mysql:show [full] processlist
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references:http://dev.mysql.com/doc/refman/5.5/en/thread-information.html
命令:show [full] processlist
Each process list entry contains several pieces of information:
Id
is the connection identifier for the client associated with the thread.User
andHost
indicate the account associated with the thread.db
is the default database for the thread, orNULL
if none is selected.Command
andState
indicate what the thread is doing.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.
Time
indicates how long the thread has been in its current state. The thread's notion of the current time may be altered in some cases: The thread can change the time withSET TIMESTAMP =
. For a thread running on a slave that is processing events from the master, the thread time is set to the time found in the events and thus reflects current time on the master and not the slave.value
Info
contains the text of the statement being executed by the thread, orNULL
if it is not executing one. By default, this value contains only the first 100 characters of the statement. To see the complete statements, useSHOW FULL PROCESSLIST
.
Command values
- Binlog Dump:This is a thread on a master server for sending binary log contents to a slave server.
Change user
:The thread is executing a change-user operation.
Close stmt:
The thread is closing a prepared statement.Connect
:A replication slave is connected to its master.Connect Out:
A replication slave is connecting to its master.Create DB
:The thread is executing a create-database operation.Daemon
:This thread is internal to the server, not a thread that services a client connection.Debug
:The thread is generating debugging information.Delayed insert
:The thread is a delayed-insert handler.Drop DB
:The thread is executing a drop-database operation.Error
Execute
:The thread is executing a prepared statement.Fetch
:The thread is fetching the results from executing a prepared statement.Field List
:The thread is retrieving information for table columns.Init DB
:The thread is selecting a default database.Kill
:The thread is killing another thread.Long Data
:The thread is retrieving long data in the result of executing a prepared statement.Ping
:The thread is handling a server-ping request.Prepare
:The thread is preparing a prepared statement.Processlist
:The thread is producing information about server threads.Query
:The thread is executing a statement.Quit
:The thread is terminating.Refresh
:The thread is flushing table, logs, or caches, or resetting status variable or replication server information.Register Slave
:The thread is registering a slave server.Reset stmt
:The thread is resetting a prepared statement.Set option
:The thread is setting or resetting a client statement-execution option.Shutdown
:The thread is shutting down the server.Sleep
:The thread is waiting for the client to send a new statement to it.Statistics
: The thread is producing server-status information.Table Dump
: The thread is sending table contents to a slave server.Time
: Unused.
General State values
After create
This occurs when the thread creates a table (including internal temporary tables), at the end of the function that creates the table. This state is used even if the table could not be created due to some error.
Analyzing
The thread is calculating a
MyISAM
table key distributions (for example, forANALYZE TABLE
).checking permissions
The thread is checking whether the server has the required privileges to execute the statement.
Checking table
The thread is performing a table check operation.
cleaning up
The thread has processed one command and is preparing to free memory and reset certain state variables.
closing tables
The thread is flushing the changed table data to disk and closing the used tables. This should be a fast operation. If not, verify that you do not have a full disk and that the disk is not in very heavy use.
converting HEAP to MyISAM
The thread is converting an internal temporary table from a
MEMORY
table to an on-diskMyISAM
table.copy to tmp table
The thread is processing an
ALTER TABLE
statement. This state occurs after the table with the new structure has been created but before rows are copied into it.Copying to group table
If a statement has different
ORDER BY
andGROUP BY
criteria, the rows are sorted by group and copied to a temporary table.Copying to tmp table
The server is copying to a temporary table in memory.
Copying to tmp table on disk
The server is copying to a temporary table on disk. The temporary result set has become too large (seeSection 8.4.4, “How MySQL Uses Internal Temporary Tables”). Consequently, the thread is changing the temporary table from in-memory to disk-based format to save memory.
Creating index
The thread is processing
ALTER TABLE ... ENABLE KEYS
for aMyISAM
table.Creating sort index
The thread is processing a
SELECT
that is resolved using an internal temporary table.creating table
The thread is creating a table. This includes creation of temporary tables.
