Note
- For V4.3.x, this view is available starting with V4.3.5.
- For V4.2.x, this view is available starting with V4.2.2.
Purpose
The CDB_WR_SYSTEM_EVENT view displays the persisted tenant-level wait events for all tenants.
Columns
Column |
Type |
Nullable? |
Description |
|---|---|---|---|
| TENANT_ID | bigint(20) | NO | The tenant ID. |
| CLUSTER_ID | bigint(20) | NO | The cluster ID. |
| SNAP_ID | bigint(20) | NO | The snapshot ID. |
| SVR_IP | varchar(46) | NO | The IP address of the node. |
| SVR_PORT | bigint(20) | NO | The port number of the node. |
| EVENT_ID | bigint(20) | NO | The ID of the wait event. |
| EVENT_NAME | varchar(64) | YES | The name of the wait event. |
| WAIT_CLASS_ID | bigint(20) | YES | The ID of the wait event category. |
| WAIT_CLASS | varchar(64) | YES | The name of the wait event category. |
| TOTAL_WAITS | bigint(20) | YES | The total number of wait events. |
| TOTAL_TIMEOUTS | bigint(20) | YES | The total number of timeouts. |
| TIME_WAITED_MICRO | bigint(20) | YES | The total wait time. |
The following table describes the wait event categories and their corresponding IDs in the WAIT_CLASS column of the view.
Wait event category |
Wait event ID |
Description |
|---|---|---|
| OTHER | 100 | A wait event that does not belong to any other category. |
| APPLICATION | 101 | A wait event caused by client-side code. |
| CONFIGURATION | 102 | A wait event caused by insufficient database or instance resources. |
| ADMINISTRATIVE | 103 | A wait event caused by a database administrator command. |
| CONCURRENCY | 104 | A wait event for internal database resources. |
| COMMIT | 105 | A wait event related to log commit. |
| IDLE | 106 | A wait event for an inactive session. |
| NETWORK | 107 | A wait event related to network communication. |
| USER_IO | 108 | A wait event for user I/O. |
| SYSTEM_IO | 109 | A wait event for background process I/O. |
| CLUSTER | 111 | A wait event related to a cluster. |
Sample query
Query the persisted tenant-level wait events for tenant 1004 and display the first 10 records.
obclient [oceanbase]> SELECT * FROM oceanbase.CDB_WR_SYSTEM_EVENT WHERE TENANT_ID= 1004 LIMIT 10;
The query result is as follows:
+-----------+------------+---------+----------------+----------+----------+----------------------------------------------------+---------------+-------------+-------------+----------------+-------------------+
| TENANT_ID | CLUSTER_ID | SNAP_ID | SVR_IP | SVR_PORT | EVENT_ID | EVENT_NAME | WAIT_CLASS_ID | WAIT_CLASS | TOTAL_WAITS | TOTAL_TIMEOUTS | TIME_WAITED_MICRO |
+-----------+------------+---------+----------------+----------+----------+----------------------------------------------------+---------------+-------------+-------------+----------------+-------------------+
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 2 | latch: default spin rwlock wait | 104 | CONCURRENCY | 8 | 0 | 1339 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 3 | latch: default mutex wait | 104 | CONCURRENCY | 349 | 0 | 16079 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 8 | latch: trans ctx latch wait | 104 | CONCURRENCY | 6 | 0 | 15328 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 40 | latch: config lock wait | 104 | CONCURRENCY | 6 | 0 | 159968 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 99 | latch: tablet bucket lock wait | 104 | CONCURRENCY | 1 | 0 | 1177 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 197 | latch: weak read service cluster service lock wait | 104 | CONCURRENCY | 1 | 0 | 1 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 217 | latch: FIFO allocator lock wait | 104 | CONCURRENCY | 1 | 0 | 29 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 258 | latch: palf handle impl lock wait | 104 | CONCURRENCY | 4 | 0 | 185 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 278 | latch: max apply scn lock wait | 104 | CONCURRENCY | 1 | 0 | 21 |
| 1004 | 10001 | 1 | 172.xx.xxx.xxx | 2882 | 283 | latch: ls meta lock wait | 104 | CONCURRENCY | 34 | 0 | 4998 |
+-----------+------------+---------+----------------+----------+----------+----------------------------------------------------+---------------+-------------+-------------+----------------+-------------------+
10 rows in set