Obtaining a dump of system logger information

Use the following examples to obtain the appropriate diagnostic information for system logger. The amount of information requested in the dumps may be very large. You may need to set your MAXSPACE on the CHNGDUMP setting to 999 mb before obtaining the logger dumps. 
 CD SET,SDUMP,MAXSPACE=999M
For structure dumps, verify that the coupling facility has dump space defined by issuing the following command:
 D CF,CFNAME=xxxx
Note: There are several sample Logger dump parmlib members that can be used as models for automating the procedures listed below. The samples parmlib members are shipped in 'SYS1.SAMPLIB(IEADMCLx)'. Refer to the IEADMCLx members for more information, or see Table 1.
  1. For all types of logstreams, always include the following:
    1. The IXGLOGR (Logger) asid and the data spaces associated with the IXGLOGR asid through the DSPNAME parm. These will be dumped using the JOBNAME= parm.
    2. The trace data space SYSLOGR0, will be included in the dump if DSNAME=('IXGLOGR'.*) is specified in the reply for the dump command.
      Note: If you are running OS/390® Release 2 or lower, Logger will not have a SYSLOGR* data space for tracing, in which case the DSPNAME=('IXGLOGR'.*) option can be omitted.
       DUMP  COMM=(dump system logger with component trace)
 * rr IEE094D SPECIFY OPERAND(S) FOR DUMP COMMAND
 rr,JOBNAME=(IXGLOGR),CONT
 ss,DSPNAME=('IXGLOGR'.SYSLOGR*),CONT
 tt,SDATA=(COUPLE,ALLNUC,LPA,LSQA,PSA,RGN,SQA,SUM,
           TRT,CSA,GRSQ,XESDATA),END
  2. When using CF list structure based log streams, include the following
    1. The XCF asid and trace data spaces. These will be dumped using the JOBNAME= parm and DSPNAME parm.
    2. The XES STRUCTURE data. This is dumped using the STRLIST= parameter and by specifying the structure name. structure_name is the affected STRUCTURE name.
      Note: Be sure to allocate adequate DUMPSPACE() as defined in your CF definition in the CFRM policy. If you do not allocate adequate space, all or part of the STRUCTURE will NOT be dumped.
    3. In the case of “loss of data” or “block not found”, dumping the OFFLOAD data sets using IDCAMS is a good idea.
    DUMP COMM=(dump system logger with xes and structure data)
* rr IEE094D SPECIFY OPERAND(S) FOR DUMP COMMAND
rr,JOBNAME=(IXGLOGR,XCFAS),CONT
ss,DSPNAME=('XCFAS'.*,'IXGLOGR'.SYSLOGR*),CONT
tt,SDATA=(COUPLE,ALLNUC,LPA,LSQA,PSA,RGN,SQA,SUM,
          TRT,CSA,GRSQ,XESDATA),CONT
uu,STRLIST=(STRNAME=structure_name,LOCKENTRIES,ACC=NOLIM,
    (LISTNUM=ALL,ADJUNCT=DIRECTIO,ENTRYDATA=UNSERIALIZE)),END
  3. When system logger dumps are needed on multiple systems in the sysplex, include the REMOTE parameter.
    DUMP COMM=(dumps for system logger around the sysplex)
* rr IEE094D SPECIFY OPERAND(S) FOR DUMP COMMAND
rr,JOBNAME=(IXGLOGR,XCFAS),CONT
ss,DSPNAME=('XCFAS'.*,'IXGLOGR'.SYSLOGR*),CONT
tt,SDATA=(COUPLE,ALLNUC,LPA,LSQA,PSA,RGN,SQA,SUM,
           TRT,CSA,GRSQ,XESDATA),CONT
uu,STRLIST=(STRNAME=structure_name,LOCKENTRIES,ACC=NOLIM,
     (LISTNUM=ALL,ADJUNCT=DIRECTIO,ENTRYDATA=UNSERIALIZE)),CONT
vv,REMOTE=(SYSLIST=*)'XCFAS','IXGLOGR'),DSPNAME,SDATA),END
  4. Other diagnostic considerations

    The CTILOG00 buffer size is 16MB. It is strongly recommended that this value not be lowered. See the CTnLOGxx member, described in Table 1.

    Remember that much of the data that system logger uses is persistent across an IPL. That means that if this data is corrupted and adversely affects system logger, an IPL will not correct the problem. In the case of a persistent system logger failure, you can FORCE the IXGLOGR address space. Prior to doing this you should bring down all of the applications connected. Then issue the FORCE command (FORCE IXGLOGR,ARM) and restart system logger using the supplied procedure in SYS1.PROCLIB (IXGLOGRS). (S IXGLOGRS)

    If FORCE IXGLOGR,ARM does not resolve the situation, an IPL is not likely to either. This is the time to take a dump if one was not already taken by system logger.

    Note:
    1. A CICS® dump will not dump the IXGLOGR address space. Connect to a new (non-corrupted) LOGSTREAM. This will result in a LOSS OF DATA for some applications such as CICS, forcing them to INITIAL START. However, this may be the only way to get the application restarted. Connecting to a new logstream (of a different name) will allow the corrupted data to remain in the structure for diagnostic review later.
    2. In preparation for connecting to this new LOGSTREAM, you may want to define an unused LOGSTREAM to each STRUCTURE during setup.
    If running CICS, always run with the following SLIP: 
    SLIP SET,COMP=1C5,REASON=804,
  STRLIST=(STRNAME=strname1,LOCKE,ACC=NOLIM,
  (LNUM=ALL,EDATA=SER,ADJ=CAP)),
  JL=(XCFAS,IXGLOGR),DN=("XCFAS".*,"IXGLOGR".*),
  SD=(COUPLE,ALLNUC,LPA,LSQA,PSA,RGN,SQA,TRT,CSA,GRSQ,
    XESDATA,SUM),
  SUMLIST=(13R?-7FFF,13R?+7FFF),END
    Note: You might add a JOBNAME=DFH* to limit SLIP to CICS. A RSN804 is a “block not found”, which is always bad for CICS but not necessarily so for other applications. Setting this SLIP will cause system logger to dump on all RSN804s in CICS.
  5. Frequent stumbling blocks
    1. OFFLOAD data sets must be VSAM SHAREOPTIONS(3,3) unless you are in a MONOPLEX.
    2. After OW33261, system logger recommends for performance reasons using 24K CI size for OFFLOAD data sets. Staging data sets must remain at 4K CI size. Code your ACS routines appropriately.
    3. Size of XES structures. “Bigger is not always better.” Follow exploiting application recommendations.
    4. Allow for OFFLOAD directory extents. Reference “Format Utility for Couple Data Sets” in z/OS MVS Setting Up a Sysplex.
    5. System logger uses HSM services to recall (ARCHRCAL) and to delete (ARCHDEL) offload data sets. HSM contention or a wait for a WTOR such as ARC0055A can hang all of the log streams that require the system logger allocation task.
Parent topic: SYSLOGR component trace