A fix is available
APAR status
Closed as program error.
Error description
A MAS stayed up for several months. Then, without previous errors, it got: . EYUCL0105E ESSS Receive Link Task terminated abnormally. EYUNL0905E An unrecoverable error has occurred. The MAS agent is being terminated. EYUXZ0910I EYU0XZSD Dump ... LMAS,COI0,0000079,TRAC,EYU0NLSD... EYUCL0005I ESSS Receive Link Task terminated. . The MAS agent does come back up automatically. . Two trace entries that were taken for the error: . Task:79 ... Method:CTES Prior:CLEV Debug:EXCEPT Point-Id:8 Major-Obj:COM Envrn:LMAS Type:EXCEPTION Tran_Id:COI0 CICS-Task:COM CMAS: Keyword Data Queue Req Data Data Value Type Dir Opt Address Value In: *FUNCTION FUN . 1D2A0C28 ENDSINK Out: *RESPONSE RSP . 1D2A0C2A EXCEPTION *REASON RSN . 1D2A0C2B METHOD_FAILED . Task:79 Method:CLEV Prior:XLOP Debug:EXCEPT Point-Id:3 Major-Obj:COM Envrn:LMAS Type:EXCEPTION Tran_Id:COI0 CICS-Task:COM CMAS: Keyword Data Queue Req Data Data Value Type Dir Opt Address Value In: *FUNCTION FUN . 1D2A1D23 MASRLT Out: *RESPONSE RSP . 1D2A1D25 00 *REASON RSN . 1D2A1D26 00 . Exception Point-ID number 8 in module DFH0CTES happens in label CTES_PCKT_TYPE: . *-----------------------------------------------------------* * Format MALRL Element and add to the MALRL List * *-----------------------------------------------------------* ... EYUQXCLA CLEAR, ... FUNCTION(ADDCLST), DEBUG('CTESXCLA'), ELEMENT(#WRK_MALRL,CMRL_SIZE,*), LIST_ID(TRNSPT_MASRL), ... LA R4,CMPI_XCPT_XCLA Cache List Add Exception . This is the method that failed. It failed because the transmision counter in the CMAS overflowed and restarted from 0. This counter is used to build the key for MAxRL elements. If it overflows and restarts, then we risk it not being unique. EYUQXCLA failed with a duplicate key status . The transmision counter overflowed because both the CMAS and the MAS had been running continuously and were connected to each other for over five months. The wrapping will only be a problem for a request that would stay around for the life of the MAS. There is one such request - the request to start the heartbeat task (method EYU0NLHD running under a COIE task). This APAR is being taken to investigate whether we can do something about that and eliminate the problem when a wrap occurs. Additional Symptom(s) Search Keyword(s): KIXREVRBD
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All CICSPlex SM V4R1M0 Users * **************************************************************** * PROBLEM DESCRIPTION: If a MAS has been connected to a CMAS * * for a long period of time (generally a * * number of months), the MAS agent may * * terminate with messages EYUCL0105E and * * EYUNL0905E: * * * * EYUCL0105E ESSS Receive Link Task * * terminated abnormally. * * * * EYUNL0905E An unrecoverable error has * * occurred. The MAS agent * * is being terminated. * * * * After the messages are issued, a dump * * will be taken. The title of the dump * * will be similar to the following: * * * * EYU0XZSD Dump,jobname,masname,lpar, * * LMAS,COI0,tasknum,TRAC, * * EYU0NLSD,mm/dd/yy,hh:mm:ss * * * * Examination of the MAS's trace records, * * either in the auxtrace datasets or the * * dump, will show the following exception * * trace entries from the time of the * * messages: * * * * Method TPID Debug text * * ------ ---- ---------- * * CTES 8 EXCEPT * * CLEV 3 EXCEPT * **************************************************************** * RECOMMENDATION: After applying the PTF that resolves this * * APAR, all MASes must be restarted. Note * * that the restarts do not need to occur at * * the same time. * **************************************************************** When a CMAS sends a request to a MAS, method EYU0CTES (CTES) running in the MAS, places an element in its MAS response list (CMRL) for the request. The element will be removed from the CMRL when the request ends. The key for the list element, called the packet set ID (PSID), is the four byte SYSIDNT of the CMAS followed by a four byte numeric field. The numeric field is a counter maintained by the CMAS. It starts with a value of one (1), and is incremented by one (1) for each request the CMAS sends. When the counter reaches 2,147,483,647, it will wrap to zero (0) for the next request, and continue to be incremented for subsequent requests. When a MAS starts, the CMAS sends a request to the MAS to start the hearbeat task (method EYU0NLHD (NLHD) running under transaction COIE). Since this task runs for the life of the MAS, its CMRL element will remain until termination. If the counter wraps while the MAS stays connected to the CMAS, it is possible that a subsequent request sent to the MAS will have a PSID with the same four byte numeric value as the PSID of the hearbeat task. When this occurs, CTES will fail while adding a duplicate key to the CMRL, resulting in the errors documented above.
Problem conclusion
CTES has been updated to turn on the high order bit in the numeric portion of the PSID before adding the CMRL element for the heartbeat task. Since the hearbeat task is only sent to a MAS once during its run, and since no other CMRL entries last over the entire run of a MAS, this will ensure that CTES does not encounter a duplicate key while adding CMRL elements.
Temporary fix
FIX AVAILABLE BY PTF ONLY
Comments
APAR Information
APAR number
PK99102
Reported component name
CICS TS Z/OS V4
Reported component ID
5655S9700
Reported release
60M
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-10-20
Closed date
2009-10-22
Last modified date
2009-11-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK51222
Modules/Macros
EYU0CTES
Fix information
Fixed component name
CICS TS Z/OS V4
Fixed component ID
5655S9700
Applicable component levels
R60M PSY UK51222
UP09/10/24 P F910
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:
04 November 2009