A fix is available
APAR status
Closed as program error.
Error description
Hursley finds, in an IMS TPIPE environment, symptoms of uncommitted messages looks to be a secondary effect of an unintended tight loop when NACK_TPIPE_STOPPED occurs. . In its re-creation scenario, a flood of CSQ2003E messages is generated, due to a defect that incorrectly performs a shutdown rather than suspending the connection as a response to the NACK_TPIPE_STOPPED
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM MQ for z/OS Version 9 * * Release 0 Modification 0 and Release 1 * * Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: Multiple CSQ2003E messages while a * * TPIPE to IMS is stopped. * **************************************************************** Repeated attempts to send a message on an IMS Bridge queue while the TPIPE is stopped result in multiple CSQ2003E 'OTMA REJECTED MESSAGE - SYSTEM ERROR, SENSE CODE=000F0000' messages. The problem arises when the IMS Bridge queue control task CSQ2QCP0 handles the negative acknowledgment to the send, sense code '000F0000'x NACK_TPIPE_STOPPED. The failing message send is backed out and the message reinstated on the IMS bridge queue, CSQ2QCP0 then ends. However CSQ2QCP0 is subsequently re-started by the IMS Bridge member control task CSQ2MEM0, and attempts to re-send the message on the Bridge queue even though the TPIPE to IMS is still stopped. The send fails again in the same way leading to the reported loop.
Problem conclusion
CSQ2QCP0 has been changed for the reported problem so that it will be suspended rather than stopping when a message send fails because the TPIPE is stopped. While CSQ2QCP0 is suspended no further attempts will be made to send messages on the IMS Bridge queue, preventing the reported loop.
Temporary fix
Comments
APAR Information
APAR number
PH18494
Reported component name
IBM MQ Z/OS V9
Reported component ID
5655MQ900
Reported release
000
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2019-10-24
Closed date
2019-11-12
Last modified date
2019-11-30
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI66375 UI66376
Modules/Macros
CSQ2QCP0
Fix information
Fixed component name
IBM MQ Z/OS V9
Fixed component ID
5655MQ900
Applicable component levels
Fix is available
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Document Information
Modified date:
30 November 2019