Note
This parameter is available starting with V4.0.0.
Description
ha_mid_thread_score specifies the number of current working threads for the mid-priority thread in high availability.
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 working threads is 4 |
| 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 recovery, are scheduled and executed by the DagScheduler at the tenant level. Considering the limited thread resources of each tenant, instead of configuring parameters based on specific task types, three HA-related parameters are set based on task priority and importance. Each parameter corresponds to different task types:
ha_high_thread_score: specifies the number of threads for the high-priority HA task queue, such as replication, rebuild, and recovery.ha_mid_thread_score: specifies the number of threads for the mid-priority HA task queue, such as migration.ha_low_thread_score: specifies the number of threads for the low-priority HA task queue, such as backup, backup of backup, and backup cleanup.
Examples
Set the number of current working threads for the mid-priority thread in high availability to 10.
obclient> ALTER SYSTEM SET ha_mid_thread_score =10;