Re: Deadlock situation? - Mailing list pgsql-general

From Dan Armbrust
Subject Re: Deadlock situation?
Date
Msg-id 82f04dc40804300917o4882e0cbh358a197d57523f4e@mail.gmail.com
Whole thread Raw
In response to Re: Deadlock situation?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
>  I wonder whether you saw some variant of the deadlock reported in bug
>  #3883 --- see discussion here:
>  http://archives.postgresql.org/pgsql-hackers/2008-01/msg00873.php
>  The only known way of getting into that problem is fixed in 8.3,
>  but a potential for silent deadlock is definitely still there.
>  I don't however have any idea how such a deadlock could occur without
>  at least some processes showing as 'waiting' in pg_stat_activity.
>
>  Do you have any idea what the transactions that were blocked at
>  COMMIT had been doing?

Should have just been selects and updates, and perhaps some inserts
and deletes - nothing to out of the ordinary or complex.

If I can get this to happen consistently, I'll set up a logger to
capture all of the SQL statements leading up to the freeze.

>
>  Are there any foreign key constraints leading *to* this table?

Nope.

Unfortunately, I had been running for a couple of weeks steady before
I got the error - so reproducing it may not be quick.  But I'm going
to set up a couple of parallel tests on more systems, and see if I can
happen into it again sooner.

Oh, and I don't think though should have anything to do with it, but I
did discover that fsync was turned off on this postgres instance.
Someone else didn't clean up after a different test, and I forgot to
change it back.

Thanks,

Dan

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