A fix is available
APAR status
Closed as program error.
Error description
During a CICS SOS, module DFHAPCR +x'9D6' takes multiple 0C4 abends. The SOS occurred after a flood of pipeline transactions started. Here are corresponding error messages: +DFHSM0142 CICS is still under stress (short on storage above 16MB). +DFHSM0002 A severe error (code X'0315') has occurred in module DFHSMGF. +DFHAP0001 An abend (code 0C4/AKEA) has occurred at offset X'09D6' in module DFHAPCR. The 0C4s occur after a task suspends during a GETMAIN request from DFHAPCR, trying to obtain a channel buffer. The task is eventually purged, however DFHAPCR does not check the response but instead proceeds as if the GETMAIN was successful. The 0C4s occur because the address of the buffer is not valid. After the 0C4s in DFHAPCR, some tasks may loop in DFHRMRS and eventually get abended as runaway, message DFHRM0001 abend AKEC. The DFHRM0001 AKECs seem to be due to residual data following the 0C4s in DFHAPCR. Additional Symptom(s) Search Keyword(s): EXPORT_ALL dfhapcr_obtain_channel_buffer CHANBUFF CheckIterators abend0C4 S0C4 abend S0C4 DFHSM0133 CICS is under stress (short on storage above 16MB) DFHSM0134 CICS is no longer short on storage above 16MB DFHSM0002 A severe error (code X'0305') has occurred in module DFHSMGF. You see the following exception trace entries: SM 1002 SMSQ EXIT - FUNCTION(SUSPEND_REQUEST) RESPONSE(PURGED) REASON(INSUFFICIENT_STORAGE) SM 0302 SMGF EXIT - FUNCTION(GETMAIN) RESPONSE(PURGED) REASON(INSUFFICIENT_STORAGE) ADDRESS(0011B0E9) Even though the getmain was not successful, the code continues as if it was successful, using a residual address above. In this case the address belonged to another task, so CICS moved data into this area causing storage violations as well as CICS areas like QPH's getting overlaid. The next trace following the purge was: PG 1900 PGCR ENTRY - FUNCTION(GET_CONTAINER_INTO) CONTAINER_TOKEN(1F59A2D0) CALLER(SYSTEM) CONVERT(NO) ITEM_BUFFER(0011B418 ,00000000 , 0011B1DA) DFHSM0102 INVALID QPH
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All CICS users. * **************************************************************** * PROBLEM DESCRIPTION: Abend S0C4 in DFHAPCR during a short on * * storage in CICS. * **************************************************************** CICS is acting as a Web Services provider and, during a workload spike, goes in and out of SOS. Module DFHAPCR's EXPORT_ALL issues a getmain while CICS is SOS and suspends, waiting for storage to become available. After a while, the task is purged. DFHAPCR's GETMAIN procedure regains control, with a response of SMGF_PURGED, but continues as though an exception hadn't occurred. When DFHAPCR tries to initialise the storage, it suffers an 0C4 abend because it has a null pointer.
Problem conclusion
DFHAPCR, DFHPIIS and DFHPISN have been changed to act on the purged response rather than trying to access storage using a null pointer and percolating the response. DFHRZST has been changed to prevent a short on storage situation caused by the DFHAPCR IMPORT_ALL code trying to receive an 8 byte channel header and only getting the 4 byte trailer.
Temporary fix
Comments
APAR Information
APAR number
PH39877
Reported component name
CICS TS Z/OS V5
Reported component ID
5655Y0400
Reported release
200
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2021-08-16
Closed date
2022-01-20
Last modified date
2023-02-07
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
DFHAPCR DFHPIA1 DFHPIAD DFHPIAT DFHPICA DFHPICC DFHPIDM DFHPIDSH DFHPIDUF DFHPIII DFHPIIW DFHPIJG DFHPIJP DFHPIJP1 DFHPIJS DFHPIJW DFHPILN DFHPIMM DFHPIPL DFHPIPM DFHPIPM2 DFHPIPS DFHPIRE DFHPIRI DFHPIRL DFHPIRM DFHPIRN DFHPIRS DFHPISC DFHPISF DFHPISN DFHPIST DFHPITC DFHPITC1 DFHPITC2 DFHPITC3 DFHPITE DFHPITH DFHPITJ DFHPITL DFHPITQ DFHPITRI DFHPITS DFHPIUE DFHPIWR DFHPIWT DFHPIXI DFHPIXM DFHPIXO DFHRZTA DFHWSADH DFHWSATR DFHWSATX DFHXCSCR
Fix information
Fixed component name
CICS TS Z/OS V5
Fixed component ID
5655Y0400
Applicable component levels
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.
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSGMGV","label":"CICS Transaction Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.5","Line of Business":{"code":"LOB35","label":"Mainframe SW"}}]
Document Information
Modified date:
08 February 2023