pg.ddx.io  pgsql-admin@postgresql.org mailing list archive  
help / color / mirror / Atom feed
From: Kevin Grittner <kgrittn@ymail.com>
To: Prashanth Ranjalkar <prashant.ranjalkar@gmail.com>
To: Viktor <viktor@okservers.eu>
Cc: gilberto.castillo@etecsa.cu <gilberto.castillo@etecsa.cu>
Cc: pgsql-admin@postgresql.org <pgsql-admin@postgresql.org>
Subject: Re: Pg 9.1 master-slave replication
Date: Thu, 21 Feb 2013 10:23:25 -0800 (PST)
Message-ID: <1361471005.93321.YahooMailNeo@web162901.mail.bf1.yahoo.com> (raw)
In-Reply-To: <CAMBytETTcUR-+GyZVGJQ2X1tjVTzvHhahnh1+0qfK+vJX=gE3A@mail.gmail.com>
References: <B75CD08C73BD3543B97E4EF3964B7D701F15AD68@CITESMBX1.ad.uillinois.edu>
	<kfjgap$ouk$1@ger.gmane.org>
	<5124F06B.1020508@okservers.eu>
	<36037.192.168.207.54.1361375813.squirrel@webmail.etecsa.cu>
	<5124F40F.5090805@okservers.eu>
	<CAMBytETTcUR-+GyZVGJQ2X1tjVTzvHhahnh1+0qfK+vJX=gE3A@mail.gmail.com>
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-admin>

Prashanth Ranjalkar <prashant.ranjalkar@gmail.com> wrote:

>> Hello, Could explain somebody what will happen, if the slave

> It depends on the type of replication is used.
>
> If it's a slony replication then master continues to work and
> will catch up when slave is available.
>
> However if the Streaming replication is used, [...] once it fills
> all the space, master may go down.

That strikes me a false distinction -- Slony also stores data to be
replicated until the slave becomes available.  Either way you can
control where that is stored, and you need to watch out for space
problems on an extended outage of a replica.

An issue I don't think I've seen mentioned is that if you use
synchronous replication you are telling PostgreSQL not to return an
indication of success for a data-modifying transaction until the
work of that transaction has been persisted on at least one
replica.  To avoid stalls on the master, you may want to define
multiple synchronous replicas, so that when one goes down you keep
running without DBA intervention.

-- 
Kevin Grittner
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


-- 
Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-admin



view thread (5+ messages)

Message-ID: <1361471005.93321.YahooMailNeo@web162901.mail.bf1.yahoo.com>
Permalink:  ../1361471005.93321.YahooMailNeo@web162901.mail.bf1.yahoo.com/
Also on:    postgresql.org/message-id/1361471005.93321.YahooMailNeo@web162901.mail.bf1.yahoo.com

 · 

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-admin@postgresql.org
  Cc: kgrittn@ymail.com, prashant.ranjalkar@gmail.com, viktor@okservers.eu, gilberto.castillo@etecsa.cu
  Subject: Re: Pg 9.1 master-slave replication
  In-Reply-To: <1361471005.93321.YahooMailNeo@web162901.mail.bf1.yahoo.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox