Note
This view is available starting with V1.4.
Purpose
This view displays the wait events on all OBServer nodes for the current tenant, and counts the number of occurrences, wait time, timeout count, and other metrics for each type of wait event.
Columns
| Column | Type | Nullable | Description |
|---|---|---|---|
| CON_ID | bigint(20) | NO | The tenant ID. |
| SVR_IP | varchar(46) | NO | The IP address of the server where the information is stored. |
| SVR_PORT | bigint(20) | NO | The port number of the server where the information is stored. |
| EVENT_ID | bigint(20) | NO | The ID of the wait event. |
| EVENT | varchar(64) | NO | The description of the wait event. |
| WAIT_CLASS_ID | bigint(20) | NO | The class ID of the wait event. |
| WAIT_CLASS# | bigint(20) | NO | The index of the class to which the wait event belongs. |
| WAIT_CLASS | varchar(64) | NO | The class to which the wait event belongs. |
| TOTAL_WAITS | bigint(20) | NO | The total number of wait events. |
| TOTAL_TIMEOUTS | bigint(20) | NO | The total number of timeouts. |
| TIME_WAITED | double | NO | The total wait time, in 10 ms. |
| AVERAGE_WAIT | double | NO | The average wait time, in 10 ms. |
| TIME_WAITED_MICRO | bigint(20) | NO | The total wait time, in microseconds. |
Sample query
Query all wait events of the current tenant on all nodes and display the first 10 records.
obclient [oceanbase]> SELECT * FROM oceanbase.GV$SYSTEM_EVENT LIMIT 10;
The query result is as follows:
+--------+----------------+----------+----------+----------------------------+---------------+-------------+---------------+-------------+----------------+-------------+----------------------+-------------------+
| CON_ID | SVR_IP | SVR_PORT | EVENT_ID | EVENT | WAIT_CLASS_ID | WAIT_CLASS# | WAIT_CLASS | TOTAL_WAITS | TOTAL_TIMEOUTS | TIME_WAITED | AVERAGE_WAIT | TIME_WAITED_MICRO |
+--------+----------------+----------+----------+----------------------------+---------------+-------------+---------------+-------------+----------------+-------------+----------------------+-------------------+
| 1002 | 11.xxx.xxx.xxx | 28825 | 10001 | db file data read | 108 | 8 | USER_IO | 6466 | 0 | 248.8259 | 0.038482199195793376 | 2488259 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 11001 | db file compact read | 109 | 9 | SYSTEM_IO | 480081 | 0 | 30589.1178 | 0.06371657657770252 | 305891178 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 11002 | db file compact write | 109 | 9 | SYSTEM_IO | 2426062 | 0 | 63913.4377 | 0.026344519513516143 | 639134377 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 11016 | palf read | 109 | 9 | SYSTEM_IO | 541222 | 0 | 8143.9096 | 0.015047262675944438 | 81439096 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 11017 | palf write | 109 | 9 | SYSTEM_IO | 19637686 | 0 | 483846.5034 | 0.024638671959618868 | 4838465034 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 13000 | sync rpc | 107 | 7 | NETWORK | 1533 | 0 | 1351.2232 | 0.88142413568167 | 13512232 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 13001 | mysql response wait client | 106 | 6 | IDLE | 20 | 0 | 0.037 | 0.00185 | 370 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 13004 | wait in request queue | 102 | 2 | CONFIGURATION | 11518452 | 0 | 26999.07 | 0.002343984243716083 | 269990700 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 15101 | default condition wait | 104 | 4 | CONCURRENCY | 5465549 | 0 | 206549.5945 | 0.03779118886318648 | 2065495945 |
| 1002 | 11.xxx.xxx.xxx | 28825 | 15102 | sleep wait | 106 | 6 | IDLE | 103 | 0 | 1023.8728 | 9.940512621359224 | 10238728 |
+--------+----------------+----------+----------+----------------------------+---------------+-------------+---------------+-------------+----------------+-------------+----------------------+-------------------+
10 rows in set
References
To view the current or previous wait events of all sessions:
To view all wait events at the session level:
To view the definitions of all wait events for the tenant: V$EVENT_NAME
For more information about wait events, see Common wait events.