Processor Queue Length

The Processor Queue Length is the number of threads that are ready but currently unable to run on the processor due to another active thread.

A bottleneck on the processor may be thought to occur where the number of threads in the queue is more than 2 times the number of processor cores over a continuous period.

To perform this Check, the Agent polls the processor queue every five seconds. Where the number of jobs in the queue exceeds the threshold, times the number of processor cores over the Agent cycle (5 or 15 minutes), we generate an Alert.

The Dashboard displays the average and maximum queue for each processor over the Agent cycle.

Use the Check in conjunction with the Processor Utilization Check and where both indicators exceed the recommended threshold over the same continuous period then this would indicate there is a bottleneck with the processors.

Thresholds

From Dashboard 2020.01.20 we updated the default threshold values for new Checks. Existing Check thresholds are unaffected.

Threshold	Pre-2020.01.2 Threshold	Threshold from 2020.01.2
Alert if average queue length per core >	2 /Core	4 /Core