Monitoring Run queue for AIX in NMON


I need to know about Run Queue in AIX and how to find the bottleneck of Run queue.

what is the threshold value for Run Queue length.

Kindly guide me on this.

Best Answer

VMSTAT r (runqueue) The runqueue value shows the number of tasks executing and waiting for CPU resources. When this number exceeds the number of CPUs on the server, a CPU bottleneck exists, and some tasks are waiting for execution.

I believe in AIX this would be a number equal to or less than lcpu.

The run-queue length means "the sum of the number of processes that are currently running plus the number that are waiting (queued) to run." System configuration: lcpu=16 mem=65536MB ent=4.00

kthr memory page faults cpu

r b avm fre re pi po fr sr cy in sy cs us sy id wa pc ec 7 1 8986596 4079422 0 0 0 1 3 0 1017 16130 8195 0 0 99 0 0.03 0.8

The server above shows run-queue of 7. I have lcpu=16. So it is fine. Anything above 16 would imply there are processes waiting. The higher the number the more the wait, the higher perf issues you will find.

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