Note
This parameter was introduced in V4.3.4.
Description
The sync_io_thread_count parameter specifies the number of threads for synchronous I/O requests. By default, the parameter is adaptively configured. This configuration can fully utilize the bandwidth of synchronous I/O devices. When the latency of synchronous I/O requests is too high, you can increase the value of this parameter.
Privilege requirements
Query the parameter
The
systenant and all user tenants can use theSHOW PARAMETERSstatement or theGV$OB_PARAMETERSview to query this parameter.Modify the parameter
Only the
systenant can modify this parameter. User tenants cannot modify this parameter.
Attributes
| Attribute | Description |
|---|---|
| Type | Int |
| Default value | 0 |
| Value range | [0,1024] |
| Modifiable | Yes. You can execute the ALTER SYSTEM SET statement to modify this parameter. |
| Effective upon OBServer node restart | No. The parameter takes effect immediately after it is set. |
Considerations
If the value of this parameter is 0, the following rules apply:
If the number of CPU cores is less than or equal to 16,
thread_count = CPU core count * 6If the number of CPU cores is greater than 16,
thread_count = 16 * 6 + (CPU core count - 16) * 2
Example
Set the number of threads for synchronous I/O requests to 200.
obclient> ALTER SYSTEM SET sync_io_thread_count = 200;