HP OpenVMS Systems

Process Deletion and Locking?

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The Question is:

 
One of our clients have a process running on our Alpha machine, they want to
 terminate idle processes after a certain amount of time.
I believe they're using a hardware solution to accomplish that at the moment.
 The problem is that when the idle processes are killed, it sometimes leaves
 their current records locked.  We would want to write a program or command
 procedure so that it clea
rs any record/file locks after killing the process.  Is it possible to do that,
 given the process's username?  Or, alternatively, is there some sort of
 "cleanup" program available in that clears "orphan" locked records?
 

The Answer is :

 
 
  If using the OpenVMS distributed lock manager, OpenVMS cleans up
  the locks of deleted processes; the current RMS records and files
  are automatically unlocked, and any other uses of the distributed
  lock manager are also resolved -- the lock manager provides rather
  more than file and record locks, and is often used for tasks such
  as intracluster interprocess communications and intracluster
  process management.
 
  It is obviously possible for an application to use other
  application-specific locking techniques, and any such clean-up
  involved is accordingly and entirely application-specific.
 
  With a software-based process deletion, initial use of $forcex is
  generally recommended over $delprc -- $delprc may eventually be
  needed, but it is generally not the best initial choice.  (Various
  idle-process deletion tools are discussed in the OpenVMS FAQ.)
  $forcex causes the process exit handlers to be invoked, while
  $delprc does not; $delprc is a process hard-kill operation.
 
  As is common practice, process deletions and power failures
  can have similarities and can potentially leave applications
  and application data in inconsistent states -- transaction
  and database systems are common solutions when there are
  multi-part update operations and/or the necessity of an
  ability to back-out transactions, and database packages and
  RMS journaling are options.
 
  For general programming discussions, please see topic (1661)
  and topics referenced there.
 
  DECamds and Availability Manager can be used to view OpenVMS
  locks, but, again, the OpenVMS Wizard would not assume these
  are in use here as locks owned by processes are released when
  the processes are deleted and when a cluster member node
  exists the cluster.
 
  Do ensure you have the current ECOs for OpenVMS, of course.
 
 

  

     

     
answer written or last revised on ( 10-SEP-2004 )
     
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