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Re: Postgres 7.4.6 hang in async_notify

From: Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl>
To: pgsql-bugs(at)counterstorm(dot)com
Cc: pgsql-bugs(at)postgresql(dot)org
Subject: Re: Postgres 7.4.6 hang in async_notify
Date: 2005-04-25 20:55:41
Message-ID: 20050425205541.GC29834@dcc.uchile.cl (view raw or flat)
Thread:
Lists: pgsql-bugs
On Mon, Apr 25, 2005 at 03:42:35PM -0400, pgsql-bugs(at)counterstorm(dot)com wrote:

> The way the notify gets called is a bit convoluted.  Our C program
> performs an insert in table T.  Some triggers run doing all sorts of
> stuff in the background involving changes to other tables.  Under some
> circumstances, a row is inserted by the trigger into table W (a
> trigger off of that is executed) and the parent trigger performs a
> notify.  This, while expensive, normally all works.  However, at a
> customer site we saw the postgres process hang out in async_notify and
> refuse to allow more inserts.

What do you mean by "in the background"?  Do you fork() the backend
process?

IIRC there have been bugs in listen/notify by which a backend could hang
forever.  Some were fixed, but others main remain.  Can you post more
details of the involved functions and triggers?

-- 
Alvaro Herrera (<alvherre[(at)]dcc(dot)uchile(dot)cl>)
One man's impedance mismatch is another man's layer of abstraction.
(Lincoln Yeoh)

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Next:From: pgsql-bugsDate: 2005-04-25 21:43:31
Subject: Re: Postgres 7.4.6 hang in async_notify
Previous:From: Juan VillaDate: 2005-04-25 20:08:16
Subject: BUG #1625: INTALL PROBLEM

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