A fix is available
APAR status
Closed as program error.
Error description
*CSQV086E +CSQ1 QUEUE MANAGER ABNORMAL TERMINATION REASON=00940001 IEA794I SVC DUMP HAS CAPTURED: DUMPID=nnn REQUESTED BY JOB (xxxxxxxx) DUMP TITLE=CSQ1,ABN=5C6-00940001,U=uuuuuuuu,C=MQ900.900.CMC -CS QMCPRH,M=CSQGFRCV,LOC=CSQMCGLM.CSQMCPRH+000032B8 IEF450I CSQ1MSTR CSQ1MSTR - ABEND=S6C6 U0000 REASON=00940001 An IMS connection was processing a close_all_handles request (part of disconnect processing). The abend occurred because at completion of this call MQ detects that an internal latch remains held. This is an unexpected situation as the latches are a short-term serialization mechanism which should not be retained across API calls. There is a timing window where one MQ task can delete a control block which still needs to be referenced by an IMS task. If the deletion occurs, then it is possible for the control block to be allocated to another task and the fields updated before the IMS task is able to finish using it. This can result in the latch-held flag being left on for the IMS task. The point in the code where this could occur is only a few instructions long, so it would be rare for the two tasks to be processing in a way which would cause the issue. Additional Symptom(s) Search Keyword(s): ABENDS5C6 S5C6 S05C6 00940001
Local fix
A ++APAR is available from the support center. . Another option is to turn off SMF 116 CLASS(3) data. Be aware this controls thread and queue level accounting information. Consider carefully your use of the data before deciding whether to turn it off using the MQ command: STOP TRACE(ACCTG) DEST(SMF) CLASS(03)
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM MQ for z/OS Version 9 * * Release 0 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: Abend S5C6-00940001 occurs in CSQMCPRH * * when an IMS BMP or transaction ends, * * and class 3 accounting is turned on. * * The abend is followed by abnormal * * queue manager termination 6C6 with * * REASON=00940001 * **************************************************************** CSQ7COLL was called for a close_all_handles request to collect accounting information for the terminating IMS transaction. After collecting the information, the WQELI for the transaction was added to the chain of WQELI's for deallocation processing, and the WQELI latch was released. However, between the WQELI being added to the chain, and the latch being released CSQ7PLRT was resumed by another task and processed the deallocation chain, leading to the WQELI being freed. When the latch release took place, the WQELI had been reused, and so it appeared that the latch was not held. However the EB for the task still indicated a latch was held. When CSQMCPRH later checked for unreleased latches, it detected that the EB still held a latch - this is unexpected, and led to the reported abend and queue manager termination.
Problem conclusion
CSQ7COLL is changed to release the latch prior to chaining the WQELI on to the deallocation chain.
Temporary fix
Comments
APAR Information
APAR number
PI87591
Reported component name
MQ Z/OS V9
Reported component ID
5655MQ900
Reported release
000
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-09-19
Closed date
2017-10-20
Last modified date
2017-12-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI51299
Modules/Macros
CSQ7COLL CSQ7PLRT
Fix information
Fixed component name
MQ Z/OS V9
Fixed component ID
5655MQ900
Applicable component levels
R000 PSY UI51299
UP17/11/21 P F711 ¢
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
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Document Information
Modified date:
02 December 2017