# Tuning Aurora MySQL with wait events
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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](AuroraMySQL.Reference.Waitevents.md).


| Wait event | Description | 
| --- | --- | 
| [cpu](ams-waits.cpu.md) | This event occurs when a thread is active in CPU or is waiting for CPU. | 
| [io/aurora\_redo\_log\_flush](ams-waits.io-auredologflush.md) | This event occurs when a session is writing persistent data to Aurora storage. | 
| [io/aurora\_respond\_to\_client](ams-waits.respond-to-client.md) | This event occurs when a thread is waiting to return a result set to a client. | 
| [io/redo\_log\_flush](ams-waits.io-redologflush.md) | This event occurs when a session is writing persistent data to Aurora storage. | 
| [io/socket/sql/client\_connection](ams-waits.client-connection.md) | This event occurs when a thread is in the process of handling a new connection. | 
| [io/table/sql/handler](ams-waits.waitio.md) | This event occurs when work has been delegated to a storage engine.  | 
| [synch/cond/innodb/row\_lock\_wait](ams-waits.row-lock-wait.md) | This event occurs when one session has locked a row for an update, and another session tries to update the same row. | 
| [synch/cond/innodb/row\_lock\_wait\_cond](ams-waits.row-lock-wait-cond.md) | This event occurs when one session has locked a row for an update, and another session tries to update the same row. | 
| [synch/cond/sql/MDL\_context::COND\_wait\_status](ams-waits.cond-wait-status.md) | This event occurs when there are threads waiting on a table metadata lock. | 
| [synch/mutex/innodb/aurora\_lock\_thread\_slot\_futex](ams-waits.waitsynch.md) | 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](ams-waits.bufpoolmutex.md) | 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](ams-waits.innodb-fil-system-mutex.md) | This event occurs when a session is waiting to access the tablespace memory cache. | 
| [synch/mutex/innodb/trx\_sys\_mutex](ams-waits.trxsysmutex.md) | This event occurs when there is high database activity with a large number of transactions. | 
| [synch/sxlock/innodb/hash\_table\_locks](ams-waits.sx-lock-hash-table-locks.md) | This event occurs when pages not found in the buffer pool must be read from a file. | 
| [synch/mutex/innodb/temp\_pool\_manager\_mutex](ams-waits.io-temppoolmanager.md) | This event occurs when a session is waiting to acquire a mutex for managing the pool of session temporary tablespaces.  |