HP OpenVMS Systems

File Access (or Creation) Notifications?

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The Question is:

 
We have a shared directory where a few hundred people have access.  The files
 are owned by a RUN account so that the one account can control the files and
 is responsible for the cleanup.
 
We have someone creating a new version of file every ten minutes and it is not
 open for long.  I know that opcom can be setup on a file but I cant find the
 instructions to make a file send an alert when it is accessed.
 
How do I add the specific file or modify the file so that it sends an alert
 when a new version is created?

The Answer is :

 
  If there is an existing and lower version of the file, add an
  audit or alarm ACE to the existing file:
 
    $ SET SECURITY/ACL=(ALARM=SECURITY,ACCESS=WRITE+DELETE+SUCCESS) -
        filename
 
  Alarms target the operator consoles enabled for SECURITY (see the
  command REPLY/ENABLE=SECURITY) while audits target the security
  journal (use ANALYZE/AUDIT) to find them.
 
  If there is not 't an existing file, you can place a similar audit
  or alarm ACE on the directory. This may generate significant traffic,
  but if the interval really is only 10 minutes, that shouldn't be an
  issue.
 
  Experiment with an ALARM ACE to make sure it does what you want.
 
  The interesting part here is that you can create an application that
  receives and can processes these messages directly, using the available
  security listener mechanisms; see the DCL commands SET AUDIT/NOLISTENER
  and SET AUDIT/LISTENER as a start.
 
  Topics such as (4818) and (5819), and possibly (6610), will be of
  some interest here, too, as will a modification of the tool itself;
  changes to the tool to send along the desired and appropriate
  notifications.  Like creation, access can also be audited.
 
  Of course, it is also possible to use a lock within the various
  application images and processes, and to particularly use this
  lock as a doorbell; to trigger a cluster-wide operation that
  either closes and re-opens the file as required, or that controls
  application and process activity when the file contents are
  otherwise updated.
 
  The OpenVMS Wizard would tend to use one of the available access
  coordination (communications) mechanisms within the applications;
  cooperating interprocess communications mechanisms and designs.
 

  

     

     
answer written or last revised on ( 29-NOV-2004 )
     
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