Aurora MySQL global status variables - Amazon Aurora

Aurora MySQL global status variables

Aurora MySQL includes status variables from community MySQL and variables that are unique to Aurora. You can examine these variables to learn about what's happening inside the database engine. For more information about the status variables in community MySQL, see Server Status Variables in the community MySQL 8.0 documentation.

You can find the current values for Aurora MySQL global status variables by using a statement such as the following:

show global status like '%aurora%';
Note

Global status variables are cleared when the DB engine reboots.

The following table describes the global status variables that Aurora MySQL uses.

Name Description

AuroraDb_commits

The total number of commits since the last restart.

AuroraDb_commit_latency

The aggregate commit latency since the last restart.

AuroraDb_ddl_stmt_duration

The aggregate DDL latency since the last restart.

AuroraDb_select_stmt_duration

The aggregate SELECT statement latency since the last restart.

AuroraDb_insert_stmt_duration

The aggregate INSERT statement latency since the last restart.

AuroraDb_update_stmt_duration

The aggregate UPDATE statement latency since the last restart.

AuroraDb_delete_stmt_duration

The aggregate DELETE statement latency since the last restart.

Aurora_binlog_io_cache_allocated

The number of bytes allocated to the binlog I/O cache.

Aurora_binlog_io_cache_read_requests

The number of read requests made to the binlog I/O cache.

Aurora_binlog_io_cache_reads

The number of read requests that were served from the binlog I/O cache.

Aurora_enhanced_binlog

Indicates whether enhanced binlog is enabled or disabled for this DB instance. For more information, see Setting up enhanced binlog for Aurora MySQL.

Aurora_external_connection_count

The number of database connections to the DB instance, excluding RDS service connections used for database health checks.

Aurora_fast_insert_cache_hits

A counter that's incremented when the cached cursor is successfully retrieved and verified. For more information on the fast insert cache, see Amazon Aurora MySQL performance enhancements.

Aurora_fast_insert_cache_misses

A counter that's incremented when the cached cursor is no longer valid and Aurora performs a normal index traversal. For more information on the fast insert cache, see Amazon Aurora MySQL performance enhancements.

Aurora_fts_cache_memory_used

The amount of memory in bytes that the InnoDB full-text search system is using. This variable applies to Aurora MySQL version 3.07 and higher.

Aurora_fwd_master_dml_stmt_count

The total number of DML statements forwarded to this writer DB instance. This variable applies to Aurora MySQL version 2.

Aurora_fwd_master_dml_stmt_duration

The total duration of DML statements forwarded to this writer DB instance. This variable applies to Aurora MySQL version 2.

Aurora_fwd_master_errors_rpc_timeout

The number of times a forwarded connection failed to be established on the writer.

Aurora_fwd_master_errors_session_limit

The number of forwarded queries that get rejected due to session full on the writer.

Aurora_fwd_master_errors_session_timeout

The number of times a forwarding session is ended due to a timeout on the writer.

Aurora_fwd_master_open_sessions

The number of forwarded sessions on the writer DB instance. This variable applies to Aurora MySQL version 2.

Aurora_fwd_master_select_stmt_count

The total number of SELECT statements forwarded to this writer DB instance. This variable applies to Aurora MySQL version 2.

Aurora_fwd_master_select_stmt_duration

The total duration of SELECT statements forwarded to this writer DB instance. This variable applies to Aurora MySQL version 2.

Aurora_fwd_writer_dml_stmt_count

The total number of DML statements forwarded to this writer DB instance. This variable applies to Aurora MySQL version 3.

Aurora_fwd_writer_dml_stmt_duration

The total duration of DML statements forwarded to this writer DB instance. This variable applies to Aurora MySQL version 3.

Aurora_fwd_writer_errors_rpc_timeout

The number of times a forwarded connection failed to be established on the writer.

Aurora_fwd_writer_errors_session_limit

The number of forwarded queries that get rejected due to session full on the writer.

Aurora_fwd_writer_errors_session_timeout

The number of times a forwarding session is ended due to a timeout on the writer.

Aurora_fwd_writer_open_sessions

The number of forwarded sessions on the writer DB instance. This variable applies to Aurora MySQL version 3.

Aurora_fwd_writer_select_stmt_count

The total number of SELECT statements forwarded to this writer DB instance. This variable applies to Aurora MySQL version 3.

Aurora_fwd_writer_select_stmt_duration

The total duration of SELECT statements forwarded to this writer DB instance. This variable applies to Aurora MySQL version 3.

