Re: Activation groups for beginners

[Scott Klement <klemscot@xxxxxxxxxxxx>]

Here's an example of a collision.

    a) I write an accounts payable application for our company.  I call
         the activation group "ACCT".

    b) Someone else goes out and buys an accounts receivable application,
         and the vendor who wrote it, coincidentally, also named the
         activation group "ACCT".

    c) A supervisor who supervises both accounts payable and accounts
         receivable logs on, and accesses both applications (without
         signing off in between)

    d) When she accesses the vendor's receivables app, some overrides
         to (say) QSYSPRT are still in effect, causing a conflict.

Here's another scenario:

    a) Our company supports 5000 programs.

    b) Each time a new program is written, the programmer has to decide
         what resources it uses, and which will be shared with any other
         job, to avoid conflicts.

    c) If two programmers accidentally use the same actgrp, they might
         share resources quite by accident -- but this may not be
         discovered, because the problem only manifests itself when
         certain programs are run in a certain sequence.

With a Named ACTGRP, you're saying "I will group related applications
together, and I will manage them so that they don't conflict".

With *NEW, it's almost a completely different philsophy.  You say "This
program should not share resources with it's caller"  or you say "This
program is intended to share resources with it's caller"   This leads to
something that's somewhat easier to figure out.   Generally, if you don't
know (and therefore don't trust) the application that's going to call a
program, you use *NEW.  If your program is intended to be called from
another program as a utility, or if you know exactly who's allowed to call
it, you use *CALLER.

At least, that's how I look at it, and it seems to work.


On Mon, 11 Mar 2002, Peter Dow wrote:
>
> Here's a point of confusion -- if an AG is a subdivision of a job, then why
> is it necessary to avoid naming conflicts with AG's in other applications
> when using NAG's?
>