From: Jan Wieck <JanWieck@Yahoo.com>
To: Joshua D. Drake <jd@commandprompt.com>
Cc: schen@graciousstyle.com
Cc: pgsql-general@postgresql.org
Subject: Re: replication
Date: Mon, 09 Aug 2004 09:31:42 -0400
Message-ID: <41177CBE.7070803@Yahoo.com> (raw)
In-Reply-To: <4113C627.9030205@commandprompt.com>
References: <4113BB1C.9020106@graciousstyle.com>
<4113C627.9030205@commandprompt.com>
On 8/6/2004 1:55 PM, Joshua D. Drake wrote:
> Hello,
>
> The two main replication products available are:
>
> Slony-I and Mammoth Replicator.
>
> Slony-I: Open Source, trigger based, batch replication.
>
> Mammoth Replicator: Closed Source (source license available), integrated
> (no triggers), live and batch replication.
Out of curiosity, what is the difference between live and batch
replication?
Slony-I has shown recently that it can achieve replication lags down to
a second average, with sporadic spikes up to several seconds on packet
loss in a WAN setup. That was replicating to a virtual machine running
on a notebook and the DB connections ssh-tunneled over two wireless
links and the internet ... not exactly what one would call a production
grade network connection. The server was running a TPC-W ordering mix at
that time, processing about 60,000 transactions per hour resulting in
15,000 row updates per hour (the PHP session data was DB-based and
replicated too). A 10 hour fallback of the replica (the slave system was
moved from Philadelphia to Toronto and back a weekend later :-) ) was
cought up in 3 hours against the continuously running main server over
the WAN, and in about 1.5 hours back in the WLan.
>
> They are both good solutions (I work for the creators of Mammoth
> Replicator) that serve different purposes.
Right (and I am the initial creator of Slony-I). Slony-I as a pure
trigger based approach for example does not aim at fully automatic DDL
replication.
Jan
--
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To: pgsql-general@postgresql.org
Cc: JanWieck@Yahoo.com, jd@commandprompt.com, schen@graciousstyle.com
Subject: Re: replication
In-Reply-To: <41177CBE.7070803@Yahoo.com>
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