Re: BUG #4744: Windows 2008: FATAL: could not reattach to shared memory: 487 - Mailing list pgsql-bugs

From Alvaro Herrera
Subject Re: BUG #4744: Windows 2008: FATAL: could not reattach to shared memory: 487
Date
Msg-id 20090401120444.GB7629@alvh.no-ip.org
Whole thread Raw
In response to BUG #4744: Windows 2008: FATAL: could not reattach to shared memory: 487  ("grouvi" <ghr@sylob.com>)
Responses Re: BUG #4744: Windows 2008: FATAL: could not reattach to shared memory: 487  ("Ghislain ROUVIGNAC" <ghr@sylob.com>)
List pgsql-bugs
grouvi wrote:

> I have the following messages in logs.
>
> 2009-04-01 07:01:05 CEST Tx[0] cmd[] PID[2224] DB[] WARNING:  worker took
> too long to start; cancelled
> FATAL:  could not reattach to shared memory (key=288, addr=01FF0000): 487

"worker took too long" is an autovacuum launcher message.  It's saying
that it tried to start a worker, but it never did.  If the FATAL message
is occuring earlier than the other one, it's possible that it's the
worker failing to start.  (Note that if there's a lot of work for
autovac to do, it will try to start a new worker as soon as it detects
that the old one has failed to start.  So it's quite likely that you'd
see the WARNING first immediately followed by the FATAL message.  In
fact I'd expect exactly this behavior -- this pair of messages showing
up fairly regularly, perhaps almost exactly every autovacuum_naptime
seconds.)

As for the actual problem, "could not reattach to shared memory", that's
a Windows problem that has been reported before, and there has been some
investigation about it and how to fix it, but nothing conclusive has
been found as far as I know.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

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