HP OpenVMS Systems

Off-node (Cluster) Shared Memory Access?

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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.
 
 

  

     

     
answer written or last revised on ( 22-JUN-2001 )
     
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