II10072: GTF LOST RECORDS START PROCEDURE, MISSING

APAR status

• Closed as canceled.

Error description

• Keywords:  vtaminfo tpinfo
  The VTAM use of GTF to record VTAM Internal Trace, VIT, can
  produce large amounts of data that will cause GTF to ' miss '
  recording data in the GTF trace data set.  This INFO APAR
  provides a summary of GTF items and where to find more
  information on setting up the GTF cataloged procedure to
  prevent LOST EVENTS.
    For more information on the GTF cataloged procedure, see the
    MVS Tools and Service Aids manual under table of contents
    "The Generalized Trace Facility", Setting up a cataloged
    procedure.
  
  The term * NCP * in this item is referring to the Number of
  Channel Programs for GTF - not the Network Control Program
  familiar to VTAM users.
  
  When tracing an active system, GTF may not be able to keep up
  with the number of events that are being traced.
  A method of using " multiple " GTF output data sets to record
  the GTF trace data is found in "MVS DIAGNOSIS: Tools and
  Services Aids" and other related manuals.
  
  You can use COPYTRC (see MVS IPCS commands) to:
  *  Combine trace data sets, or trace entries or records in dump
     data sets, or both, into a single data Set.
  
  A short GTF summary has been copied to this APAR.
  
   Setting Up a Cataloged Procedure
  
      Set up your own GTF cataloged procedure when you want to
      control details of GTF operation such as:
  
     *   Amount of storage needed for tracing
  
     *   Recovery for GTF
  
     *   Number and type of trace output data sets.
  
  
      If you choose to supply your own cataloged procedure,
      include the following statements:
  
     PROC
         Defines your cataloged procedure.
  
     EXEC
  
         PGM=AHLGTF
             Calls for the system to run program AHLGTF.
  
         PARM='parm, parm...'
            Options specified on the PARM parameter specify where
            GTF writes trace data and the amount of storage needed
            for GTF to collect and save trace data in various dump
            types.  parm can be any of the following:
  
                  MODE={INT|EXT|DEFER}
                  SADMP={nnnnnnK|nnnnnnM|40K}
                  SDUMP={nnnnnnK|nnnnnnM|40K}
                  NOPROMPT
                  ABDUMP={nnnnnnK|nnnnnnM|0K}
                  BLOK={nnnnn|nnnnnK|nnnnnM|40K}
                  TIME=YES
                  DEBUG={YES|NO}
  
             BLOK={nnnnn|nnnnnK|nnnnnM|40K}
                 Specifies the amount of virtual storage (CSA)
                 that GTF will use to collect trace data.  Specify
                 this storage amount in 4096-byte pages (nnnnn),
                 or in bytes (nnnnnK or nnnnnM).  The maximum
                 amount is 99999; the default is 40K.  If the
                 amount is less than 40K, GTF will use the
                 default.
  
             TIME=YES
                 Specifies that every GTF trace record have a time
                 stamp, as well as the block time stamp associated
                 with every block of data.  The time stamp is the
                 eight-byte time of day (TOD) clock value at the
                 local time in which GTF puts the record into the
                 trace table.  (TOD clock values are described in
                 Principles of Operation.)  GTF does not accept
                 TIME=NO; all output records will have time
                 stamps.
  
                 When you use IPCS to format and print the trace
                 records, a time stamp record follows each trace
                 record.  You can use these time stamp records to
                 calculate the elapsed time between trace entries.
                 The time stamp record is described in the "Time
                 Stamp Records" topic.
  
  
     IEFRDER DD or GTFOUTxx DD
         Defines the trace output data set or data sets.  This
         statement is required only if you do one of the
         following:
  
         *   Specify MODE=EXT or MODE=DEFER
         *   Use the default MODE=EXT
  
         IEFRDER DD can be used, but does not have to be used, for
         one trace output data set.  Additional data sets must be
         defined on GTFOUTxx DD statements, where xx is one or two
         characters that are valid in DDNAMES.  See "Guidelines
         for Defining GTF Trace Output Data Sets in a Cataloged
         Procedure" in the topic for guidance on how to define
         output data sets for GTF.
  
   Guidelines for Defining GTF Trace Output Data Sets in a
   Cataloged Procedure
  
     Use the following guidelines for specifying trace output
     data sets on the IEFRDER DD or GTFOUTxx DD statements:
  
     *   You can define up to 16 output data sets for GTF to use.
         If you define more than 16 data sets, GTF will accept the
         first 16 and ignore the rest.
  
     *   If GTF cannot open all of the data sets, it issues a
         message that identifies those that are unopened, and
         continues processing with those that are open.
  
     *   Do not specify the RLSE option when the SPACE parameter
         is used because the output data sets will be opened and
         closed more than once while GTF runs.
  
     *   Do not specify extents for an output data set.  Extents
         are ignored if specified.
  
     *   All data sets must be in the same device class:  either
         DASD or tape, but not both.  If you mix device classes,
         GTF will ignore the tapes and use only DASD.  However,
         the data sets can have different device types; for
         example, you can mix 3350 and 3380 device types.
  
     *   To ensure the most efficient GTF processing, do not
         specify any particular block size for the output data set
         or data sets in either:
  
         -   The cataloged procedure for GTF
         -   The JCL, TSO/E commands, or interactive system
             productivity facility/program development facility
             (ISPF/PDF) panels that you might use to preallocate
             the data set or data sets
  
         The system computes an optimal block size when it opens
         each data set.  EXCEPTION:  If you want GTF to use an
         unlabeled tape as the output data set, you must specify
         the logical record length and block size when you
         allocate that data set.
  
     *   If you define more than one data set, you should ensure
         that the number of paths to the data sets equals the
         number of data sets.
  
     *   You can specify the number of channel programs for each
         output data set using the NCP parameter on each DD
         statement.  The NCP value determines the rate at which
         GTF transfers data to the output data sets.  For example,
         if you want to transfer data to your data sets at a rate
         of 25 buffers per second and you have 5 data sets, you
         will need to specify an NCP value of 5. GTF then
         transfers data to the 5 data sets at a rate of 5 buffers
         per second per data set for a total rate of 25 buffers
         per second.
  
         The maximum value for NCP is 255.  If you do not specify
         a value for NCP, or if you specify a value less than
         four, GTF will use the following default values:
  
         -   For tape:  four
         -   For DASD:  the number of output blocks per track,
             multiplied by four.
  
     *   If, when you enter the START command, you override any
         of the DD statements for multiple output data sets, you
         must use symbolic parameters in those DD statements.  See
         "Using the START Command to Invoke GTF" in topic 9.7.1
         for more information.
  

Local fix

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Temporary fix

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• Information APAR
  

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