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

Re: Question about multiple slaves and Master loss.

From: Evan Rempel <erempel(at)uvic(dot)ca>
To: "Nicholson, Brad (Toronto, ON, CA)" <bnicholson(at)hp(dot)com>
Cc: Chris Hoover <revoohc(at)gmail(dot)com>, "pgsql-admin(at)postgresql(dot)org Admin" <pgsql-admin(at)postgresql(dot)org>
Subject: Re: Question about multiple slaves and Master loss.
Date: 2011-12-07 18:11:51
Message-ID: 4EDFAC67.9040809@uvic.ca (view raw or flat)
Thread:
Lists: pgsql-admin
Can you have a slave of a slave?

Basically set up

A --> B --> C
also
A --> D --> E

if A goes down, promote B which is protected by C
If B goes down, D is your protection for A
If C goes down, who cares.

It takes 5 machines, but would give great protection.

Evan.


Nicholson, Brad (Toronto, ON, CA) wrote:
> *From:* pgsql-admin-owner(at)postgresql(dot)org 
> [mailto:pgsql-admin-owner(at)postgresql(dot)org] *On Behalf Of *Chris Hoover
> *Sent:* Wednesday, December 07, 2011 12:05 PM
> *To:* pgsql-admin(at)postgresql(dot)org Admin
> *Subject:* [ADMIN] Question about multiple slaves and Master loss.
> 
>  
> 
> I'm pretty sure that the answer to this question is no, but I wanted to 
> verify.
> 
>  
> 
> Given the following scenario (pg 9.0):
> 
>  
> 
> Server A (Master), Server B (A's streaming replication Slave), Server C 
> (A's streaming replication Slave)
> 
>  
> 
> If you lose Server A, is there anyway to promote Server B to master and 
> keep Server C as B's slave without having to rebuild C from a backup of B? 
> 
>  
> 
> Basically, I'd like to be able to have 2 slaves running so that when the 
> master goes down, we can bring one slave online, and still have the 
> ability to very quickly recover if the new master where to fail before 
> server A could be recovered.
> 
>  
> 
> Thanks,
> 
>  
> 
> Chris
> 
>  
> 
> Not that I am aware of.  In practice though, C and B should me more or 
> less equivalent so as long as you are using a differential copy like 
> rsync you should be able to bring C up as a replica of B very quickly.  
> There is of course a small window though where you are not protected.
> 
>  
> 
> Brad.
> 


-- 
Evan Rempel                               erempel(at)uvic(dot)ca
Senior Systems Administrator                 250.721.7691
Unix Services, University Systems, University of Victoria

In response to

Responses

pgsql-admin by date

Next:From: Nicholson, Brad (Toronto, ON, CA)Date: 2011-12-07 18:15:17
Subject: Re: Question about multiple slaves and Master loss.
Previous:From: Nicholson, Brad (Toronto, ON, CA)Date: 2011-12-07 17:58:44
Subject: Re: Question about multiple slaves and Master loss.

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