A fix is available
APAR status
Closed as program error.
Error description
This is the enabling APAR for a portion of APAR PM69760. ... For the timing window when the SCA REBUILD tries to obtain the DBET hash lock while a mainline DBET updater is in the notify exit path, the SCA REBUILD timeout will not be resolved until this enabling APAR, which should be applied only after APAR PM69760 has been applied on all data sharing members. ... The preconditioning APAR PM69760 still fixes major scenarios of the SCA REBUILD timeout so it still has significant value even before the enabling APAR is applied. ... The following sample illustrates the SCA REBUILD timeout: --------------------------------------------------------- DSNT376I - PLAN=BCT WITH 398 CORRELATION-ID=014.RBDBET01 CONNECTION-ID=V91A LUW-ID=DSNCAT.SYEC1DB2.CA3071BF1397 THREAD-INFO=SYSOPR:*:*:* IS TIMED OUT. ONE HOLDER OF THE RESOURCE IS PLAN= WITH CORRELATION-ID=020.JOBSTO07 CONNECTION-ID=V91A LUW-ID=DSNCAT.SYEC1DB2.CA3071B10954=7 THREAD-INFO=SYSOPR:*:*:* ON MEMBER V91A DSNT501I - DSNILMCL RESOURCE UNAVAILABLE 399 CORRELATION-ID=014.RBDBET01 CONNECTION-ID=V91A LUW-ID=DSNCAT.SYEC1DB2.CA3071BF1397=0 REASON 00C900C0 TYPE 00002105 NAME INTERNAL LOCK 05 DSN7504I - DSN7LST2 400 SCA STRUCTURE DSNCAT_SCA REBUILD UNSUCCESSFUL. REASON CODE = 8. IXC522I REBUILD FOR STRUCTURE 401 DSNCAT_SCA IS BEING STOPPED TO FALL BACK TO THE OLD STRUCTURE DUE TO CONNECTOR SPECIFIC REASON USER CODE: 00000008 IXC521I REBUILD FOR STRUCTURE DSNCAT_SCA 405 HAS BEEN STOPPED ---------------------------------------------------------------- . Exposure if the enabling APAR PM74803 were to be applied on any member before applying the preconditioning APAR PM69760: The exposure is that if SCA REBUILD is running and there is a concurrent DBET activity (e.g. a utility running on a member without the enabling APAR PM74803 and turning on UTRW), members that have the enabling APAR on might ignore the notify to turn on an exception state for an object. So members in the group could get out of synch between each other with regard to a DBET state - some will have it turned on, some won't, which could lead to allowing access to the object when it should be protected by DBET state. However, this chance for inconsistency is only if there is SCA REBUILD running and only if the member that has the enabling APAR on isn't the one driving the DBET activity (and therefore originating DBET notifies).
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All DB2 10, DB2 9 and DB2 V8 for z/OS data * * sharing users of the z/OS SETXCF REBUILD * * command when issued against SCA * **************************************************************** * PROBLEM DESCRIPTION: Timeout MSGDSNT376I MSGDSNT501I with * * RC00C900C0 TYPE00002105 may occur in * * data sharing when a REBUILD of the SCA * * structure is issued (e.g. * * SETXCF START,REBUILD,STRNM=DSNCAT_SCA), * * resulting in stoppage of the rebuild, * * with messages MSGDSN7504I, MSGIXC522I * * and MSGIXC521I, caused by concurrent * * mainline DBET updater that happens to * * be in the notify exit path * * * * (PM74803 is the enabling APAR for a * * portion of APAR PM69760's code.) * **************************************************************** * RECOMMENDATION: * **************************************************************** REBUILD of the SCA structure may experience a timeout on resource type 00002105 when running concurrently with database exception table (DBET)-heavy activity such as during utility workloads that turn on/off various DBET states like UTRW, RBDP etc. The following sample illustrates the issue: ---------------------------------------------------------------- DSNT376I - PLAN=BCT WITH 398 CORRELATION-ID=014.RBDBET01 CONNECTION-ID=V91A LUW-ID=DSNCAT.SYEC1DB2.CA3071BF1397 THREAD-INFO=SYSOPR:*:*:* IS TIMED OUT. ONE HOLDER OF THE RESOURCE IS PLAN= WITH CORRELATION-ID=020.JOBSTO07 CONNECTION-ID=V91A LUW-ID=DSNCAT.SYEC1DB2.CA3071B10954=7 THREAD-INFO=SYSOPR:*:*:* ON MEMBER V91A DSNT501I - DSNILMCL RESOURCE UNAVAILABLE 399 CORRELATION-ID=014.RBDBET01 CONNECTION-ID=V91A LUW-ID=DSNCAT.SYEC1DB2.CA3071BF1397=0 REASON 00C900C0 TYPE 00002105 NAME INTERNAL LOCK 05 DSN7504I - DSN7LST2 400 SCA STRUCTURE DSNCAT_SCA REBUILD UNSUCCESSFUL. REASON CODE = 8. IXC522I REBUILD FOR STRUCTURE 401 DSNCAT_SCA IS BEING STOPPED TO FALL BACK TO THE OLD STRUCTURE DUE TO CONNECTOR SPECIFIC REASON USER CODE: 00000008 IXC521I REBUILD FOR STRUCTURE DSNCAT_SCA 405 HAS BEEN STOPPED ---------------------------------------------------------------- The reason for the timeout of the SCA REBUILD is that a mainline DBET updater (e.g. a utility) is suspended (while holding the DBET hash lock) by the SCA REBUILD process. When the SCA REBUILD tries to obtain the same lock, it cannot do so because the holder is suspended and therefore the SCA REBUILD times out. APAR PM74803 is particularly for the timing window when the SCA REBUILD tries to obtain the DBET hash lock while a mainline DBET updater is in the notify exit path.
Problem conclusion
Code has been changed to adjust the serialization scheme between mainline DBET updaters and the SCA REBUILD process. APAR PM74803 is the enabling APAR for a portion of APAR PM69760. APAR PM74803 should be applied only after APAR PM69760 has been applied on all data sharing members. Additional keywords: DB2DSHR SYSPLEXDS
Temporary fix
********* * HIPER * *********
Comments
ž**** PE13/06/20 PTF IN ERROR. SEE APAR PM91546 FOR DESCRIPTION
APAR Information
APAR number
PM74803
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
910
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt
Submitted date
2012-10-11
Closed date
2013-01-09
Last modified date
2013-08-10
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK90830 UK90831 UK90832
Modules/Macros
DSNIDBEL DSNIDBGN DSNIDBGR DSNIDBNG
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
RA10 PSY UK90830
UP13/01/24 P F301
R810 PSY UK90831
UP13/01/24 P F301
R910 PSY UK90832
UP13/01/24 P F301
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:
10 August 2013