APAR status
Closed as program error.
Error description
An application removes a message that is under a browse cursor that is being kept for the same HObj or another HObj. That HObj is then used in a call to MQGET with MQGMO_BROWSE_NEXT. The MQGET takes a long time to return, if the queue is deep. If the return from MQGET is 2033 MQRC_NO_MSG_AVAILABLE then the next MQGET is also slow. This is most visible if the queue is deep, and the message that was removed is near the end of that queue. Trace shows that MQ iterates through each message on the queue every time a queue BROWSE_NEXT is called. This issue can be created by browsing the last message on the queue, consuming it, and then continuing to browse. Each browse will iterate through every message on the queue until we hit the end of the queue and return 2033.
Local fix
Problem summary
**************************************************************** USERS AFFECTED: Users who concurrently browse and consume MQ messages using the same HObj (object handle) or a different HObj. Platforms affected: MultiPlatform **************************************************************** PROBLEM DESCRIPTION: The problem was caused by a combination of internal flags that is set when a message is destructively consumed. These flags caused IBM MQ to iterate through every message on the queue each time that MQGET is called with MQGMO_BROWSE_NEXT.
Problem conclusion
A new internal flag has been introduced which will allow IBM MQ to continue browsing from the point in the browse list where a message was last destructively consumed. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: Version Maintenance Level v7.1 7.1.0.9 v7.5 7.5.0.8 v8.0 8.0.0.5 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
IT16182
Reported component name
WMQ BASE MULTIP
Reported component ID
5724H7241
Reported release
750
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-07-18
Closed date
2016-09-22
Last modified date
2017-11-21
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
5724H7241
Applicable component levels
[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSFKSJ","label":"WebSphere MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Line of Business":{"code":"LOB45","label":"Automation"}}]
Document Information
Modified date:
14 December 2020