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13.7.5.30. SHOW PROCESSLIST Syntax

SHOW [FULL] PROCESSLIST

SHOW PROCESSLIST shows you which threads are running. You can also get this information from the INFORMATION_SCHEMA PROCESSLIST table or the mysqladmin processlist command. If you have the PROCESS privilege, you can see all threads. Otherwise, you can see only your own threads (that is, threads associated with the MySQL account that you are using). If you do not use the FULL keyword, only the first 100 characters of each statement are shown in the Info field.

Process information is also available from the performance_schema.threads table. However, access to threads does not require a mutex and has minimal impact on server performance. INFORMATION_SCHEMA.PROCESSLIST and SHOW PROCESSLIST have negative performance consequences because they require a mutex. threads also shows information about background threads, which INFORMATION_SCHEMA.PROCESSLIST and SHOW PROCESSLIST do not. This means that threads can be used to monitor activity the other thread information sources cannot.

The SHOW PROCESSLIST statement is very useful if you get the "too many connections" error message and want to find out what is going on. MySQL reserves one extra connection to be used by accounts that have the SUPER privilege, to ensure that administrators should always be able to connect and check the system (assuming that you are not giving this privilege to all your users).

Threads can be killed with the KILL statement. See Section 13.7.6.4, "KILL Syntax".

Here is an example of SHOW PROCESSLIST output:

mysql> SHOW FULL PROCESSLIST\G*************************** 1. row ***************************Id: 1User: system userHost:db: NULLCommand: ConnectTime: 1030455State: Waiting for master to send eventInfo: NULL*************************** 2. row ***************************Id: 2User: system userHost:db: NULLCommand: ConnectTime: 1004State: Has read all relay log; waiting for the slave       I/O thread to update itInfo: NULL*************************** 3. row ***************************Id: 3112User: replikatorHost: artemis:2204db: NULLCommand: Binlog DumpTime: 2144State: Has sent all binlog to slave; waiting for binlog to be updatedInfo: NULL*************************** 4. row ***************************Id: 3113User: replikatorHost: iconnect2:45781db: NULLCommand: Binlog DumpTime: 2086State: Has sent all binlog to slave; waiting for binlog to be updatedInfo: NULL*************************** 5. row ***************************Id: 3123User: stefanHost: localhostdb: apollonCommand: QueryTime: 0State: NULLInfo: SHOW FULL PROCESSLIST5 rows in set (0.00 sec)

The columns produced by SHOW PROCESSLIST have the following meanings: