APAR status
Closed as program error.
Error description
Queue manager generated failure data capture (FDC) records with error xecL_W_LONG_LOCK_WAIT in different MQAPI calls when processing messages from deep queues and delays observed in MQAPI calls. MQ trace shows that some threads are not getting the lock as expected which caused the LONG_LOCK_WAIT FDCs. Probe Id :- XC307100 Component :- xlsRequestMutex Program Name :- amqzlaa0 Major Errorcode :- xecL_W_LONG_LOCK_WAIT Probe Description :- AMQ6150: WebSphere MQ semaphore is busy. MQM Function Stack zlaMainThread zlaProcessMessage zlaProcessMQIRequest zlaMQPUT zsqMQPUT kpiMQPUT kqiPutIt kqiPutMsgSegments kqiTickleEarly apiLockExclusive xlsRequestMutex xcsFFST Probe Id :- XC307100 Component :- xlsRequestMutex Program Name :- amqzlaa0 Major Errorcode :- xecL_W_LONG_LOCK_WAIT Probe Description :- AMQ6150: WebSphere MQ semaphore is busy. MQM Function Stack zlaMainThread zlaProcessMessage zlaProcessMQIRequest zlaMQCMIT zsqMQCMIT kpiSyncPoint apiSyncPoint atmSyncPoint atxCommit atxPerformCommit aqmSyncPoint aocLockQHandle xlsRequestMutex xcsFFST Probe Id :- XC308010 Component :- xlsReleaseMutex Program Name :- amqzlaa0 Major Errorcode :- xecL_W_LONG_LOCK_WAIT Probe Description :- AMQ6150: WebSphere MQ semaphore is busy. MQM Function Stack zlaMainThread zlaProcessMessage zlaProcessMQIRequest zlaMQGET zsqMQGET kpiMQGET kqiWaitForMessage apiUnlockExclusive xlsReleaseMutex xcsFFST
Local fix
Problem summary
**************************************************************** USERS AFFECTED: Users consuming messages from deep queues and/or on busy systems Platforms affected: MultiPlatform **************************************************************** PROBLEM DESCRIPTION: This problem occurred because IBM MQ did not give higher priority to MQ SRAs(threads) which were waiting for a long time.
Problem conclusion
IBM MQ code has been modified to allow the priority of the SRAs which are waiting for a long time to be tuned if it is deemed necessary by IBM support. As the need for this tuning is deemed unlikely for the majority of workloads, the default product behaviour is unchanged. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: Version Maintenance Level v8.0 8.0.0.8 v9.0 CD 9.0.5 v9.0 LTS 9.0.0.3 The latest available maintenance can be obtained from 'WebSphere MQ Recommended Fixes' http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037 If the maintenance level is not yet available information on its planned availability can be found in 'WebSphere MQ Planned Maintenance Release Dates' http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309 ---------------------------------------------------------------
Temporary fix
Comments
APAR Information
APAR number
IT20464
Reported component name
WMQ BASE MULTIP
Reported component ID
5724H7251
Reported release
800
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-05-04
Closed date
2017-10-20
Last modified date
2017-10-25
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
WMQ BASE MULTIP
Fixed component ID
5724H7251
Applicable component levels
R800 PSY
UP
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Document Information
Modified date:
25 October 2017