Note
For V4.0.0, this parameter is available starting with V4.0.0.
Description
ha_high_thread_score specifies the number of threads used for high-priority high-availability tasks.
Privilege requirements
Query the parameter
The
systenant and all user tenants can query this parameter by using theSHOW PARAMETERSstatement or theGV$OB_PARAMETERSview.Modify the parameter
The
systenant and user tenants can modify this parameter.
Attributes
| Attribute | Description |
|---|---|
| Type | Int |
| Default value | 0, which indicates that the default number of threads is 8 |
| Value range | [0, 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 V4.x, tasks related to high availability (HA), such as migration replication and backup and restore, are scheduled by the DagScheduler at the tenant level. To avoid resource contention, three HA-related parameters are set based on task priority and importance instead of task type. These parameters specify the number of threads used for different types of tasks:
ha_high_thread_score: specifies the number of threads used for high-priority HA tasks such as replication, rebuild, and restore.ha_mid_thread_score: specifies the number of threads used for medium-priority HA tasks such as migration.ha_low_thread_score: specifies the number of threads used for low-priority HA tasks such as backup, backup of backup, and backup cleanup.
Examples
Set the number of threads used for high-priority HA tasks in the current tenant to 10.
obclient> ALTER SYSTEM SET ha_high_thread_score =10;
References
- Set the number of threads used for medium-priority HA tasks: ha_mid_thread_score
- Set the number of threads used for low-priority HA tasks: ha_low_thread_score