Cluster reports "High CPU load detected" (PACEMAKER)

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Environment

SUSE Linux Enterprise High Availability Extension 12

SUSE Linux Enterprise High Availability Extension 15

Situation

Sometimes the logs show entries like

crmd[2258]: notice: throttle_check_thresholds: High CPU load detected

crmd[2257]: notice: High CPU load detected

and it appears unclear how to interpret this.

Resolution

These entries can be found on SLE 12 and later Pacemaker Clusters.

These do not use the static

lrmd_max_children

setting anymore, but have a dynamic handling of load.

To detect the system load the crmd queries its own cib and measures the time.

And according to this time will then decrease or increase the maximum number of lrmd processes that can be run in parallel.

Cause

These messages indicate that the cluster will react a little slower, as less lrmd children will be spawned. This will only be noticable on clusters with a lot of primitives.

Also the OS system load is high at this moment. This might indicate that other issues are affecting the OS at this moment, maybe some application or exterior event.

In no case this message is an indication that there is a problem with the cluster. It is an indication that the cluster is reporting a high OS Load.

Disclaimer

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