A fix is available
APAR status
Closed as program error.
Error description
A negative recv() timeout value is being calculated as the interval between the current time and the time that some non-heartbeat data was last received is greater than the configured DISCINT value for client channel. This negative recv() timeout value results in the high CPU in the CHIN.
Local fix
The problem could be circumvented by setting DISCINT to 0 for SVRCONN
Problem summary
**************************************************************** * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 * * Release 1 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: High CPU usage reported in CHIN when * * using SHARECNV>0 SVRCONN channels with * * disconnect interval configured. * **************************************************************** * RECOMMENDATION: * **************************************************************** Client applications executing MQGET with unlimited or very long wait intervals connected using SHARECNV >0 SVRCONN channels with disconnect interval (DISCINT) configured with a value smaller than the MQGET WAIT interval can cause the invocation of TCPIP receive calls with negative timeout values causing the receive to return immediately with a reason code indicating that timeout interval has expired resulting in a loop of receive calls expecting data or a heartbeat message or DISCINT to expire. This loop causes the high CPU usage observed.
Problem conclusion
CSQXCCAX (cciReceiveOne) has been changed to prevent passing negative timeout intervals to the TCP IP receive calls avoiding the loop. 100Y CSQXCCAX
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PI69444
Reported component name
WMQ Z/OS V7
Reported component ID
5655R3600
Reported release
100
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-09-20
Closed date
2016-09-27
Last modified date
2016-12-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI41145
Modules/Macros
CSQXCCAX
Fix information
Fixed component name
WMQ Z/OS V7
Fixed component ID
5655R3600
Applicable component levels
R100 PSY UI41145
UP16/11/26 P F611 ¢
Fix is available
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Document Information
Modified date:
01 December 2016