Fixes are available
APAR status
Closed as program error.
Error description
If a transaction fails immediately after reserving a restart point in the recovery log then it is possible that the only reference to the transaction is in a checkpoint. If the queue manager fails with a transaction in this state then it is possible that the subsequent restart will fail. This is a very small timing window and is very unlikely to match subsequent restart problems. Analysing a problem at this level is very complex and if a reasonable suspicion of a match occurs then L3 should be involved. The sequence of probes HL008001, AL020000, AT013009, KN002003 at queue manager restart would indicate a potential duplicate of this problem (which should then be verified by L3). If the queue manager logs are dumped then the oldest transaction will be seen to have a non-null FirstLSN (matching the LSN in the HL008001 FDC), but a null LastLSN.
Local fix
Problem summary
**************************************************************** USERS AFFECTED: The most likely cause of this problem is that a shortage of disk space causes an in-tran MQPUT to fail. IY79906 should also be considered in these circumstances, as that resolves a checkpoint issue related to disk space issues. Platforms affected: All Distributed (iSeries, all Unix and Windows) **************************************************************** PROBLEM SUMMARY: It is possible for a transaction to be referenced in a checkpoint, even though that transaction has never written a log record. If the transaction then ends without ever writing a log record it is important that the end of the transaction is recorded in the log, in case restart recovers the original reference and then does not realize the transaction ended. The check as to whether to write the end of the transaction log record was based only upon whether the transaction had written a log record and did not take into account that the transaction might have been referenced in a checkpoint without ever actually writing a log record (a very rare occurrence).
Problem conclusion
The decision as to whether the end transaction is recorded in the log is now based upon whether the transaction wrote a log record, or was referenced in a checkpoint. The number of instances where one occurs without the other is so small as to be of no consideration from a performance standpoint. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: v6.0 Platform Fix Pack 6.0.2.3 -------- -------------------- Windows U200279 AIX U811346 HP-UX (PA-RISC) U811630 HP-UX (Itanium) U811631 Solaris (SPARC) U811632 Solaris (x86-64) U811633 iSeries SI27288 Linux (x86) U811634 Linux (x86-64) U811635 Linux (zSeries) U811636 Linux (Power) U811637 Linux (s390x) U811638 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
IZ01794
Reported component name
WMQ LIN X86 V6
Reported component ID
5724H7204
Reported release
600
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2007-07-23
Closed date
2007-07-30
Last modified date
2007-09-04
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 LIN X86 V6
Fixed component ID
5724H7204
Applicable component levels
R600 PSY
UP
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Document Information
Modified date:
31 March 2023