The active log preformat utility (CSQJUFMT)

You can use the CSQJUFMT utility to format active log data sets before they are used by a queue manager.

If the active log data sets are preformatted by the utility, log write performance is improved on the queue manager's first pass through the active logs. If the utility is not used, the queue manager must format each log control interval at log write time before it is used. On the second and subsequent passes through the active log data sets, the log control intervals already contain data, so need no further formatting, and no performance benefit accrues.

Invoking the CSQJUFMT utility

You can only run the CSQJUFMT program before starting the queue manager that use the logs.

Note: Do not use this utility to format a log data set after the queue manager has started, or data will be lost.


EXEC PGM=CSQJUFMT

Each step running the CQJUFMT utility formats a single active log dataset. Add additional CSQJUFMT steps for each active log being created.

Attention: JCL limits the number of steps in a single job to 255. If you are formatting more than 255 active log datasets, you will need to run multiple jobs.

These DD statements should be provided:

SYSPRINT: This statement is required to specify a data set or print spool class for print output.
SYSUT1: This statement identifies the log data set to be preformatted.

Figure 1. Example of the JCL used to invoke the CSQJUFMT utility


  //JOBLIB    DD   DISP=SHR,DSN=thlqual.SCSQANLE
  //          DD   DISP=SHR,DSN=thlqual.SCSQAUTH
  //*
  //JUFMT11   EXEC PGM=CSQJUFMT
  //SYSPRINT  DD   SYSOUT=*
  //SYSUT1    DD   DISP=OLD,DSN=hlq.LOGCOPY1.DS01
  //*
  //JUFMT21   EXEC PGM=CSQJUFMT
  //SYSPRINT  DD   SYSOUT=*
  //SYSUT1    DD   DISP=OLD,DSN=hlq.LOGCOPY2.DS01

Sample JCL is supplied in thlqual.SCSQPROC (CSQ4LFMT) for preformatting a newly defined dual log data set. It contains two steps, one step to format each of the copies of the log data set.