PROCESSLIST
PROCESSLIST, just like SHOW PROCESSLIST, is used to view the requests that are being handled.
The PROCESSLIST table has additional columns not present in SHOW PROCESSLIST:
- A
MEMcolumn to show the memory used by the request that is being processed, in bytes. - A
TxnStartcolumn to show the start time of the transaction
USE information_schema;
DESC processlist;
+----------+---------------------+------+------+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+---------------------+------+------+---------+-------+
| ID | bigint(21) unsigned | NO | | 0 | |
| USER | varchar(16) | NO | | | |
| HOST | varchar(64) | NO | | | |
| DB | varchar(64) | YES | | NULL | |
| COMMAND | varchar(16) | NO | | | |
| TIME | int(7) | NO | | 0 | |
| STATE | varchar(7) | YES | | NULL | |
| INFO | binary(512) | YES | | NULL | |
| MEM | bigint(21) unsigned | YES | | NULL | |
| TxnStart | varchar(64) | NO | | | |
+----------+---------------------+------+------+---------+-------+
10 rows in set (0.00 sec)
SELECT * FROM processlist\G
*************************** 1. row ***************************
ID: 16
USER: root
HOST: 127.0.0.1
DB: information_schema
COMMAND: Query
TIME: 0
STATE: autocommit
INFO: SELECT * FROM processlist
MEM: 0
TxnStart:
1 row in set (0.00 sec)
Fields in the PROCESSLIST table are described as follows:
- ID: The ID of the user connection.
- USER: The name of the user who is executing
PROCESS. - HOST: The address that the user is connecting to.
- DB: The name of the currently connected default database.
- COMMAND: The command type that
PROCESSis executing. - TIME: The current execution duration of
PROCESS, in seconds. - STATE: The current connection state.
- INFO: The requested statement that is being processed.
- MEM: The memory used by the request that is being processed, in bytes.
- TxnStart: The start time of the transaction.
CLUSTER_PROCESSLIST
CLUSTER_PROCESSLIST is the cluster system table corresponding to PROCESSLIST. It is used to query the PROCESSLIST information of all TiDB nodes in the cluster. The table schema of CLUSTER_PROCESSLIST has one more column than PROCESSLIST, the INSTANCE column, which stores the address of the TiDB node this row of data is from.
SELECT * FROM information_schema.cluster_processlist;
+-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+
| INSTANCE | ID | USER | HOST | DB | COMMAND | TIME | STATE | INFO | MEM | TxnStart |
+-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+
| 10.0.1.22:10080 | 150 | u1 | 10.0.1.1 | test | Query | 0 | autocommit | select count(*) from usertable | 372 | 05-28 03:54:21.230(416976223923077223) |
| 10.0.1.22:10080 | 138 | root | 10.0.1.1 | test | Query | 0 | autocommit | SELECT * FROM information_schema.cluster_processlist | 0 | 05-28 03:54:21.230(416976223923077220) |
| 10.0.1.22:10080 | 151 | u1 | 10.0.1.1 | test | Query | 0 | autocommit | select count(*) from usertable | 372 | 05-28 03:54:21.230(416976223923077224) |
| 10.0.1.21:10080 | 15 | u2 | 10.0.1.1 | test | Query | 0 | autocommit | select max(field0) from usertable | 496 | 05-28 03:54:21.230(416976223923077222) |
| 10.0.1.21:10080 | 14 | u2 | 10.0.1.1 | test | Query | 0 | autocommit | select max(field0) from usertable | 496 | 05-28 03:54:21.230(416976223923077225) |
+-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+
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