PROCESSLIST
PROCESSLIST 和 SHOW PROCESSLIST 的功能一样,都是查看当前正在处理的请求。
PROCESSLIST 表比 SHOW PROCESSLIST 的结果多出下面几列:
DIGEST列:显示 SQL 语句的 digest。MEM列:显示正在处理的请求已使用的内存,单位是 byte。DISK列:显示磁盘空间使用情况,单位是 byte。TxnStart列:显示事务的开始时间。RESOURCE_GROUP列:显示对应的资源组名称。
1. USE information_schema;
2. DESC processlist;
1. +---------------------+---------------------+------+------+---------+-------+
2. | Field | Type | Null | Key | Default | Extra |
3. +---------------------+---------------------+------+------+---------+-------+
4. | ID | bigint(21) unsigned | NO | | 0 | |
5. | USER | varchar(16) | NO | | | |
6. | HOST | varchar(64) | NO | | | |
7. | DB | varchar(64) | YES | | NULL | |
8. | COMMAND | varchar(16) | NO | | | |
9. | TIME | int(7) | NO | | 0 | |
10. | STATE | varchar(7) | YES | | NULL | |
11. | INFO | longtext | YES | | NULL | |
12. | DIGEST | varchar(64) | YES | | | |
13. | MEM | bigint(21) unsigned | YES | | NULL | |
14. | DISK | bigint(21) unsigned | YES | | NULL | |
15. | TxnStart | varchar(64) | NO | | | |
16. | RESOURCE_GROUP | varchar(32) | NO | | | |
17. +---------------------+---------------------+------+------+---------+-------+
18. 13 rows in set (0.00 sec)
1. SELECT * FROM processlist\G
1. *************************** 1. row ***************************
2. ID: 2300033189772525975
3. USER: root
4. HOST: 127.0.0.1:51289
5. DB: NULL
6. COMMAND: Query
7. TIME: 0
8. STATE: autocommit
9. INFO: SELECT * FROM processlist
10. DIGEST: dbfaa16980ec628011029f0aaf0d160f4b040885240dfc567bf760d96d374f7e
11. MEM: 0
12. DISK: 0
13. TxnStart:
14. RESOURCE_GROUP: rg1
15. 1 row in set (0.00 sec)
PROCESSLIST 表各列的含义如下:
ID列:客户连接 ID。USER列:执行当前 PROCESS 的用户名。HOST列:客户连接的地址。DB列:当前连接的默认数据库名。COMMAND列:当前 PROCESS 执行的命令类型。TIME列:当前 PROCESS 的已经执行的时间,单位是秒。STATE列:当前连接的状态。INFO列:正在处理的请求语句。DIGEST列:SQL 语句的 digest。MEM列:正在处理的请求已使用的内存,单位是 byte。DISK列:磁盘空间使用情况,单位是 byte。TxnStart列:显示事务的开始时间。RESOURCE_GROUP列:显示对应的资源组名称。
CLUSTER_PROCESSLIST
CLUSTER_PROCESSLIST 是 PROCESSLIST 对应的集群系统表,用于查询集群中所有 TiDB 节点的 PROCESSLIST 信息。CLUSTER_PROCESSLIST 表结构上比 PROCESSLIST 多一列 INSTANCE,表示该行数据来自的 TiDB 节点地址。
1. SELECT * FROM information_schema.cluster_processlist;
1. +-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+----------------+
2. | INSTANCE | ID | USER | HOST | DB | COMMAND | TIME | STATE | INFO | MEM | TxnStart | RESOURCE_GROUP |
3. +-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+----------------+
5. | 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) | default |
6. | 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) | rg1 |
7. | 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) | rg2 |
8. | 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) | default |
9. | 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) | default |
10. +-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+----------------+
