Note
For V4.1.0, this parameter is available starting with V4.1.0.
Description
cpu_quota_concurrency specifies the maximum number of active threads allowed per CPU quota for a tenant.
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 | DOUBLE |
| Default value | 4 |
| Value range | [1, 20]
NoteFor V4.2.0, the value range is changed from [1, 10] to [1, 20]. |
| Modifiable | Yes. You can use the ALTER SYSTEM SET statement to modify the parameter.
NoticeDo not modify this parameter. Otherwise, performance may be affected or stability risks may occur if the value is decreased. If the value is increased, memory usage may increase and CPU load may become excessive. Therefore, this parameter is risky to modify. |
| Effective upon OBServer node restart | No. The setting takes effect immediately. |
Considerations
The number of threads that can be processed by a tenant is controlled by the cpu_quota_concurrency and workers_per_cpu_quota parameters. When you set these parameters, make sure that workers_per_cpu_quota > cpu_quota_concurrency, where:
workers_per_cpu_quotaspecifies the maximum number of worker threads that can be allocated on each CPU for a tenant. For more information aboutworkers_per_cpu_quota, see workers_per_cpu_quota.cpu_quota_concurrencyspecifies the maximum number of active threads allowed per CPU quota, that is, the concurrency.
Examples
Set the maximum number of active threads allowed per CPU quota for a tenant to 4.
obclient> ALTER SYSTEM SET cpu_quota_concurrency=4;