APAR status
Closed as program error.
Error description
MQ could potentially incorrectly reset the the MQ transaction log LSN to zero resulting in a log sequence number outside the expected range. In this state, the next time the queue manager was ended, it could not be started. An FFST with the following notable characteristics is generated: | Probe Id :- HL008001 | Component :- hlgSetLogRestartLsn | Program Name :- amqzmuc0 | Major Errorcode :- xecF_E_INVALID_PARAMETER_VALUE MQM Function Stack zmuThreadMain zmuCheckpointTask alsCheckPointLoop aocPerformCheckpoint atmSetOldestTranLSN almSetOldestTranLSN hlgSetLogRestartLsn xcsFFST Within the FFST data, the dbcb structure also contains the lowtranlsn of 0: lowtranlsn: <0:0:0:0> 0X0000000000000000
Local fix
Problem summary
**************************************************************** USERS AFFECTED: IBM MQ installations on modern processors utilising instruction re-ordering optimisations. One known example of a processor family which is capable of such instruction re-ordering is the POWER family in an AIX environment. Platforms affected: MultiPlatform **************************************************************** PROBLEM DESCRIPTION: Instruction re-ordering on modern processors could lead to internal state flags being set in an unexpected order and resulting in an incorrect code path to be followed and corruption of the LSN values.
Problem conclusion
The MQ code had been resolved to ensure the code path execution is synchronised with the processor instruction caches to avoid the flags being set incorrectly. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: Version Maintenance Level v7.5 7.5.0.9 v8.0 8.0.0.9 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
IJ02451
Reported component name
WMQ AIX V7
Reported component ID
5724H7221
Reported release
710
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-12-06
Closed date
2018-01-22
Last modified date
2018-03-12
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 AIX V7
Fixed component ID
5724H7221
Applicable component levels
R710 PSY
UP
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSFKSJ","label":"WebSphere MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.1"}]
Document Information
Modified date:
09 March 2021