# Tuning Aurora MySQL with wait events
<a name="AuroraMySQL.Managing.Tuning.wait-events"></a>

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\$1redo\$1log\$1flush](ams-waits.io-auredologflush.md)  |  This event occurs when a session is writing persistent data to Aurora storage.  | 
|  [io/aurora\$1respond\$1to\$1client](ams-waits.respond-to-client.md)  |  This event occurs when a thread is waiting to return a result set to a client.  | 
|  [io/redo\$1log\$1flush](ams-waits.io-redologflush.md)  |  This event occurs when a session is writing persistent data to Aurora storage.  | 
|  [io/socket/sql/client\$1connection](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\$1lock\$1wait](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\$1lock\$1wait\$1cond](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\$1context::COND\$1wait\$1status](ams-waits.cond-wait-status.md)  |  This event occurs when there are threads waiting on a table metadata lock.  | 
|  [synch/mutex/innodb/aurora\$1lock\$1thread\$1slot\$1futex](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\$1pool\$1mutex](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\$1system\$1mutex](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\$1sys\$1mutex](ams-waits.trxsysmutex.md)  |  This event occurs when there is high database activity with a large number of transactions.  | 
|  [synch/sxlock/innodb/hash\$1table\$1locks](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\$1pool\$1manager\$1mutex](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.   |