Reply-To: <gnanam@zoniac.com>
From: "Gnanakumar" <gnanam@zoniac.com>
To: "'Greg Smith'" <greg@2ndquadrant.com>
Cc: <pgsql-admin@postgresql.org>
References: <001201cb0321$df429d40$9dc7d7c0$@com>
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In-Reply-To: <002701cb74cf$23607f50$6a217df0$@com>
Subject: Re: pg_ctl: server does not shut down
Date: Thu, 28 Oct 2010 13:27:02 +0530
Organization: Zoniac Software Private Limited
Message-ID: <004f01cb7675$b7118120$25348360$@com>
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>> You can check if PITR is disabled by executing:
>> SHOW archive_command;
>> At a psql prompt.  If that's empty, then you turned it off, and it isn't
>> involved in the shutdown issue you have anymore.

> Yes, I could see empty value here.

>> Take a look at what processes are still running against the database and
>> see if there are clients attached after the fast shutdown attempt.  
>> If so, those are your problem, not something to PITR.

> Yes, I can see the following processes still running. I used the command
'ps
> -ef |grep postgres' to list.
> postgres  3376     1  0 07:20 ?        00:00:00
> /mnt/database/pgsql/bin/postgres -D /usr/local/pgsql/data
> postgres  3381  3376  0 07:20 ?        00:00:00 postgres: logger process
> postgres  3383  3376  0 07:20 ?        00:00:00 postgres: writer process

> But why logger and writer process are still running/showing up here for a
> very long time after issuing 'service postgresql stop'.  What could be the
> problem?  Also, am sure here that no other clients (database connections)
> are connected at this time.

I can CONSISTENTLY reproduce this problem (PITR walarchive drive is not
attached/mounted) and I still don't know the reason behind this issue:
1) If I disable PITR and start postgresql service, consistently server does
not shut down on 'service postgresql stop' command.  I have tried and
checked this upto 4 times.
   NOTE: After disabling PITR, on checking "SHOW archive_command" from psql,
it is showing empty value.  But on 'ps -ef |grep postgres', it is always
showing up    
   logger and writer process running.

2) But if I enable back PITR and start postgresql service, consistently
server shuts down properly on 'service postgresql stop' command.  Again I
have tried this cycle also upto 4 times.

When I mean enable/disable PITR, it is about enabling/disabling 2
configuration parameters: "archive_command" and "archive_timeout".

Since this is our Production server, experts assistance to solve this issue
are highly appreciated.