requests for a storage engine to roll back to a savepoint.
Handler_update
The number of requests to update a row in a table.
Handler_write
The number of requests to insert a row in a table.
Innodb_buffer_pool_dump_status
The progress of an operation to record the pages held in the InnoDB buffer pool, triggered by the setting of
innodb_buffer_pool_dump_at_shutdown
orinnodb_buffer_pool_dump_now
.Innodb_buffer_pool_load_status
The progress of an operation to 'warm up' the InnoDB buffer pool by reading in a set of pages corresponding to an earlier point in time, triggered by the setting of
innodb_buffer_pool_load_at_startup
orinnodb_buffer_pool_load_now
. If the operation introduces too much overhead, you can cancel it by settinginnodb_buffer_pool_load_abort
.Innodb_buffer_pool_pages_data
The number of pages containing data (dirty or clean).
Innodb_buffer_pool_pages_dirty
The number of pages currently dirty.
Innodb_buffer_pool_pages_flushed
The number of buffer pool page-flush requests.
Innodb_buffer_pool_pages_free
The number of free pages.
Innodb_buffer_pool_pages_latched
The number of latched pages in
InnoDB
buffer pool. These are pages currently being read or written or that cannot be flushed or removed for some other reason. Calculation of this variable is expensive, so it is available only when theUNIV_DEBUG
system is defined at server build time.Innodb_buffer_pool_pages_misc
The number of pages that are busy because they have been allocated for administrative overhead such as row locks or the adaptive hash index. This value can also be calculated as
Innodb_buffer_pool_pages_total
-Innodb_buffer_pool_pages_free
-Innodb_buffer_pool_pages_data
.Innodb_buffer_pool_pages_total
The total size of the buffer pool, in pages.
Innodb_buffer_pool_read_ahead
The number of pages read into the
InnoDB
buffer pool by the read-ahead background thread.Innodb_buffer_pool_read_ahead_evicted
The number of pages read into the
InnoDB
buffer pool by the read-ahead background thread that were subsequently evicted without having been accessed by queries.Innodb_buffer_pool_read_requests
The number of logical read requests
InnoDB
has done.Innodb_buffer_pool_reads
The number of logical reads that
InnoDB
could not satisfy from the buffer pool, and had to read directly from the disk.Innodb_buffer_pool_wait_free
Normally, writes to the
InnoDB
buffer pool happen in the background. However, if it is necessary to read or create a page and no clean pages are available, it is also necessary to wait for pages to be flushed first. This counter counts instances of these waits. If the buffer pool size has been set properly, this value should be small.Innodb_buffer_pool_write_requests
The number writes done to the
InnoDB
buffer pool.Innodb_data_fsyncs
The number of
fsync()
operations so far.Innodb_data_pending_fsyncs
The current number of pending
fsync()
operations.Innodb_data_pending_reads
The current number of pending reads.
Innodb_data_pending_writes
The current number of pending writes.
Innodb_data_read
The amount of data read since the server was started.
Innodb_data_reads
The total number of data reads.
Innodb_data_writes
The total number of data writes.
Innodb_data_written
The amount of data written so far, in bytes.
Innodb_dblwr_pages_written
The number of pages that have been written for doublewrite operations. See , "
InnoDB
Disk I/O".Innodb_dblwr_writes
The number of doublewrite operations that have been performed. See , "
InnoDB
Disk I/O".Innodb_have_atomic_builtins
Indicates whether the server was built with atomic instructions.
Innodb_log_waits
The number of times that the log buffer was too small and a wait was required for it to be flushed before continuing.
Innodb_log_write_requests
The number of log write requests.
Innodb_log_writes
The number of physical writes to the log file.
Innodb_num_open_files
The number of files
InnoDB
currently holds open.Innodb_os_log_fsyncs
The number of
fsync()
writes done to the log file.Innodb_os_log_pending_fsyncs
The number of pending log file
fsync()
operations.Innodb_os_log_pending_writes
The number of pending log file writes.
