Runaway Oracle user processes.

From: <pihlab_at_cbr.hhcs.gov.au>
Date: 23 Feb 94 16:03:17 +1100
Message-ID: <1994Feb23.160317.1_at_cbr.hhcs.gov.au>


We were suffering from runaway Oracle user processes and I thought the net might want to know what caused it and our workaround, so ...

We are running VAX/VMS 5.5-2 and Oracle 7.0.13.

If a user gets into an Oracle product (SQL*Plus, SQL*Forms, etc) and then does a BREAK & DISCONNECT (ie exits the session without going through the normal logoff procedure) their VMS session goes into an infinite CPU loop and uses up all available CPU time.

I reported this to the Oracle HOTLINE here in OZ and they said they had never had this problem reported before.

After a lot of testing and having a nice friendly Systems Engineer from Digital's HOTLINE login and monitor the processes way down inside the O/S we discovered that it is a bug in the Oracle7 EXIT handler. The Digital engineer was trying to resolve the same problem on an ALPHA box in New Zealand so he was determined to trace this bugger down.

Many many many thanks to the good work and assistance from Digital in tracking down an Oracle bug. No thanks at all to the Oracle HOTLINE who haven't even bothered to return my call of last week.

The code was looping in a user mode exit handler (possibly reinitialising itself each time round) and was looking for or a DCL AST CONTROL_Y handler that wasn't there.

Anyway, further testing showed that if you have the CONTROL_Y key DISabled then you get this problem but if it is ENABLED then the problem went away. Also, the New Zealand user was asked to test this and found that it was true on his ALPHA/VMS box running 7.0.13 but his other VAX/VMS box running 7.0.15 didn't have the problem. I guess this means that Oracle fixed a problem that had never been reported to them 8^}.

Because we don't want users to normally have CONTROL_Y access we have had to make modifications to our Oracle security to enable and then trap CONTROL_Y.

Hope that helps someone else out there.

Good luck.

-- 
Bruce...        pihlab_at_cbr.hhcs.gov.au

"If you swallow a live frog first thing in the morning ...
 Nothing worse will happen to either of you for the rest of the day."

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* Bruce Pihlamae -- Database Administration *
* Commonwealth Department of Human Services and Health *
* Canberra, Australia (W) 06-289-7056 *
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* These are my own thoughts and opinions, few that I have. *
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Received on Wed Feb 23 1994 - 06:03:17 CET

Original text of this message