Re: Divide by zero and monitor group...

[Robert Rogerson <rrogerson@xxxxxxxxxxx>]

Thanks to everyone for your input.  I must admit I learned something new 
about how monitor group behave.  I'll take everyone's advise into 
consideration in the future when coding monitor groups.

Thanks again,

Rob

On 7/1/2015 4:12 PM, Scott Klement wrote:
> Robert,
>
> Monitor groups always log their errors to the job log (no matter what 
> the error happens to be -- this is not unique to divide by zero.)
>
> This can be very handy for troubleshooting problems... and is a 
> feature I really appreciate.
>
> I have a subprocedure in a service program that will remove the error 
> messages from the job log.  So I can have some logic in there that if 
> it's an error I'm expecting, I'll remove the messages (gets rid of 
> useless clutter in the job log) but if it's an unexpected error, I'll 
> leave it in there for diagnostic purposes.  Works very nicely.
>
> You're right that this does have an impact on performance.  You should 
> not use this to catch divide by zero errors if you expect them to 
> happen frequently...   I usually use an 80/20 rule.  If I expect an 
> error to occur less than 20% of the time, it's a candidate for a 
> MONITOR.  If the error will occur more often than that, I write code 
> that anticipates the error and fixes it in advance...
>
> if myfield = 0;
>    result = 0;
> else;
>    result = somefield / myfield;
> endif;
>
> If myField=0 is expected to happen freuently, this will run MUCH MUCH 
> faster than monitoring for the condition...
>
> -SK
>
>
> On 7/1/2015 2:11 PM, Robert Rogerson wrote:
> > Hi all,
> >
> > I was somewhat surprised to find that a divide by zero error inside a
> > monitor group still wrote/added an error/message to the joblog. The
> > message I'm referring to is
> > MCH1211 Escape 40 Message . . . . :   Attempt made to divide by zero for
> > fixed point operation.
> >
> > I was pointed to this error as the reason for the program abending, but
> > when I checked (the specific line specified in the message) in the
> > program it was within a monitor group, so it was already being handled.
> > In the end the issue was elsewhere in the program.
> >
> > With that being said, my question is, doesn't writing to the joblog take
> > up processing time and isn't this message misleading when the program is
> > already handling the error within a monitor group?
> > I know that checking the divisor before doing the divide operation would
> > avoid this issue, but I thought this was one of the purposes of the
> > monitor group.
> >
> > Thanks,
> >
> > Rob