This section describes how to record, playback, and print WATCH data files. In addition to watching the system in interactive mode, WATCH allows you to record the information in a file and play it back at a later time. Using record it's possible to collect WATCH information with a batch job without tieing up a terminal, then review it at a later date.
RECORD
To record information, use the /RECORD=file_name qualifier. As the information is collected, it will be written to the file. If you don't specify any directory information, the data file is created in the account from which WATCH was run. Use /START_TIME and /END_TIME to control when recorded starts and stops. The /NODISPLAY qualifier can be added to the WATCH command to prevent WATCH data from being displayed; using this qualifier it is possible to set up DCL command procedures and batch jobs to collect and analyze system data.
PLAYBACK
To view data from a previously recorded file, use the /PLAYBACK=file_name qualifier. In this case, the /INTERVAL=time indicates the viewing interval rather than the collection interval. You can record data with an interval of 60 seconds then play it back with an interval of 5 seconds. This shortens the viewing time dramatically.
Use the new /CONDENSE=nnn qualifier to display only every nnnth screen. This significantly speeds up playback without affecting the displayed values since all recorded screens are included in the calculations for accuracy.
You can use the /START_TIME qualifier to specify a starting time for viewing the record file. This allows you to skip around in the file and view different time intervals easily. The time specified is an absolute time, in OpenVMS standard time format. If the start time is not specified, it defaults to the start of the record file.
You cannot change the /TOP qualifier when you view a recorded file and you cannot issue the USERS command.
You also use the /PLAYBACK qualifier when generating a /REPORT=SUMMARY to indicate which previously recorded data file is to be used for input.
NOTE: When doing a playback, the time field shows the time at the moment of data collection, not the current time.
PRINT
To print data from a previously recorded file, use the /PRINT qualifier. It requires two parameters _ the record filename and the output or destination filename. The report consists of two WATCH screens per page of output. You can print part of the data using the /START_TIME and /END_TIME qualifiers. The /COMPARISON qualifier can also be used to specify the format of the comparison numbers. See the section on Watch external commands for the proper syntax.
The new /CONDENSE=nnn qualifier works with print to include only every nnnth screen in the print file. This significantly reduces the number of screens in the print file without affecting the printed values since all recorded screens are included in the calculations for accuracy.
SUMMARY
Version 5 of WATCH includes a new two-page summary report. To summarize data from a previously recorded file use the new /REPORT=SUMMARY qualifier-keyword combination. The summary will be generated to the screen or can be directed to a file with the new /OUTPUT qualifier. An example of this new report is in Appendix B. You can use /START_TIME and /END_TIME to summarize only a portion of the data file.
A sample WATCH batch procedure is included in WATCH_COM called WATCH_MONITOR.COM. This procedure can be easily modified to suit your site’s requirements. It resubmits for 24 hours later, records data for a 24 hour period and then generates three summary reports; peak-usage time, prime time and non-prime time. These reports are mailed to the system manager.