Message-ID: <4671CDB1.3090708@commandprompt.com>
Date: Thu, 14 Jun 2007 16:22:25 -0700
From: "Joshua D. Drake" <jd@commandprompt.com>
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To: Craig James <craig_james@emolecules.com>
CC: pgsql-performance@postgresql.org
Subject: Re: Replication
References: <4671CBBA.6010104@emolecules.com>
In-Reply-To: <4671CBBA.6010104@emolecules.com>
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Craig James wrote:
> Looking for replication solutions, I find:
> 
> Slony-I
> Seems good, single master only, master is a single point of failure,
> no good failover system for electing a new master or having a failed
> master rejoin the cluster.  Slave databases are mostly for safety or
> for parallelizing queries for performance.  Suffers from O(N^2) 
> communications (N = cluster size).

Yep

> 
> Slony-II
> Seems brilliant, a solid theoretical foundation, at the forefront of
> computer science.  But can't find project status -- when will it be
> available?  Is it a pipe dream, or a nearly-ready reality?
> 

Dead


> PGReplication
> Appears to be a page that someone forgot to erase from the old GBorg site.
> 

Dead


> PGCluster
> Seems pretty good, but web site is not current, there are releases in use
> that are not on the web site, and also seems to always be a couple steps
> behind the current release of Postgres.  Two single-points failure spots,
> load balancer and the data replicator.
> 

Slow as all get out for writes but cool idea

> Is this a good summary of the status of replication?  Have I missed any 
> important solutions or mischaracterized anything?
> 

log shipping, closed source solutions


> Thanks!
> Craig
> 
> 
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