A fix is available
APAR status
Closed as program error.
Error description
Experienced S0C4 abends in some of the CHINIT address spaces after setting DEFCLXQ(CHANNEL). . Messages from the CHIN joblog: DUMP TITLE=CSQ1,ABN= 0C4-00000004,C=W9700.xxx.CHIN,M=CSQXDISP, LOC=CSQXRCTL.CSQXRCCC+00xxx +CSQX112E CSQXDISP Dispatcher process error, TCB=xxxxxxxx reason=0C4000-00000004 . Abend is in CSQXRCCC (GA) The 0C4 in CSQXRCCC occurs when using DEFCLXQ and starting a cluster-sender channel (in this case SYSTEM.DEF.CLUSSDR) which is not found in the cluster cache (CSQXRCCC does not obtain an rriSession control block). . Additional keywords: ABEND0C4 ABENDS0C4 S0C4 S00C4 0C4
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: * * All users of IBM MQ for z/OS Version 9 * * Release 0 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: * * Message CSQX112E and ABEND0C4 in csqxrccc after START * * CHANNEL(SYSTEM.DEF.CLUSSDR). * **************************************************************** * RECOMMENDATION: * * None * **************************************************************** The only purpose of the channel definition SYSTEM.DEF.CLUSSDR is to supply default values for other cluster-sender channel definitions. However in the reported problem SYSTEM.DEF.CLUSSDR is STARTed as if it were a valid channel. The START fails with multiple error messages, including CSQX519E which is issued twice. The START is re-tried automatically at intervals, each time failing in the same way. Initially queue manager attribute DEFCLXQ is left to default to SCTQ such that all cluster-sender channels use the default transmission queue SYSTEM.CLUSTER.TRANSMIT.QUEUE. However after a period DEFCLXQ is changed to CHANNEL which causes each cluster-sender channel to use it's own unique transmission queue. The next time the channel START is re-tried an attempt is made to update the rriSession control block to set flag rriSO_XMITQ_SWITCH_PENDING, to indicate that the transmission queue is to be changed. As part of this START processing module csqxrccc attempts to locate the channel SYSTEM.DEF.CLUSSDR, looking first in the cache where it is not found, and then in the channel table where it is located. In this specific case the code takes a path that fails to setup pSess, the pointer to the rriSession. Consequently the attempt to set rriSO_XMITQ_SWITCH_PENDING fails with the reported ABEND0C4 and message CSQX112E. Previously when DEFCLXQ defaulted to SCTQ, csqxrccc also failed to setup pSess, but there was no attempt to update the rriSession control block so there was no ABEND. The null pSess was subsequently detected by the code resulting in the second CSQX519E message.
Problem conclusion
Module csqxrccc has been updated for the reported problem to ensure that an rriSession is allocated during START processing for a cluster-sender channel that is found in the channel table but not in the cache.
Temporary fix
Comments
APAR Information
APAR number
PI69622
Reported component name
MQ Z/OS V9
Reported component ID
5655MQ900
Reported release
000
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-09-22
Closed date
2016-10-13
Last modified date
2017-02-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI41632
Modules/Macros
CSQXRCCC
Fix information
Fixed component name
MQ Z/OS V9
Fixed component ID
5655MQ900
Applicable component levels
R000 PSY UI41632
UP17/01/10 P F701
Fix is available
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Document Information
Modified date:
01 February 2017