topic Re: cron facility for openvms in Operating System - OpenVMS

cron facility for openvms

himabindu s — Thu, 17 Dec 2009 04:54:08 GMT

Hi,

Is there any cron facility available for OpenVMS similar to Unix?
I have a command procedure and that should be executed every 2 days, so if we have a cron facility, how can we add that command procedure to the cron job?

Thanks,
Hima Bindu S

Re: cron facility for openvms

Steven Schweda — Thu, 17 Dec 2009 05:04:08 GMT

A Forum search for keywords like, say,
batch resubmit
should find examples showing how to do things
like this without a "cron".

A Forum search for "cron" should find some
things, too.

It's pretty common to have a job which runs
every day, and decides whether it's the right
day to do some particular task (particular
day of the week or month, date, day after a
day when the task wasn't done, ...).

Re: cron facility for openvms

Karl Rohwedder — Thu, 17 Dec 2009 05:48:36 GMT

If you want to do it the unix way, here is a cron facility e.g.:

http://www.the-rohwedders.de/downloads/index.html

The crontab entry would be something like:

# min hour day month weekday job
00 09 * * 1,3,5 MYJOB/QUEUE=MYQUEUE/LOG=MYLOG

starts the MYJOB.COM at 09:00 on monday, wednesday and friday.

regards Kalle

Re: cron facility for openvms

Steven Schweda — Thu, 17 Dec 2009 05:58:21 GMT

> [...] every 2 days [...]

> [...] on monday, wednesday and friday.

Not really the same thing, is it?

Re: cron facility for openvms

himabindu s — Thu, 17 Dec 2009 08:17:05 GMT

Thanks for ur replies...
My question is do we have any cron tab facility by default in OpenVMS similar to that we have in Unix?

Re: cron facility for openvms

Volker Halle — Thu, 17 Dec 2009 08:37:28 GMT

Hima,

the answer is no. There is no cron utility in OpenVMS. There is a queue manager subsystem, which provides some of the functionalities of cron, but not all of them.

Volker.

Re: cron facility for openvms

John Gillings — Thu, 17 Dec 2009 20:31:37 GMT

Hima,

> do we have any cron tab facility by
> default in OpenVMS

OpenVMS is not Unix. Unix is not OpenVMS. Things are done differently in different operating environments.

On OpenVMS the queue manager is used to control periodic execution of jobs. This is a different mechanism from cron. It has different strengths and weaknesses. The model is very different.

I'd suggest you try to approach OpenVMS without expecting it to work like Unix. It doesn't. You will be frustrated and disappointed if you expect it to.

Instead of asking "where is cron" you should be asking "how do I execute a job periodically". Think in terms of the problem, not your expected solution.

The same is true going the other way OpenVMS people need to rid themselves of OpenVMS biases when working with Unix.

Even when there is (apparently) a port of cron to OpenVMS, chances are it won't be a 100% match. You're better off finding out about the new environment and working WITH it, rather than trying to force fit it into the model of another environment.

Re: cron facility for openvms

Peter Zeiszler — Fri, 18 Dec 2009 15:37:28 GMT

http://forums13.itrc.hp.com/service/forums/questionanswer.do?admit=109447627+1261150461694+28353475&threadId=1035856

You might be able to use some of the knowledge from this older post.

No Cron in VMS.
Help Queue or help submit. Go from there on managing jobs to run specific days.

Re: cron facility for openvms

Hoff — Fri, 18 Dec 2009 16:04:54 GMT

Process control and process management on OpenVMS is a very weak area of OpenVMS; cron is a comparatively primitive solution even on Unix and Linux, and many of the Unix platforms have better solutions (eg: launchd, HighTORC C3, puppet, ganglia, any of the various grid services), and accordingly cron itself is being replaced by various alternatives on these platforms.

Unfortunately and somewhat inexplicably, there's nothing as fancy as even cron on OpenVMS as yet, barring the cron ports that are around.

Which means you are left to use a port of cron, to acquire another open-source or commercial job scheduling package for OpenVMS, or to learn how to hack this on OpenVMS using batch.

Re: cron facility for openvms

Rob Young_4 — Sun, 20 Dec 2009 02:38:04 GMT

Hima,

Yes.. there is a cron.

See code here:

http://groups.google.com/group/comp.os.vms/msg/dd91f0c133daaeba?dmode=source

And related support .com post here:

http://groups.google.com/group/comp.os.vms/msg/e69f0e54fe65b6db?dmode=source

Note that link above has a "watcher" program. It was such an important part of what I was doing, I could not have cron running (i.e. important production .com jobs were ran out of cron).

The original author is Jim Gessling. You can google groups.google.com and get some of the back story.

Rob

Re: cron facility for openvms

Rob Young_4 — Sun, 20 Dec 2009 02:53:24 GMT

Hima,

One other point. That was written back in the day. Prior to Itanium.

This will still work:

$ is_alpha == 'f$getsyi("hw_model")' .gt. 1024

But should probably be changed to is_fast
where it says is_alpha

I warn to test this in non-production prior to implementing and make no claims as to how well it will work for you.

Rob

Re: cron facility for openvms

himabindu s — Sun, 20 Dec 2009 11:02:22 GMT

Thank You for ur answers...

I will work with job queue manager..

Thanks,
S.Hima Bindu