Note
This parameter is available starting with V4.0.0.
Description
ha_mid_thread_score specifies the current number of working threads for medium-priority high-availability threads.
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 and restore, are scheduled and executed by the tenant-level DagScheduler. Considering the limited thread resources of each tenant, parameters are no longer differentiated by task type. Instead, 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 concurrent threads used by the high-priority HA task queue, such as replication, rebuild, and recovery.ha_mid_thread_score: specifies the number of concurrent threads used by the medium-priority HA task queue, such as migration.ha_low_thread_score: specifies the number of concurrent threads used by the low-priority HA task queue, such as backup, backup of backup, and backup cleanup.
Examples
Set the current number of working threads for medium-priority high-availability threads of the current tenant to 10.
obclient> ALTER SYSTEM SET ha_mid_thread_score =10;