Note
The effective scope of this parameter has been changed to the tenant level since OceanBase Database V4.1.0.
Description
The cpu_quota_concurrency parameter specifies the maximum concurrency allowed for each CPU quota of a tenant.
Attributes
| Attribute | Description |
|---|---|
| Type | Double |
| Default value | 4 |
| Value range | [1, 20]
NoteThe value range of this parameter has been changed from [1, 10] to [1, 20] since OceanBase Database V4.2.0. |
| Modifiable | Yes. You can use the ALTER SYSTEM SET statement to modify the parameter.
NoticeWe recommend that you do not modify this parameter. If you decrease the value of this parameter, performance and even stability may be affected. If you increase the value of this parameter, memory usage and CPU utilization may increase. |
| Effective upon OBServer node restart | No |
Considerations
The number of threads that can be concurrently handled by a tenant is controlled by two parameters: cpu_quota_concurrency and workers_per_cpu_quota. The two parameters must meet the following condition: workers_per_cpu_quota > cpu_quota_concurrency.
workers_per_cpu_quotaspecifies the maximum number of worker threads that a tenant can allocate to each CPU. For more information aboutworkers_per_cpu_quota, see workers_per_cpu_quota.cpu_quota_concurrencyspecifies the number of active worker threads of the tenant on each CPU, that is, the number of concurrent worker threads.
Example
obclient> ALTER SYSTEM SET cpu_quota_concurrency=4;