NetNews Usenet Archive 1992 #18/NN_1992_18.iso/spool/comp/os/vms/13834

Internet Message Format | 1992-08-19 | 1.8 KB

Path: sparky!uunet!ukma!darwin.sura.net!zaphod.mps.ohio-state.edu!van-bc!jeslacs!psmode
From: Peter Smode <[e-mail]>
Newsgroups: comp.os.vms
Subject: Re: Clustered Global Section
Message-ID: <[e-mail]>
Date: Wed, 19 Aug 92 09:55:06 PDT
References: <[e-mail]>
Organization: JES Library Automation, Coquitlam BC, CANADA
Lines: 30

[e-mail] (Ian Parker) writes:

>
>
> I'm just about to cluster a couple of VAXs.  On one VAX an application
> uses global sections to communicate between processes.  After clustering
> we want this application to be available across the cluster.
>
> Is there a problem?
>
> Yes, I know that you can't share memory across a cluster, but since
> global sections are mapped to files (but are all sections mapped to
> files?), and assuming that the files are available clusterwide then
> will it work?

As somebody else has already pointed out, this approach is a non-starter.
However, depending upon the type of communication you need, you might be
able to use the VMS lock manager instead. Check out the $ENQ and $ENQW
system services along with $GETLKI. By coming up with a couple of resource
names and access policies, you can do some very slick IPC wether there is
a cluster in place or not.

A really good feature to use is a blocking AST routine to handle process
shutdown with low overhead.

**************************************************************************
*   Peter Smode                 E-mail:    [e-mail]   *
*   JES Library Automation      Voice:     [phone]                 *
*   Coquitlam, BC, CANADA       Fax:       [phone]                 *
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