MUTEXLCKALERT, Mutual Exclusion subsystem ALERT - Lock attempt threshold crossed for region rrrr. Process pppp is in crit cycle cccc.

Run Time Error: This warning indicates that a process could not obtain a critical section lock for region rrrr even after waiting longer than the GT.M determined threshold (approximately 45 seconds) because the critical section lock was held that entire time by another process pppp. cccc is the crit cycle count which GT.M increases by one every time it successfully grants the mutual exclusion (mutex) lock to a process. cccc provides a measure of the frequency of mutex lock use. MUTEXLCKALERT messages indicate that process pppp is blocking access to region rrrr for inappropriately long periods of time and thereby impacting performance for other processes needing access that region.

GT.M produces this warning when:

Action: Monitor the system to determine whether there is a process with process id pppp and whether that process is a GT.M process.

Implement a script to get a stack trace for process pppp or take other appropriate action and use the $gtm_procstuckexec environment variable to activate it before the block process sends the MUTEXLCKALERT message.

Identify and terminate process pppp to release control of that resource. If the process is a GT.M process, use a MUPIP STOP to terminate it. If a process of another application, use an appropriate mechanism to stop it.

If this message is due to an IO bottleneck, adopt a strategy that reduces IO. Some of the IO reducing strategies are:


Do not apply IO reduction strategies all at once. Try them one at a time and always verify/measure the results of each strategy.

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