A fix is available
APAR status
Closed as program error.
Error description
After an attempt to set an IPCON out of service with CEMT, the CEMT task and the tasks running over the IPCON hang. . In the Lock Manager (LM) domain, in the section ==LM: LOCK WAIT QUEUE the CEMT task's KE_TASK number is listed in the KE_TASK OWNER column for the IPCONN_LOCK of the session being set out of service by CEMT. . KE_TASK LOCK ADDRESS -> NEXT OWNER MODE SUSPEND NAME TOKEN ---- ------- ------- ----- ---- ------- IPCONN_LOCK <ipconn> 2B2731C8 2B273178 SHAR 039F0001 ... 2B2731DC 2B27318C SHAR 03A10001 2B27318C 00000000 2CCD4700 EXCL 03990001 . where 2CCD4700 is the KE_TASK value for the CEMT task. . NOTE: The KE_TASK OWNER column does NOT mean that CEMT is the owner of the lock. It means that it WANTS to become the exclusive owner. Other tasks are waiting for a SHARe of the lock. . At the same time, one of the user tasks is also waiting for an exclusive lock on the IS_LOCK ISCBCHN lock with other tasks waiting for a SHARed of that lock: . IS_LOCK ISCBCHN 2B2741E0 2B2741CC SHAR 064F0001 ... 2B273150 2B27322C SHAR 00730005 2B27322C 00000000 2D1C2700 EXCL 04050001 . These two tasks deadlock, waiting for their respective locks. They may not deadlock directly with each other. But, the tasks waiting for a share of the locks hold other resources. And, those resources are needed by tasks that are waiting behind these two exclusive owners. That causes the deadlock. . CEMT needs to be able to put an IPCONN out of service even when it is being used, with out getting stuck in a lock wait.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All CICS Users * **************************************************************** * PROBLEM DESCRIPTION: When there aren't enough sessions to * * cope with the work to remote * * system, the tasks queueing for * * available session won't free the * * shared lock on ISCB before they * * suspend.If CEMT SET IPCONN OUTSERV * * is issued at this time,CEMT task * * will hang. * **************************************************************** * RECOMMENDATION: * **************************************************************** The tasks that are running do a lot of work to remote systems and there aren't enough sessions to cope with them all running at once. At this time set the IPCONN out of service in CEMT before setting it to RELeased. CEMT hung because it tried to obtain the exclusive lock on ISCB. Unfortunately this ISCB is share-locked by several workload tasks queueing for available sessions. The correct order of execution is the IPCONN has to be in RELEASED state before it can be set OUTSERV otherwise an INVREQ should be returned.
Problem conclusion
A check (whether or not the SERVSTATUS can be changed) has been added before CEMT attempts to obtain the EXCLUSIVE lock in DFHISIC. The SET IPCONN OUTSERV will return with an servstatus_error if the IPCONN is not RELeased.
Temporary fix
FIX AVAILABLE BY PTF ONLY
Comments
APAR Information
APAR number
PM56081
Reported component name
CICS TS Z/OS V4
Reported component ID
5655S9700
Reported release
600
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2012-01-16
Closed date
2012-03-29
Last modified date
2012-05-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK77489
Modules/Macros
DESISIC DFHISIC
Fix information
Fixed component name
CICS TS Z/OS V4
Fixed component ID
5655S9700
Applicable component levels
R600 PSY UK77489
UP12/04/11 P F204
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 May 2012