Summary information |
|
|---|---|
Default value |
2000 |
Range of values |
0–2147483647 |
Status |
Dynamic |
Display level |
Comprehensive |
Required role |
System Administrator |
runnable process search count specifies the number of times an engine loops while looking for a runnable task before relinquishing the CPU to the operating system.
Adaptive Server engines check the run queue for runnable tasks whenever a task completes or exceeds its allotted time on the engine. At times, there will not be any tasks in the run queues. An engine can either relinquish the CPU to the operating system or continue to check for a task to run. Setting runnable process search count higher causes the engine to loop more times, thus holding the CPU for a longer time. Setting the runnable process search count lower causes the engine to release the CPU sooner.
If your machine is a uniprocessor that depends on helper threads to perform I/O, you may see some performance benefit from setting runnable process search order to perform network I/O, disk I/O, or other operating system tasks. If a client, such as a bulk copy operation, is running on the same machine as a single CPU server that uses helper threads, it can be especially important to allow both the server and the client access to the CPU.
If you are having performance problems, try setting runnable
process search count to 3.
For Adaptive Servers running on uniprocessor machines that do not use helper threads, and for multiprocessor machines, the default value provides good performance.
Use sp_sysmon to determine how the runnable process search count parameter affects Adaptive Server’s use of CPU cycles, engine yields to the operating system, and blocking network checks. See the Performance and Tuning Guide for information.
