PROCESSLIST table provides
information about which threads are running.
PROCESSLIST table has these
The MySQL user who issued the statement. A value of
system userrefers to a nonclient thread spawned by the server to handle tasks internally. This could be the I/O or SQL thread used on replication slaves or a delayed-row handler. For
system user, there is no host specified in the
unauthenticated userrefers to a thread that has become associated with a client connection but for which authentication of the client user has not yet been done.
event_schedulerrefers to the thread that monitors scheduled events (see Section 20.4, “Using the Event Scheduler”).
The host name of the client issuing the statement (except for
system user, for which there is no host). The host name for TCP/IP connections is reported in
format to make it easier to determine which client is doing what.
The default database, if one is selected; otherwise
The type of command the thread is executing. For descriptions for thread commands, see Section 8.14, “Examining Thread Information”. The value of this column corresponds to the
COM_commands of the client/server protocol and
Com_status variables. See Section 5.1.9, “Server Status Variables”
The time in seconds that the thread has been in its current state. For a slave SQL thread, the value is the number of seconds between the timestamp of the last replicated event and the real time of the slave machine. See Section 17.2.1, “Replication Implementation Details”.
An action, event, or state that indicates what the thread is doing. Descriptions for
STATEvalues can be found at Section 8.14, “Examining Thread Information”.
Most states correspond to very quick operations. If a thread stays in a given state for many seconds, there might be a problem that needs to be investigated.
SHOW PROCESSLISTstatement, the value of
The statement the thread is executing, or
NULLif it is not executing any statement. The statement might be the one sent to the server, or an innermost statement if the statement executes other statements. For example, if a
CALLstatement executes a stored procedure that is executing a
INFOvalue shows the
PROCESSLISTtable is a nonstandard
Like the output from the
SHOW PROCESSLISTstatement, the
PROCESSLISTtable shows information only about your own threads, unless you have the
PROCESSprivilege, in which case you will see information about other threads, too. As an anonymous user, you cannot see any rows at all.
If an SQL statement refers to the
PROCESSLISTtable, MySQL populates the entire table once, when statement execution begins, so there is read consistency during the statement. There is no read consistency for a multi-statement transaction.
The following statements are equivalent:
SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST SHOW FULL PROCESSLIST