Aurora_lockmgr_buffer_pool_memory_used

The amount of buffer pool memory in bytes that the Aurora MySQL lock manager is using.

Aurora_lockmgr_memory_used

The amount of memory in bytes that the Aurora MySQL lock manager is using.

Aurora_ml_actual_request_cnt

The aggregate request count that Aurora MySQLmakes to the Aurora machine learning services across all queries run by users of the DB instance. For more information, see Using Amazon Aurora machine learning with Aurora MySQL.

Aurora_ml_actual_response_cnt

The aggregate response count that Aurora MySQL receives from the Aurora machine learning services across all queries run by users of the DB instance. For more information, see Using Amazon Aurora machine learning with Aurora MySQL.

Aurora_ml_cache_hit_cnt

The aggregate internal cache hit count that Aurora MySQL receives from the Aurora machine learning services across all queries run by users of the DB instance. For more information, see Using Amazon Aurora machine learning with Aurora MySQL.

Aurora_ml_logical_request_cnt

The number of logical requests that the DB instance has evaluated to be sent to the Aurora machine learning services since the last status reset. Depending on whether batching has been used, this value can be higher than Aurora_ml_actual_request_cnt. For more information, see Using Amazon Aurora machine learning with Aurora MySQL.

Aurora_ml_logical_response_cnt

The aggregate response count that Aurora MySQL receives from the Aurora machine learning services across all queries run by users of the DB instance. For more information, see Using Amazon Aurora machine learning with Aurora MySQL.

Aurora_ml_retry_request_cnt

The number of retried requests that the DB instance has sent to the Aurora machine learning services since the last status reset. For more information, see Using Amazon Aurora machine learning with Aurora MySQL.

Aurora_ml_single_request_cnt

The aggregate count of Aurora machine learning functions that are evaluated by non-batch mode across all queries run by users of the DB instance. For more information, see Using Amazon Aurora machine learning with Aurora MySQL.

aurora_oom_avoidance_recovery_state

Indicates whether Aurora out-of-memory (OOM) avoidance recovery is in the ACTIVE or INACTIVE state for this DB instance.

This variable applies to Aurora MySQL version 3.06.0 and higher.

aurora_oom_reserved_mem_enter_kb

Represents the threshold for entering the RESERVED state in Aurora's OOM handling mechanism.

When the available memory on the server falls below this threshold, aurora_oom_status changes to RESERVED, indicating that the server is approaching a critical level of memory usage.

This variable applies to Aurora MySQL version 3.06.0 and higher.

aurora_oom_reserved_mem_exit_kb

Represents the threshold for exiting the RESERVED state in Aurora's OOM handling mechanism.

When the available memory on the server rises above this threshold, aurora_oom_status reverts to NORMAL, indicating that the server has returned to a more stable state with sufficient memory resources.

This variable applies to Aurora MySQL version 3.06.0 and higher.

aurora_oom_status

Represents the current OOM status of this DB instance. When the value is NORMAL, it indicates that there are sufficient memory resources.

If the value changes to RESERVED, it indicates that the server has low available memory. Actions are taken based on the aurora_oom_response parameter configuration.

For more information, see Troubleshooting out-of-memory issues for Aurora MySQL databases.

This variable applies to Aurora MySQL version 3.06.0 and higher.

Aurora_pq_bytes_returned

The number of bytes for the tuple data structures transmitted to the head node during parallel queries. Divide by 16,384 to compare against Aurora_pq_pages_pushed_down.

Aurora_pq_max_concurrent_requests

The maximum number of parallel query sessions that can run concurrently on this Aurora DB instance. This is a fixed number that depends on the AWS DB instance class.

Aurora_pq_pages_pushed_down

The number of data pages (each with a fixed size of 16 KiB) where parallel query avoided a network transmission to the head node.

Aurora_pq_request_attempted

The number of parallel query sessions requested. This value might represent more than one session per query, depending on SQL constructs such as subqueries and joins.

Aurora_pq_request_executed

The number of parallel query sessions run successfully.

Aurora_pq_request_failed

The number of parallel query sessions that returned an error to the client. In some cases, a request for a parallel query might fail, for example due to a problem in the storage layer. In these cases, the query part that failed is retried using the nonparallel query mechanism. If the retried query also fails, an error is returned to the client and this counter is incremented.

