troubleshooting Change Notification Registrations?

From: Mark Harrison <>
Date: Wed, 28 Oct 2009 14:17:21 -0700
Message-ID: <6y2Gm.4430$>

I've got a program that uses OCI Change Notification callbacks.

On my test system, everything works perfectly... I get a callback every time I modify my table.

On my production system, I never get a callback.

An odd thing I've noticed: when running

     SELECT CALLBACK FROM USER_CHANGE_NOTIFICATION_REGS on my working test system, the callback HOST= points to my client computer. This makes intuitive sense, since it's a registration for a callback.

(46, 4, 'net8://(ADDRESS=(PROTOCOL=tcp)(HOST=',
    0, 0, 1800, 'MH.CBDEMO')
   # = client box

On my busted production system, the callback HOST= string points to the database server.

(271, 4, 'net8://(ADDRESS=(PROTOCOL=tcp)(HOST=',
    0, 0, 1800, 'MH.CBDEMO')
   # = database node

So, two questions:

  1. Is it the case that HOST= should always point to the client machine?
  2. What's the best way to troubleshoot a problem with change notifications like this?

Many TIA!

Mark Harrison
Pixar Animation Studios
Received on Wed Oct 28 2009 - 16:17:21 CDT

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