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Examples: Making SYNCVAL work for you IBM Health Checker for z/OS User's Guide SC23-6843-02 |
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SYNCVAL={hh:mm|*:mm) sounds more complex than it is. This section will go into a bunch of detail about how it works, but don't let all this verbiage scare you - in the end, SYNCVAL just lets you establish a synchronization point so that you can predict and control when a check is scheduled to run. Note that in the examples below, we talk about coordinating with INTERVAL. But all this information also applies to EXCEPTINTERVAL. Example 1 - I want exact run times for my check: Lets
say we've got a check, CHECKA. Because we like to do things the best
and most efficient way, we set up a nice policy statement for CHECKA
for our HZSPRMxx parmlib member so that the way we want the check
to run is preserved in perpetuity. We need this check to run at synchronized
predictable intervals, so we have the following list of assumptions
for our CHECKA:
Once this policy takes effect, the system schedules the check to run at 12:00 and every 30 minutes thereafter, at exactly 12:30, 1:00, 1:30 and so on. If you already have CHECKA defined and running on the system when you set up a policy statement with SYNCVAL for it, you have to refresh your check in order for the initial SYNCVAL start time take effect. However, note that if you add CHECKA in the future, it is synchronized to 15,30,45, and 0 minutes after the hour, even without a REFRESH. Now, just for fun, we'll add EXCEPTINTERVAL(HALF) to
the ADDREPLACE policy:
Once this policy takes effect, if the check finds an exception the interval time is halved, so that the system schedules the check to run at 12:00 and every 15 minutes thereafter, at exactly 12:15, 12:30, 12:45 and so on. Example 2 - I want my check to run at a specific time every
day: I want to run CHECKB once a day at midnight (00:00) so
it's not interfering with any other applications (not that a check
typically makes much performance impact). Here's a policy statement
that will make that happen:
Now, when the policy takes effect,
the check is scheduled to run once a day exactly at midnight. Example 3 - I want my check to run at the same minute of the
hour, every time it does run: I just want to be able to predict
that CHECKC will only run at 15 minutes past the hour when it runs
(for example, because my system has other work scheduled every hour)
at the top of the hour. I want CHECKB to run every 6 hours, but at
15 minutes past the hour. Here's my statement:
That works. But look out for
the gotchas; SYNCVAL and INTERVAL have to synch up, if you will. For
example, SYNCVAL(*:15) INTERVAL(06:00) will work.
But SYNCVAL(*:15) INTERVAL(00:18) will not work -
you're asking the system to run CHECKC every 18 minutes at 15 minutes
after the hour. SeeSYNCVAL restrictions |
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