A fix is available
APAR status
Closed as program error.
Error description
User observes, for MQ SMF the value for maximum DNS duration is not cleared across intervals such that information (e.g. that provided by MQCHIN004S) is repeated even if it is not related to measurements captured during the current interval. Development finds the "longest DNS request" value in MP1B is derived from SMF field QCTLGDU. This field is set from a field in the xGWA when CHINIT statistics is collected in CSQXSMFT. The value is obtained at the same time as clearing the field using a CDSG instruction. Unfortunately, there is a bug in this code which results in the value in the xGWA never being cleared.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM MQ for z/OS Version 9 * * Release 4 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: When SMF statistics are enabled, the * * "Longest DNS request" value of the DNS * * statistics is not reset between * * statistics intervals and is incorrectly * * reported in subsequent intervals. * **************************************************************** Due to an error in the statistics collection logic, the "Longest DNS request" DNS statistics field was being read correctly but not cleared. This caused the value from one interval to persist and be incorrectly reported in all subsequent intervals.
Problem conclusion
The statistics collection logic has been corrected to properly clear the "Longest DNS request" field after reading it.
Temporary fix
Comments
APAR Information
APAR number
PH69352
Reported component name
IBM MQ Z/OS V9
Reported component ID
5655MQ900
Reported release
400
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2025-12-11
Closed date
2026-02-19
Last modified date
2026-05-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UO06865
Modules/Macros
CSQXSMFT
Fix information
Fixed component name
IBM MQ Z/OS V9
Fixed component ID
5655MQ900
Applicable component levels
R400 PSY UO06865
UP26/04/14 P F604
Fix is available
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Document Information
Modified date:
02 May 2026