A fix is available
APAR status
Closed as program error.
Error description
IMS can hang waiting for a CQSMOVE request to complete under the following circumstances: 1. MSGQ structure is in overflow processing and there is no overflow structure. 2. CQSMOVE is issued to move from one queue name to another. (i.e. Dequeuing the suspend queue) 3. The source queue name must have been selected for overflow. 4. The destination queue name must not have been selected for overflow. Due to a problem in CQSMOV00 when completing the move logic, there was no response to IMS for this request. Since this flow would have an indication that there was an active queue manager flow in the system, IMS will hang at the time the next checkpoint is issued.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All V11 IMS users of shared queues and CQS. * **************************************************************** * PROBLEM DESCRIPTION: IMS waits for CQS to complete a move * * request and appears hung during a * * simple checkpoint. * **************************************************************** * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF * **************************************************************** The queue structure is in the overflow mode and no overflow structure is defined. IMS requests CQS to move messages between client queues, such as dequeueing the suspend queue. CQS attempts to move messages from a source queue which has been selected for overflow to a destination queue which has not been selected for overflow. During the move request processing, CQS incorrectly thinks that the source queue is quiesced and decides to stop the move request and not to return a response to IMS. If the queue was quiesced because of the overflow condition, then the move process would stop and resume processing the request when the overflow condition ends. Here the source queue is actually not quiesced, thus CQS should continue completing the IMS's move request. The CQS's move request processing stoppage impacts the IMS checkpoint process. IMS keeps track of the QPOOL count of in-progress operations to determine when to process a checkpoint. If the count is zero indicating there is no tasks in progress, then the checkpoint will proceed. If the count is not zero indicating there are some tasks in progress, then the checkpoint waits until the count becomes zero or no tasks are running. Since the CQS move request task never completes, the count never goes down to zero, the checkpoint goes into the wait state, this holds up all other tasks waiting behind the checkpoint, and IMS hangs. This hang condition happens when a combination of the following is true: . The queue structure must be an overflow mode with no overflow structure. . CQSMOVE is issued to move messages between client queues. . The source queue name must have been selected for overflow. . The destination queue name must not have been selected for overflow.
Problem conclusion
GEN: KEYWORDS: SYSPLEXDS *** END IMS KEYWORDS *** CQSMOV00 - CQSMOVE request processor. In the move-by-queue-name routine OLDQ0000, changed to ensure that when the source queue is not quiesced, the move process should continue to completion.
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PM82570
Reported component name
IMS V11
Reported component ID
5635A0200
Reported release
101
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2013-02-11
Closed date
2013-02-21
Last modified date
2013-04-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
CQSMOV00
Fix information
Fixed component name
IMS V11
Fixed component ID
5635A0200
Applicable component levels
R100 PSY UK91994
UP13/03/05 P F303 ¢
Fix is available
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Document Information
Modified date:
02 April 2013