Re: Technique critique?

On Wed, 2016-05-18 at 19:33 +0000, Denis Robitaille wrote:

Hello,

We have used this technique a lot over here. One of the problem with it is that if the batch job fails and you forget to reset the data area, your interactive program will never start until the user gets tired and call the help desk and that the help desk figure out that the data area is not up to date.

I would proposed the following instead:

Have the batch job put an exclusive lock on the data area at it's beginning and release it at the end.

Then the interactive jo tries to put a share lock on the data area (ALCOBJ). You can put a wait delay on the ALCCMD of several hours if you which. The interactive job will then wait until the lock is release before continuing.

Here are a few benefits of this approach:
- if the batch job end abnormally, the lock is release. You don't have to edit the data area
- if the interactive program is already running when the batch program start, the batch program will wait until it can get a lock or times out (you can specify how long to wait before timing out)
- no more goto
- if the wait is too long, you can program an appropriate action (like sending a message)

While I have used that approach in the past for specific things I guess
its usefulness would depend on the requirements of the OP's system. If
it needs to prevent jobs starting "until the job completes
_successfully_" then locking an object would fail as a cancelled or
aborted batch job would unlock the object and allow new interactive work
to start.

All that said... I personally would not put an interactive job into some
kind of wait loop, or even in a single long wait, and would instead
chuck a user readable message up the message queue ("batch job still
running, try again later...") or at the very least limit the loop to X
tries with a status message counting down.

Hope this help


Denis Robitaille
Chef de service TI - Solution Entreprise
Infrastructure et Opérations
Cascades Centre des technologies,
412 Marie Victorin
Kingsey falls(Québec) Canada J0A 1B0
T : 819 363 6130



-----Message d'origine-----
De : RPG400-L [mailto:rpg400-l-bounces@xxxxxxxxxxxx] De la part de Bob Cagle
Envoyé : 18 mai 2016 14:46
À : RPG400-L@xxxxxxxxxxxx
Objet : Technique critique?

This is more of a CL programming question:

Background: I have an interactive program that I need to have NOT run while a specific batch job is running. Currently the batch job updates a data area with a flag at the start of the job and then clears it at the end. Interactive jobs can then check for this flag before running.

I have this code in my CL:

CHECK:
/* Check data area to see if job is running */ Rtvdtaara DataArea rtnvar(&Check) If (&Check = '1') then( DO )

/* wait 30 seconds and then try again */ Dlyjob dly(30)
Goto CHECK
ENDDO


The GOTO is bothering me, so the question is - would you code this different? This seems simple and straight-forward, but in your opinion is there a better way?

Thanks

Bob Cagle
IT Manager
Lynk

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