Aurora_pq_request_in_progress

The number of parallel query sessions currently in progress. This number applies to the particular Aurora DB instance that you are connected to, not the entire Aurora DB cluster. To see if a DB instance is close to its concurrency limit, compare this value to Aurora_pq_max_concurrent_requests.

Aurora_pq_request_not_chosen

The number of times parallel query wasn't chosen to satisfy a query. This value is the sum of several other more granular counters. An EXPLAIN statement can increment this counter even though the query isn't actually performed.

Aurora_pq_request_not_chosen_below_min_rows

The number of times parallel query wasn't chosen due to the number of rows in the table. An EXPLAIN statement can increment this counter even though the query isn't actually performed.

Aurora_pq_request_not_chosen_column_bit

The number of parallel query requests that use the nonparallel query processing path because of an unsupported data type in the list of projected columns.

Aurora_pq_request_not_chosen_column_geometry

The number of parallel query requests that use the nonparallel query processing path because the table has columns with the GEOMETRY data type. For information about Aurora MySQL versions that remove this limitation, see Upgrading parallel query clusters to Aurora MySQL version 3.

Aurora_pq_request_not_chosen_column_lob

The number of parallel query requests that use the nonparallel query processing path because the table has columns with a LOB data type, or VARCHAR columns that are stored externally due to the declared length. For information about Aurora MySQL versions that remove this limitation, see Upgrading parallel query clusters to Aurora MySQL version 3.

Aurora_pq_request_not_chosen_column_virtual

The number of parallel query requests that use the nonparallel query processing path because the table contains a virtual column.

Aurora_pq_request_not_chosen_custom_charset

The number of parallel query requests that use the nonparallel query processing path because the table has columns with a custom character set.

Aurora_pq_request_not_chosen_fast_ddl

The number of parallel query requests that use the nonparallel query processing path because the table is currently being altered by a fast DDL ALTER statement.

Aurora_pq_request_not_chosen_few_pages_outside_buffer_pool

The number of times parallel query wasn't chosen, even though less than 95 percent of the table data was in the buffer pool, because there wasn't enough unbuffered table data to make parallel query worthwhile.

Aurora_pq_request_not_chosen_full_text_index

The number of parallel query requests that use the nonparallel query processing path because the table has full-text indexes.

Aurora_pq_request_not_chosen_high_buffer_pool_pct

The number of times parallel query wasn't chosen because a high percentage of the table data (currently, greater than 95 percent) was already in the buffer pool. In these cases, the optimizer determines that reading the data from the buffer pool is more efficient. An EXPLAIN statement can increment this counter even though the query isn't actually performed.

Aurora_pq_request_not_chosen_index_hint

The number of parallel query requests that use the nonparallel query processing path because the query includes an index hint.

Aurora_pq_request_not_chosen_innodb_table_format

The number of parallel query requests that use the nonparallel query processing path because the table uses an unsupported InnoDB row format. Aurora parallel query only applies to the COMPACT, REDUNDANT, and DYNAMIC row formats.

Aurora_pq_request_not_chosen_long_trx

The number of parallel query requests that used the nonparallel query processing path, due to the query being started inside a long-running transaction. An EXPLAIN statement can increment this counter even though the query isn't actually performed.

Aurora_pq_request_not_chosen_no_where_clause

The number of parallel query requests that use the nonparallel query processing path because the query doesn't include any WHERE clause.

Aurora_pq_request_not_chosen_range_scan

The number of parallel query requests that use the nonparallel query processing path because the query uses a range scan on an index.

Aurora_pq_request_not_chosen_row_length_too_long

The number of parallel query requests that use the nonparallel query processing path because the total combined length of all the columns is too long.

Aurora_pq_request_not_chosen_small_table

The number of times parallel query wasn't chosen due to the overall size of the table, as determined by number of rows and average row length. An EXPLAIN statement can increment this counter even though the query isn't actually performed.

Aurora_pq_request_not_chosen_temporary_table

The number of parallel query requests that use the nonparallel query processing path because the query refers to temporary tables that use the unsupported MyISAM or memory table types.

Aurora_pq_request_not_chosen_tx_isolation

The number of parallel query requests that use the nonparallel query processing path because query uses an unsupported transaction isolation level. On reader DB instances, parallel query only applies to the REPEATABLE READ and READ COMMITTED isolation levels.

Aurora_pq_request_not_chosen_update_delete_stmts

The number of parallel query requests that use the nonparallel query processing path because the query is part of an UPDATE or DELETE statement.