Creating tmp table
The thread is creating a temporary table in memory or on disk. If the table is created in memory but later is converted to an on-disk table, the state during that operation will be
Copying to tmp table on disk
.deleting from main table
The server is executing the first part of a multiple-table delete. It is deleting only from the first table, and saving columns and offsets to be used for deleting from the other (reference) tables.
deleting from reference tables
The server is executing the second part of a multiple-table delete and deleting the matched rows from the other tables.
discard_or_import_tablespace
The thread is processing an
ALTER TABLE ... DISCARD TABLESPACE
orALTER TABLE ... IMPORT TABLESPACE
statement.end
This occurs at the end but before the cleanup of
ALTER TABLE
,CREATE VIEW
,DELETE
,INSERT
,SELECT
, orUPDATE
statements.executing
The thread has begun executing a statement.
Execution of init_command
The thread is executing statements in the value of the
init_command
system variable.freeing items
The thread has executed a command. Some freeing of items done during this state involves the query cache. This state is usually followed by
cleaning up
.Flushing tables
The thread is executing
FLUSH TABLES
and is waiting for all threads to close their tables.FULLTEXT initialization
The server is preparing to perform a natural-language full-text search.
init
This occurs before the initialization of
ALTER TABLE
,DELETE
,INSERT
,SELECT
, orUPDATE
statements. Actions taken by the server in this state include flushing the binary log, theInnoDB
log, and some query cache cleanup operations.For the
end
state, the following operations could be happening:Removing query cache entries after data in a table is changed
Writing an event to the binary log
Freeing memory buffers, including for blobs
Killed
Someone has sent a
KILL
statement to the thread and it should abort next time it checks the kill flag. The flag is checked in each major loop in MySQL, but in some cases it might still take a short time for the thread to die. If the thread is locked by some other thread, the kill takes effect as soon as the other thread releases its lock.Locked
The query is locked by another query.
As of MySQL 5.5.3, this state was removed because it was equivalent to the
Table lock
state and no longer appears inSHOW PROCESSLIST
output.logging slow query
The thread is writing a statement to the slow-query log.
NULL
This state is used for the
SHOW PROCESSLIST
state.login
The initial state for a connection thread until the client has been authenticated successfully.
manage keys
The server is enabling or disabling a table index.
Opening tables
,Opening table
The thread is trying to open a table. This is should be very fast procedure, unless something prevents opening. For example, an
ALTER TABLE
or aLOCK TABLE
statement can prevent opening a table until the statement is finished. It is also worth checking that yourtable_open_cache
value is large enough.optimizing
The server is performing initial optimizations for a query.
preparing
This state occurs during query optimization.
Purging old relay logs
The thread is removing unneeded relay log files.
query end
This state occurs after processing a query but before the
freeing items
state.Reading from net
The server is reading a packet from the network.
Removing duplicates
The query was using
SELECT DISTINCT
in such a way that MySQL could not optimize away the distinct operation at an early stage. Because of this, MySQL requires an extra stage to remove all duplicated rows before sending the result to the client.removing tmp table
The thread is removing an internal temporary table after processing a
SELECT
statement. This state is not used if no temporary table was created.rename
The thread is renaming a table.
rename result table
The thread is processing an
ALTER TABLE
statement, has created the new table, and is renaming it to replace the original table.Reopen tables
The thread got a lock for the table, but noticed after getting the lock that the underlying table structure changed. It has freed the lock, closed the table, and is trying to reopen it.
Repair by sorting
The repair code is using a sort to create indexes.
Repair done
The thread has completed a multi-threaded repair for a
MyISAM
table.Repair with keycache
The repair code is using creating keys one by one through the key cache. This is much slower than
Repair by sorting
.Rolling back
The thread is rolling back a transaction.
Saving state
For
MyISAM
table operations such as repair or analysis, the thread is saving the new table state to the.MYI
file header. State includes information such as number of rows, theAUTO_INCREMENT
counter, and key distributions.Searching rows for update
The thread is doing a first phase to find all matching rows before updating them. This has to be done if the
UPDATE
is changing the index that is used to find the involved rows.Sending data
The thread is reading and processing rows for a
SELECT
statement, and sending data to the client. Because operations occurring during this state tend to perform large amounts of disk access (reads), it is often the longest-running state over the lifetime of a given query.setup
The thread is beginning an
ALTER TABLE
operation.Sorting for group
The thread is doing a sort to satisfy a
GROUP BY
.Sorting for order
The thread is doing a sort to satisfy a
ORDER BY
.Sorting index
The thread is sorting index pages for more efficient access during a
MyISAM
table optimization operation.Sorting result
For a
SELECT
statement, this is similar toCreating sort index
, but for nontemporary tables.statistics
The server is calculating statistics to develop a query execution plan. If a thread is in this state for a long time, the server is probably disk-bound performing other work.
