Note
This parameter is available starting from V4.3.5 BP2.
Description
io_scheduler_thread_count specifies the number of threads for I/O isolation scheduling logic.
Privilege requirements
Query the parameter
systenant and all user tenants can query this parameter by using theSHOW PARAMETERSstatement or theGV$OB_PARAMETERSview.Modify the parameter
Only the
systenant can modify this parameter. User tenants cannot modify this parameter.
Attributes
Attribute |
Description |
|---|---|
| Type | Int |
| Default value | 4 |
| Value range | [1, 16] |
| Modifiable | Yes. You can use the ALTER SYSTEM SET statement to modify the parameter. |
| Effective upon OBServer node restart | Yes. The setting takes effect after an OBServer restart. |
Usage notes
This parameter dynamically adjusts the number of threads for I/O isolation scheduling logic. You can flexibly adjust resource allocation based on specific business requirements to optimize performance.
Under normal conditions, one thread can support approximately 100,000 IOPS. If the disk performance is good and can reach 400,000 IOPS, it is recommended to set the thread count to 4. In actual online environments, it is recommended to determine the optimal thread count through performance testing.
Examples
Set the number of I/O isolation scheduling threads to 8.
obclient> ALTER SYSTEM SET io_scheduler_thread_count = 8;