Aurora_pq_request_not_chosen_unsupported_access

The number of parallel query requests that use the nonparallel query processing path because the WHERE clause doesn't meet the criteria for parallel query. This result can occur if the query doesn't require a data-intensive scan, or if the query is a DELETE or UPDATE statement.

Aurora_pq_request_not_chosen_unsupported_storage_type

The number of parallel query requests that use the nonparallel query processing path because the Aurora MySQL DB cluster isn't using a supported Aurora cluster storage configuration. For more information, see Limitations.

This parameter applies to Aurora MySQL version 3.04 and higher.

Aurora_pq_request_throttled

The number of times parallel query wasn't chosen due to the maximum number of concurrent parallel queries already running on a particular Aurora DB instance.

Aurora_repl_bytes_received

Number of bytes replicated to an Aurora MySQL reader database instance since the last restart. For more information, see Replication with Amazon Aurora MySQL.

Aurora_reserved_mem_exceeded_incidents

The number of times since the last restart that the engine has exceeded reserved memory limits. If aurora_oom_response is configured, this threshold defines when out-of-memory (OOM) avoidance activities are triggered. For more information on the Aurora MySQL OOM response, see Troubleshooting out-of-memory issues for Aurora MySQL databases.

aurora_temptable_max_ram_allocation

The maximum amount of memory, in bytes, used at any point by internal temporary tables since the last restart.

aurora_temptable_ram_allocation

The current amount of memory, in bytes, used by internal temporary tables.

Aurora_thread_pool_thread_count

The current number of threads in the Aurora thread pool. For more information on the thread pool in Aurora MySQL, see Thread pool.

Aurora_tmz_version

Denotes the current version of the time zone information used by the DB cluster. The values follow the Internet Assigned Numbers Authority (IANA) format: YYYYsuffix, for example 2022a and 2023c.

This parameter applies to Aurora MySQL version 2.12 and higher, and version 3.04 and higher.

Aurora_zdr_oom_threshold

Represents the memory threshold, in kilobytes (KB), for an Aurora DB instance to initiate a zero downtime restart (ZDR) to recover from potential memory-related issues.

server_aurora_das_running

Indicates whether Database Activity Streams (DAS) are enabled or disabled on this DB instance. For more information, see Monitoring Amazon Aurora with Database Activity Streams.

MySQL status variables that don't apply to Aurora MySQL

Because of architectural differences between Aurora MySQL and MySQL, some MySQL status variables don't apply to Aurora MySQL.

The following MySQL status variables don't apply to Aurora MySQL. This list isn't exhaustive.

  • innodb_buffer_pool_bytes_dirty

  • innodb_buffer_pool_pages_dirty

  • innodb_buffer_pool_pages_flushed

Aurora MySQL version 3 removes the following status variables that were in Aurora MySQL version 2:

  • AuroraDb_lockmgr_bitmaps0_in_use

  • AuroraDb_lockmgr_bitmaps1_in_use

  • AuroraDb_lockmgr_bitmaps_mem_used

  • AuroraDb_thread_deadlocks

  • available_alter_table_log_entries

  • Aurora_lockmgr_memory_used

  • Aurora_missing_history_on_replica_incidents

  • Aurora_new_lock_manager_lock_release_cnt

  • Aurora_new_lock_manager_lock_release_total_duration_micro

  • Aurora_new_lock_manager_lock_timeout_cnt

  • Aurora_total_op_memory

  • Aurora_total_op_temp_space

  • Aurora_used_alter_table_log_entries

  • Aurora_using_new_lock_manager

  • Aurora_volume_bytes_allocated

  • Aurora_volume_bytes_left_extent

  • Aurora_volume_bytes_left_total

  • Com_alter_db_upgrade

  • Compression

  • External_threads_connected

  • Innodb_available_undo_logs

  • Last_query_cost

  • Last_query_partial_plans

  • Slave_heartbeat_period

  • Slave_last_heartbeat

  • Slave_received_heartbeats

  • Slave_retried_transactions

  • Slave_running

  • Time_since_zero_connections

These MySQL status variables are available in Aurora MySQL version 2, but they aren't available in Aurora MySQL version 3:

  • Innodb_redo_log_enabled

  • Innodb_undo_tablespaces_total

  • Innodb_undo_tablespaces_implicit

  • Innodb_undo_tablespaces_explicit

  • Innodb_undo_tablespaces_active