A fix is available
APAR status
Closed as program error.
Error description
CICS region is flooded with CESC transactions. The internal trace a dump shows a sequence of events where IC starts a CESC transaction to process terminal signoff, and another ICE is created for CESC a minute out (safety net). After processing terminals the safety net is canceled but another ICE is created for another run several minutes out. This would be a totally normal operation, if it weren't for that fact that there are 109-110 ICE for CESC currently, such that every 6 minutes, CESC runs 100+ times. . Investigation of how multiple ICEs for CESC were added to the queue, when there should be only one with REQID=DFHCESC, revealed an issue with a timing window. If an ICE was created in a previous run of CICS and preserved over the START=AUTO there is a timing window, when the TCTV_CESC_SCHEDULED flag is OFF during restart, that allows an additional ICE to be created. . Additional Symptom(s) Search Keyword(s): KIXREVSVR
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All CICS Users * **************************************************************** * PROBLEM DESCRIPTION: The ICE chain contains many ICEs with * * REQID=DFHCESC and the CICS region * * is periodically flooded with CESC * * transactions being attached. * **************************************************************** A CICS region was periodically being flooded with CESC transactions. A dump showed there were over a hundred ICEs on the ICE chain with REQID=DFHCESC whereas there should be no more than one. ICEs are restored over a warm restart of CICS but the TCTV_CESC_SCHEDULED flag is initialized to OFF. If an event occurs to cause the rescheduling of CESC before a recovered REQID=DFHCESC ICE has expired, the setting of the TCTV_CESC_SCHEDULED flag causes the cancelling of the recovered ICE to be bypassed in module DFHSNSC.
Problem conclusion
CICS is changed so that ICEs for transaction CESC are not restored over a warm restart. When scheduling CESC in DFHSNSC a DFHIC TYPE=CANCEL is now always attempted for a REQID=DFHCESC ICE, regardless of the setting of TCTV_CESC_SCHEDULED. A response that the ICE was not found is treated as acceptable.
Temporary fix
Comments
APAR Information
APAR number
PH03982
Reported component name
CICS TS Z/OS V5
Reported component ID
5655Y0400
Reported release
100
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2018-10-11
Closed date
2019-01-15
Last modified date
2019-02-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI60693 UI60694 PH33375
Modules/Macros
DFHICRC DFHSNSC
Fix information
Fixed component name
CICS TS Z/OS V5
Fixed component ID
5655Y0400
Applicable component levels
Fix is available
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Document Information
Modified date:
15 January 2021