Innodb_os_log_written
The number of bytes written to the log file.
Innodb_page_size
The compiled-in
InnoDB
page size (default 16KB). Many values are counted in pages; the page size enables them to be easily converted to bytes.Innodb_pages_created
The number of pages created.
Innodb_pages_read
The number of pages read.
Innodb_pages_written
The number of pages written.
Innodb_row_lock_current_waits
The number of row locks currently being waited for.
Innodb_row_lock_time
The total time spent in acquiring row locks, in milliseconds.
Innodb_row_lock_time_avg
The average time to acquire a row lock, in milliseconds.
Innodb_row_lock_time_max
The maximum time to acquire a row lock, in milliseconds.
Innodb_row_lock_waits
The number of times a row lock had to be waited for.
Innodb_rows_deleted
The number of rows deleted from
InnoDB
tables.Innodb_rows_inserted
The number of rows inserted into
InnoDB
tables.Innodb_rows_read
The number of rows read from
InnoDB
tables.Innodb_rows_updated
The number of rows updated in
InnoDB
tables.Innodb_truncated_status_writes
The number of times output from the
SHOW ENGINE INNODB STATUS
statement has been truncated.Key_blocks_not_flushed
The number of key blocks in the key cache that have changed but have not yet been flushed to disk.
Key_blocks_unused
The number of unused blocks in the key cache. You can use this value to determine how much of the key cache is in use; see the discussion of
key_buffer_size
in , "Server System Variables".Key_blocks_used
The number of used blocks in the key cache. This value is a high-water mark that indicates the maximum number of blocks that have ever been in use at one time.
Key_read_requests
The number of requests to read a key block from the cache.
Key_reads
The number of physical reads of a key block from disk. If
Key-reads
is large, then yourkey_buffer_size
value is probably too small. The cache miss rate can be calculated asKey_reads
/Key_read_requests
.Key_write_requests
The number of requests to write a key block to the cache.
Key_writes
The number of physical writes of a key block to disk.
Last_query_cost
The total cost of the last compiled query as computed by the query optimizer. This is useful for comparing the cost of different query plans for the same query. The default value of 0 means that no query has been compiled yet. The default value is 0.
Last_query_cost
has session scope.The
Last_query_cost
value can be computed accurately only for simple "flat" queries, not complex queries such as those with subqueries orUNION
. For the latter, the value is set to 0.Last_query_partial_plans
The number of iterations the query optimizer made in execution plan construction for the previous query.
Last_query_cost
has session scope. This variable was added in MariaDB 5.6.5.Max_used_connections
The maximum number of connections that have been in use simultaneously since the server started.
Not_flushed_delayed_rows
The number of rows waiting to be written to nontransactional tables in
INSERT DELAYED
queues.Open_files
The number of files that are open. This count includes regular files opened by the server. It does not include other types of files such as sockets or pipes. Also, the count does not include files that storage engines open using their own internal functions rather than asking the server level to do so.
Open_streams
The number of streams that are open (used mainly for logging).
Open_table_definitions
The number of cached
.frm
files.Open_tables
The number of tables that are open.
Opened_files
The number of files that have been opened with
my_open()
(amysys
library function). Parts of the server that open files without using this function do not increment the count.Opened_table_definitions
The number of
.frm
files that have been cached.Opened_tables
The number of tables that have been opened. If
Opened-tables
is big, yourtable_open_cache
value is probably too small.Performance_schema_
xxx
Performance Schema status variables are listed in , "Performance Schema Status Variables".
Prepared_stmt_count
The current number of prepared statements. (The maximum number of statements is given by the
max_prepared_stmt_count
system variable.)Qcache_free_blocks
The number of free memory blocks in the query cache.
Qcache_free_memory
The amount of free memory for the query cache.
Qcache_hits
The number of query cache hits.
Qcache_inserts
The number of queries added to the query cache.
Qcache_lowmem_prunes
The number of queries that were deleted from the query cache because of low memory.
