Note
For V4.0.0, this parameter is available starting with V4.0.0.
Description
ha_mid_thread_score specifies the number of threads currently working for the middle-priority thread in high availability.
Privilege requirements
Query the parameter
systenant and all user tenants can use theSHOW PARAMETERSstatement or theGV$OB_PARAMETERSview to query this parameter.Modify the parameter
systenant and user tenants can modify this parameter.
Attributes
| Attribute | Description |
|---|---|
| Type | Int |
| Default value | 0, indicating 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 by the DagScheduler at the tenant level. Considering the limited thread resources of each tenant, instead of distinguishing parameters based on 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 currently working for the high-priority HA task queue, such as replication, rebuild, and recovery.ha_mid_thread_score: specifies the number of threads currently working for the middle-priority HA task queue, such as migration.ha_low_thread_score: specifies the number of threads currently working for the low-priority HA task queue, such as backup, backup of backup, and backup cleanup.
Examples
Set the number of threads currently working for the middle-priority thread in high availability to 10.
obclient> ALTER SYSTEM SET ha_mid_thread_score =10;