Skip site navigation (1) Skip section navigation (2)

Re: testing hot standby

From: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
To: Jaime Casanova <jcasanov(at)systemguards(dot)com(dot)ec>
Cc: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: testing hot standby
Date: 2010-04-12 10:49:34
Message-ID: 4BC2FABE.2010300@enterprisedb.com (view raw or flat)
Thread:
Lists: pgsql-hackers
Jaime Casanova wrote:
> On Fri, Apr 9, 2010 at 3:39 PM, Jaime Casanova
> <jcasanov(at)systemguards(dot)com(dot)ec> wrote:
>> but, my main concern is why it was asking for
>> "000000010000000000000006"? is this normal? is this standby's way of
>> saying i'm working but i have nothing to do?

Yes.

>> when that happens after a standby restart, is normal that i have to
>> wait until the file is created before it can accept connections?
> 
> ok, i see this again in a new env. seems like this happen when i
> shutdown standby and primary (in that order) after making some
> WAL-logged action on the primary an then start again primary and
> standby (in that order)... it doesn't occur always but it does occur
> too often, still i'm not sure what is the key factor that triggers
> this

Perhaps you're being bitten by the "can't start hot standby from a
shutdown checkpoint" issue I've complained for a long time. There's a
pending patch for that, see
http://archives.postgresql.org/pgsql-hackers/2010-04/msg00222.php.

If that's what's hitting you, the way to reproduce is:

1. shut down primary
2. shut down standby
3. start standby
4. start primary.

The standby will get hung until it receives an online checkpoint record
from the primary. Connecting to the primary and issuing a manual
CHECKPOINT helps.

That's not the order of shutdowns you described, though...

-- 
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com

In response to

pgsql-hackers by date

Next:From: Robert HaasDate: 2010-04-12 10:52:05
Subject: Re: GSoC - proposal - Materialized Views in PostgreSQL
Previous:From: Heikki LinnakangasDate: 2010-04-12 10:41:58
Subject: Re: Streaming replication and a disk full in primary

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group