Qcache_not_cached
The number of noncached queries (not cacheable, or not cached due to the
query_cache_type
setting).Qcache_queries_in_cache
The number of queries registered in the query cache.
Qcache_total_blocks
The total number of blocks in the query cache.
Queries
The number of statements executed by the server. This variable includes statements executed within stored programs, unlike the
Questions
variable. It does not countCOM_PING
orCOM_STATISTICS
commands.Questions
The number of statements executed by the server. This includes only statements sent to the server by clients and not statements executed within stored programs, unlike the
Queries
variable. This variable does not countCOM_PING
,COM_STATISTICS
,COM_STMT_PREPARE
,COM_STMT_CLOSE
, orCOM_STMT_RESET
commands.Rpl_semi_sync_master_clients
The number of semisynchronous slaves.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_net_avg_wait_time
The average time in microseconds the master waited for a slave reply.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_net_wait_time
The total time in microseconds the master waited for slave replies.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_net_waits
The total number of times the master waited for slave replies.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_no_times
The number of times the master turned off semisynchronous replication.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_no_tx
The number of commits that were not acknowledged successfully by a slave.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_status
Whether semisynchronous replication currently is operational on the master. The value is
ON
if the plugin has been enabled and a commit acknowledgment has occurred. It isOFF
if the plugin is not enabled or the master has fallen back to asynchronous replication due to commit acknowledgment timeout.This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_timefunc_failures
The number of times the master failed when calling time functions such as
gettimeofday()
.This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_tx_avg_wait_time
The average time in microseconds the master waited for each transaction.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_tx_wait_time
The total time in microseconds the master waited for transactions.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_tx_waits
The total number of times the master waited for transactions.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_wait_pos_backtraverse
The total number of times the master waited for an event with binary coordinates lower than events waited for previously. This can occur when the order in which transactions start waiting for a reply is different from the order in which their binary log events are written.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_wait_sessions
The number of sessions currently waiting for slave replies.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_master_yes_tx
The number of commits that were acknowledged successfully by a slave.
This variable is available only if the master-side semisynchronous replication plugin is installed.
Rpl_semi_sync_slave_status
Whether semisynchronous replication currently is operational on the slave. This is
ON
if the plugin has been enabled and the slave I/O thread is running,OFF
otherwise.This variable is available only if the slave-side semisynchronous replication plugin is installed.
Select_full_join
The number of joins that perform table scans because they do not use indexes. If this value is not 0, you should carefully check the indexes of your tables.
Select_full_range_join
The number of joins that used a range search on a reference table.
Select_range
The number of joins that used ranges on the first table. This is normally not a critical issue even if the value is quite large.
Select_range_check
The number of joins without keys that check for key usage after each row. If this is not 0, you should carefully check the indexes of your tables.
Select_scan
The number of joins that did a full scan of the first table.
Slave_heartbeat_period
Shows the replication heartbeat interval (in seconds) on a replication slave.
Slave_last_heartbeat
Shows when the most recent heartbeat signal was received by a replication slave, as a
TIMESTAMP
value.Slave_open_temp_tables
The number of temporary tables that the slave SQL thread currently has open. If the value is greater than zero, it is not safe to shut down the slave; see , "Replication and Temporary Tables".
Slave_received_heartbeats
This counter increments with each replication heartbeat received by a replication slave since the last time that the slave was restarted or reset, or a
CHANGE MASTER TO
statement was issued.Slave_retried_transactions
The total number of times since startup that the replication slave SQL thread has retried transactions.
Slave_running
This is
ON
if this server is a replication slave that is connected to a replication master, and both the I/O and SQL threads are running; otherwise, it isOFF
.Slow_launch_threads
The number of threads that have taken more than
slow_launch_time
seconds to create.Slow_queries
The number of queries that have taken more than
long-query-time
seconds. See , "The Slow Query Log".Sort_merge_passes
The number of merge passes that the sort algorithm has had to do. If this value is large, you should consider increasing the value of the
sort_buffer_size
system variable.Sort_range
The number of sorts that were done using ranges.
