A fix is available
APAR status
Closed as program error.
Error description
DFHXM0004 message stating possible loop in DFHXMAT with only 50K transactions queued.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All CICS users. * **************************************************************** * PROBLEM DESCRIPTION: CICS is receiving 50000 remote * * transaction STARTs into a region. The * * remote started transaction is TCLASSed * * to allow only 1 active at a time. * * DFHXM0004 message and dump are issued * * indicating a possible loop in DFHXMAT. * **************************************************************** When message DFHXM0004 was issued, the CSNC task was running and showed DFHXMAT processing ALLOCATE_NEW_TRANNUM_RANGE. The CICS region had 49936 tasks queuing + 7 active, so there should have been about 50000 free task number slots to use. CICS miscalculated the slot value causing the region to loop looking for a new slot number. When the ICVR limit was hit CICS issued message DFHXM0004 and continued to do so despite there appearing to be no more than 50000 tasks in the system out of the possible 99999. Analysis of the dump shows that trannums are incremented by 2.
Problem conclusion
DFHXMAT has been changed to ensure that the trannums are incremented correctly when allocating a new number
Temporary fix
Comments
APAR Information
APAR number
PH58635
Reported component name
CICS TS Z/OS V6
Reported component ID
5655YA100
Reported release
400
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2023-12-07
Closed date
2024-04-09
Last modified date
2024-05-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI96413
Modules/Macros
DFHXMAT DFHXMXE
Fix information
Fixed component name
CICS TS Z/OS V6
Fixed component ID
5655YA100
Applicable component levels
R400 PSY UI96413
UP24/04/10 P F404
Fix is available
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Document Information
Modified date:
02 May 2024