System lock
The thread is going to request or is waiting for an internal or external system lock for the table. If this state is being caused by requests for external locks and you are not using multiplemysqld servers that are accessing the same
MyISAM
tables, you can disable external system locks with the--skip-external-locking
option. However, external locking is disabled by default, so it is likely that this option will have no effect. ForSHOW PROFILE
, this state means the thread is requesting the lock (not waiting for it).Table lock
The next thread state after
System lock
. The thread has acquired an external lock and is going to request an internal table lock.This state was replaced in MySQL 5.5.6 with
Waiting for table level lock
.update
The thread is getting ready to start updating the table.
Updating
The thread is searching for rows to update and is updating them.
updating main table
The server is executing the first part of a multiple-table update. It is updating only the first table, and saving columns and offsets to be used for updating the other (reference) tables.
updating reference tables
The server is executing the second part of a multiple-table update and updating the matched rows from the other tables.
User lock
The thread is going to request or is waiting for an advisory lock requested with a
GET_LOCK()
call. ForSHOW PROFILE
, this state means the thread is requesting the lock (not waiting for it).User sleep
The thread has invoked a
SLEEP()
call.Waiting for all running commits to finish
A statement that causes an explicit or implicit commit is waiting for release of a read lock. This state was removed in MySQL 5.5.8;
Waiting for commit lock
is used instead.Waiting for commit lock
A statement that causes an explicit or implicit commit is waiting for release of a read lock or
FLUSH TABLES WITH READ LOCK
is waiting for a commit lock. This state was added in MySQL 5.5.8.Waiting for global read lock
FLUSH TABLES WITH READ LOCK
is waiting for a global read lock or the globalread_only
system variable is being set.Waiting for release of readlock
The thread is waiting for a global read lock obtained by another thread (with
FLUSH TABLES WITH READ LOCK
) to be released. This state was removed in MySQL 5.5.8;Waiting for global read lock
orWaiting for commit lock
are used instead.Waiting for tables
,Waiting for table
,Waiting for table flush
The thread got a notification that the underlying structure for a table has changed and it needs to reopen the table to get the new structure. However, to reopen the table, it must wait until all other threads have closed the table in question.
This notification takes place if another thread has used
FLUSH TABLES
or one of the following statements on the table in question:FLUSH TABLES
,tbl_name
ALTER TABLE
,RENAME TABLE
,REPAIR TABLE
,ANALYZE TABLE
, orOPTIMIZE TABLE
.In MySQL 5.5.6,
Waiting for table
was replaced withWaiting for table flush
.Waiting for
lock_type
lockThe server is waiting to acquire a lock, where
lock_type
indicates the type of lock:Waiting for event metadata lock
(added in MySQL 5.5.8)Waiting for global metadata lock
(replaced byWaiting for global read lock
in MySQL 5.5.8)Waiting for global read lock
(added in MySQL 5.5.8)Waiting for schema metadata lock
Waiting for stored function metadata lock
Waiting for stored procedure metadata lock
Waiting for table level lock
Waiting for table metadata lock
Waiting for trigger metadata lock
(added in MySQL 5.5.8)
Waiting on cond
A generic state in which the thread is waiting for a condition to become true. No specific state information is available.
Waiting to get readlock
The thread has issued a
FLUSH TABLES WITH READ LOCK
statement to obtain a global read lock and is waiting to obtain the lock. This state was removed in MySQL 5.5.8;Waiting for global read lock
is used instead.Writing to net
The server is writing a packet to the network.
- others:
- Delayed-Insert Thread States:
- Query Cache Thread States: http://dev.mysql.com/doc/refman/5.5/en/query-cache-thread-states.html
- Replication Master Thread States :
- Replication Slave I/O Thread States
- Replication Slave SQL Thread States
- Replication Slave Connection Thread States
- MySQL Cluster Thread States
- Event Scheduler Thread States
- Delayed-Insert Thread States:
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