Sort_rows
The number of sorted rows.
Sort_scan
The number of sorts that were done by scanning the table.
Ssl_accept_renegotiates
The number of negotiates needed to establish the connection.
Ssl_accepts
The number of accepted SSL connections.
Ssl_callback_cache_hits
The number of callback cache hits.
Ssl_cipher
The current SSL cipher (empty for non-SSL connections).
Ssl_cipher_list
The list of possible SSL ciphers.
Ssl_client_connects
The number of SSL connection attempts to an SSL-enabled master.
Ssl_connect_renegotiates
The number of negotiates needed to establish the connection to an SSL-enabled master.
Ssl_ctx_verify_depth
The SSL context verification depth (how many certificates in the chain are tested).
Ssl_ctx_verify_mode
The SSL context verification mode.
Ssl_default_timeout
The default SSL timeout.
Ssl_finished_accepts
The number of successful SSL connections to the server.
Ssl_finished_connects
The number of successful slave connections to an SSL-enabled master.
Ssl_server_not_after
The last date for which the SSL certificate is valid. This variable was added in MariaDB 5.6.3.
Ssl_server_not_before
The first date for which the SSL certificate is valid. This variable was added in MariaDB 5.6.3.
Ssl_session_cache_hits
The number of SSL session cache hits.
Ssl_session_cache_misses
The number of SSL session cache misses.
Ssl_session_cache_mode
The SSL session cache mode.
Ssl_session_cache_overflows
The number of SSL session cache overflows.
Ssl_session_cache_size
The SSL session cache size.
Ssl_session_cache_timeouts
The number of SSL session cache timeouts.
Ssl_sessions_reused
How many SSL connections were reused from the cache.
Ssl_used_session_cache_entries
How many SSL session cache entries were used.
Ssl_verify_depth
The verification depth for replication SSL connections.
Ssl_verify_mode
The verification mode for replication SSL connections.
Ssl_version
The SSL protocol version of the connection.
Table_locks_immediate
The number of times that a request for a table lock could be granted immediately.
Table_locks_waited
The number of times that a request for a table lock could not be granted immediately and a wait was needed. If this is high and you have performance problems, you should first optimize your queries, and then either split your table or tables or use replication.
Tc_log_max_pages_used
For the memory-mapped implementation of the log that is used by mysqld when it acts as the transaction coordinator for recovery of internal XA transactions, this variable indicates the largest number of pages used for the log since the server started. If the product of
Tc_log_max_pages_used
andTc_log_page_size
is always significantly less than the log size, the size is larger than necessary and can be reduced. (The size is set by the--log-tc-size
option. Currently, this variable is unused: It is unneeded for binary log-based recovery, and the memory-mapped recovery log method is not used unless the number of storage engines capable of two-phase commit is greater than one. (InnoDB
is the only applicable engine.)Tc_log_page_size
The page size used for the memory-mapped implementation of the XA recovery log. The default value is determined using
getpagesize()
. Currently, this variable is unused for the same reasons as described forTc_log_max_pages_used
.Tc_log_page_waits
For the memory-mapped implementation of the recovery log, this variable increments each time the server was not able to commit a transaction and had to wait for a free page in the log. If this value is large, you might want to increase the log size (with the
--log-tc-size
option). For binary log-based recovery, this variable increments each time the binary log cannot be closed because there are two-phase commits in progress. (The close operation waits until all such transactions are finished.)Threads_cached
The number of threads in the thread cache.
Threads_connected
The number of currently open connections.
Threads_created
The number of threads created to handle connections. If
Threads_created
is big, you may want to increase thethread_cache_size
value. The cache miss rate can be calculated asThreads_created
/Connections
.Threads_running
The number of threads that are not sleeping.
Uptime
The number of seconds that the server has been up.
Uptime_since_flush_status
The number of seconds since the most recent
FLUSH STATUS
statement.