Understanding Checkpoint reports
The checkpoint reports provide statistics that you can use to analyze the application program checkpoints and other call activity that occurred during application program execution. AR/CTL inserts a report heading like the one in the following figure at the beginning of each report. The heading identifies the current date and time, the title of the report, and the page number within the sequence of the set of reports.
Report heading
TIME: 09:37:11.55 A P P L I C A T I O N R E S T A R T C O N T R O L
CHECKPOINT STATISTICS REPORT
ENVIRONMENT DESCRIPTION
Most fields on the checkpoint reports are self-explanatory, with the following exceptions:
- Date fields are reported as Julian dates in yyyyddd format, where yyyy is the year and ddd is the day of the year (1 to 366).
- Time fields are reported in hh:mm:ss.th format, where hh is the hour (00 to 23), mm is the minute (00 to 59), ss is the second (00 to 59), t is the tenth of a second, and h is the hundredth of a second.
- Fields that report an elapsed time are calculated by subtracting the start time of the action from the end time of the action. This time can include system, subsystem, and other delays that may not be related directly to the action being processed.
Fields that report the number of checkpoints issued and the number of checkpoints completed refer to the application program checkpoint calls. If the application program issues DB2 commit calls that AR/CTL is translating to checkpoint calls, the number of checkpoint calls includes the count of translated DB2 commit calls.
It is valid to have a higher number of issued checkpoint calls than the number of completed checkpoint calls; a checkpoint call can be bypassed with checkpoint pacing or a user exit routine.
AR/CTL provides the following checkpoint reports: