HP OpenVMS Systems

Meaning of lock count and locking?

» close window

The Question is:

 
Hi Wizards,
 
I'm trying to describe to a customer what the 'lock count' is on a $show
 cluster and haven't really found any detailed info other than it's a count of
 the ENQ/DEQ activity. What *is* ENQ/DEQ activity?
 
thanks!
 
 

The Answer is :

 
  The OpenVMS Wizard does have some difficulties with guessing what tool
  or command(s) are referenced, and would thus strongly encourage that
  any question provide the specific command(s) used -- please see the
  posting rules for the information that the OpenVMS Wizard requires.
 
  The DCL command SHOW CLUSTER does not display locking statistics.
 
  The MONITOR command does, but it doesn't have a display "lock count".
 
  ANALYZE/SYSTEM (SDA) does display various OpenVMS Galaxy lock counts,
  but these displays do not exist on OpenVMS Alpha V7.1.  SDA also has
  some displays of lock counts in the area of RMS.
 
  To answer your question about ENQ/DEQ activity:  $ENQ is the OpenVMS
  system service that is used to enqueue a lock request.  $DEQ is the
  service that dequeues a lock request.  "Lock count", therefore, is
  presumably the rate at which $ENQ or $DEQ requests are taking place.
 
  Locks are a software construct that are used to provide synchronized
  access to arbitrary objects -- disks, files, records, applications,
  processes, even integers or other 16-byte values -- referenced throughout
  an OpenVMS cluster.  For more information on locks, please start with
  section 2.6 of the OpenVMS Cluster Systems Manual, at:
 
www.openvms.compaq.com:8000/72final/4477/4477pro_003.html#lockman_map
 

  

     

     
answer written or last revised on ( 24-OCT-2000 )
     
» close window