Re: Excessive amount of database backups triggered
1999-03-23 08:33:57
Subject: |
Re: Excessive amount of database backups triggered |
From: |
Nathan King <nathan.king AT USAA DOT COM> |
Date: |
Tue, 23 Mar 1999 07:33:57 -0600 |
Bruce,
This is the problem we experienced. In each case a hung client session was
the culprit that was locking the recovery log.
We applied the appropriate fixtest for hung sessions and have never had the
problem reoccur.
Nathan
-----Original Message-----
From: Bruce Elrick [SMTP:belrick AT HOME DOT COM]
Sent: Monday, March 22, 1999 7:13 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Excessive amount of database backups triggered
There are cases where log pages get locked by a transaction that is
not
completing and the log tail (the log is a circular buffer) cannot be
advanced
past that page. When the database backup is finished, it tries to
advance the
log tail to the point in the log where the database ended, but if
there's a
locked page it can't; the % util of the log remains above the
dbbackuptrigger
and immediately another DB backup starts.
Recycling the ADSM server at that point rolls back the transaction
and unlocks
the page; the log tail jumps forward to its proper position.
Cheers...
Bruce
Richard Sims wrote:
> >Time after time, a database backup was triggered almost
immediately after
> >the last one completed. This happened 12 times before the system
(probably)
> >ran out of scratch tapes:
> >Why does this happen?
>
> The Recovery Log having reached the DBBackuptrigger value,
especially
> repeatedly, is obviously a symptom of a LOT of activity. What
sessions
> were active? What was going on? Look at your Activity Log and
> accounting records for client activity.
> Richard Sims, BU
--
Bruce Elrick, Ph.D.
mailto:belrick AT home DOT com
http://members.home.net/belrick/
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