Note
This parameter was introduced in OceanBase Database V2.2.30.
Description
writing_throttling_trigger_percentage specifies the upper limit of the write speed.
Limitations
Query the parameter
In the
systenant or a user tenant, you can execute theSHOW PARAMETERSstatement to query the parameter or query theGV$OB_PARAMETERSview for the parameter.Modify the parameter
You can modify the parameter in the
systenant or a user tenant.
Attributes
Attribute |
Description |
|---|---|
| Type | Integer |
| Default value | 60
NoteThe default value is changed from |
| Value range | [1, 100] |
| Modifiable | Yes. You can use the ALTER SYSTEM SET statement to modify the parameter. |
| Effective upon OBServer node restart | No. The setting takes effect immediately. |
Considerations
In OceanBase Database V4.0.0 and later, the default value of this parameter is changed to
60. This is because the throttling feature runs stably, and throttling will not be triggered in most business scenarios except upon traffic surges during data import. Even if throttling is triggered in data import, user experience is still higher than that with writing stopped. Therefore, this feature is enabled by default. To achieve smooth throttling, the default value is set to60instead of80. If this parameter is set to80, the remaining 20% of buffer must mitigate the pressure caused by the MemStore memory usage of 80%. This causes sharp throttling and greatly increases the response time of business.When the memory used by the MemStore reaches the threshold, the write speed limit is triggered. If this parameter is set to
100, write throttling is disabled.
Examples
Set the upper limit of the write speed to 60.
obclient> ALTER SYSTEM SET writing_throttling_trigger_percentage = 60;