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The Question is:
I have a system that uses global commons to hold current value tables, updated
at least once a second. I would like to have that table automatically
refreshed on a separate CPU (connected via network) so that I can write
programs to extract data for anal
ysis and distribution without adding loading to the primary processor. Can I
do that?
The Answer is :
An update frequency of once a second is profoundly slow on any recent
OpenVMS system -- accordingly, the OpenVMS Wizard will assume this
is an older and slower or a heavily-loaded OpenVMS VAX system, and
you will want to address the system loading and available performance
head-room more directly.
Global sections and commons are entirely node-local constructs, you
would have to use your own synchronization and communications
mechanisms for off-node access, or (if within a cluster) you could
use -- as the OpenVMS Wizard often prefers to -- RMS files with
global buffers enabled. (By the time you get done coding the shared
memory synchronization and the cluster communications, you will have
(re)implemented what RMS with global buffers already provides.)
As for targeting programs to a particular processor within an SMP
system, there are OpenVMS system services for this purpose.
For other folks that are reading this reply, example programs showing
global sections and commons are available in the Ask The Wizard area.
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