Tuning Aurora MySQL with wait events - Amazon Aurora

Tuning Aurora MySQL with wait events

The following table summarizes the Aurora MySQL wait events that most commonly indicate performance problems. The following wait events are a subset of the list in Aurora MySQL wait events.

Wait event Description

cpu

This event occurs when a thread is active in CPU or is waiting for CPU.

io/aurora_redo_log_flush

This event occurs when a session is writing persistent data to Aurora storage.

io/aurora_respond_to_client

This event occurs when a thread is waiting to return a result set to a client.

io/file/innodb/innodb_data_file

This event occurs when there are threads waiting on I/O operations from storage.

io/socket/sql/client_connection

This event occurs when a thread is in the process of handling a new connection.

io/table/sql/handler

This event occurs when work has been delegated to a storage engine.

synch/cond/mysys/my_thread_var::suspend

This event occurs when threads are suspended because they are waiting on a condition.

synch/cond/sql/MDL_context::COND_wait_status

This event occurs when there are threads waiting on a table metadata lock.

synch/mutex/innodb/aurora_lock_thread_slot_futex

This event occurs when one session has locked a row for an update, and another session tries to update the same row.

synch/mutex/innodb/buf_pool_mutex

This event occurs when a thread has acquired a lock on the InnoDB buffer pool to access a page in memory.

synch/mutex/innodb/fil_system_mutex

This event occurs when a session is waiting to access the tablespace memory cache.

synch/mutex/innodb/trx_sys_mutex

This event occurs when there is high database activity with a large number of transactions.

synch/rwlock/innodb/hash_table_locks

This event occurs when there is contention on modifying the hash table that maps the buffer cache.

synch/sxlock/innodb/hash_table_locks

This event occurs when pages not found in the buffer pool must be read from a file.