Automatically switching operation logs

When the File Access Log file or the Command Execution Log file reaches a certain size, HULFT automatically creates a backup file of log records that have already been output. This function allows you to limit the disk space used by the operation logs to a certain value and to regularly collect and save operation logs to a log server.

HULFT alternates two VSAM files for each of the two log files (the File Access Log file and the Command Execution Log file) to which HULFT writes logs. If the operation log output cannot be written to a file because the file is full, HULFT switches the output destination to the other VSAM file. The original file is initialized after its content is copied to the Sequential Organization generation file.

For details on generation files, refer to the manual for the operating system.

To enable automatic switching of the operation logs, specify the following parameters in the System Environment Settings file (HULFT.PARMLIB(HULPRM)):

<Fields Always Required>

  • Command Execution Log Backup Output Volume Name

  • File Access Log Backup Output Volume Name

  • UNIT Name of Operation Log Output Data Set

  • Command Execution Log Backup Output Data Set Name

  • File Access Log Backup Output Data Set Name

  • Operation Log Auto Switch Job Name

  • Subsequent Job Addition Step STEPLIB Settings 1

<Required Fields Depending on Environment in Use>

  • Class

  • Message Class

  • Job Operand 1

  • Job Operand 2

 

For details about the System Environment Settings file (HULFT.PARMLIB(HULPRM)), refer to System Environment Settings.

Figure 2.40 Automatically switching operation logs

1) Size check

When Operation Log file 1 has sufficient space for outputting the operation log records, HULFT does not switch the Operation Log files.

2) Switching

When Operation Log file 1 does not have sufficient space for output data, HULFT switches the output destination to Operation Log file 2.

HULFT then backs up the content of Operation Log file 1.

3) Operation Log output

HULFT outputs the operation log records to Operation Log file 2.

HULFT initializes the log file control record of Operation Log file 1.