Note
- For V4.3.x, this view was introduced in V4.3.5.
- For V4.2.x, this view was introduced in V4.2.2.
Purpose
The CDB_WR_SYSTEM_EVENT view displays the tenant-level wait events of all tenants after they are persisted.
Columns
| Column | Type | Nullable? | Description |
|---|---|---|---|
| TENANT_ID | bigint(20) | NO | Tenant ID. |
| CLUSTER_ID | bigint(20) | NO | Cluster ID. |
| SNAP_ID | bigint(20) | NO | Snapshot ID. |
| SVR_IP | varchar(46) | NO | IP address of the node. |
| SVR_PORT | bigint(20) | NO | Port number of the node. |
| EVENT_ID | bigint(20) | NO | Wait event ID. |
| EVENT_NAME | varchar(64) | YES | Wait event name. |
| WAIT_CLASS_ID | bigint(20) | YES | ID of the wait event category. |
| WAIT_CLASS | varchar(64) | YES | Name of the wait event category. |
| TOTAL_WAITS | bigint(20) | YES | Total number of wait events. |
| TOTAL_TIMEOUTS | bigint(20) | YES | Total number of timeouts. |
| TIME_WAITED_MICRO | bigint(20) | YES | Total wait time in microseconds. |
The following table describes the wait event categories and their corresponding wait event IDs in the WAIT_CLASS column of the view.
| Wait event category | Wait event ID | Description |
|---|---|---|
| OTHER | 100 | Wait events that do not belong to other categories. |
| APPLICATION | 101 | Wait events caused by client-side code. |
| CONFIGURATION | 102 | Wait events caused by insufficient resource configurations of databases or instances. |
| ADMINISTRATIVE | 103 | Wait events caused by commands entered by database administrators. |
| CONCURRENCY | 104 | Wait events caused by waiting for internal database resources. |
| COMMIT | 105 | Wait events related to log commits. |
| IDLE | 106 | Wait events caused by idle sessions waiting for tasks. |
| NETWORK | 107 | Wait events related to network communications. |
| USER_IO | 108 | Wait events caused by waiting for user I/O. |
| SYSTEM_IO | 109 | Wait events caused by waiting for I/O from background processes. |
| CLUSTER | 111 | Wait events related to clusters. |
Sample query
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