From: Chris Browne <cbbrowne@acm.org>
Subject: Re: replica of database
Date: Thu, 11 Sep 2008 18:18:32 -0400
Organization: cbbrowne Computing Inc
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To: pgsql-admin@postgresql.org

bnichols@ca.afilias.info (Brad Nicholson) writes:
> On Thu, 2008-09-11 at 12:19 -0600, Scott Marlowe wrote:
>> On Thu, Sep 11, 2008 at 8:30 AM, Chris Browne <cbbrowne@acm.org> wrote:
>> > jd@commandprompt.com ("Joshua D. Drake") writes:
>> >> Aftab Alam wrote:
>> >>> Yes ,I want a replica of my db so that I can use it as failover
>> >>>
>> >>>
>> >>>
>> >>> Version 7.3 linux AS release 4 update 6
>> >>
>> >> Version 7.3 is end of life and I don't know of *any* of the
>> >> replication technologies that will work with it.
>> >
>> > Slony-I version 1.1 can still work with 7.3.  We ceased support of 7.3
>> > when we released v1.2, but recommended, at the time, using 1.1 for
>> > 7.3-compatibility.
>> 
>> And as  buggy as slony 1.0 might have been, I ran it for about 2 years
>> in production replicating a HUGE amount of data daily with zero
>> failures. Of course, the servers were fast and reliable, so that might
>> have helped cover a lot of issues other people had for us.
>
> And when we ran it we had replica's getting corrupted due to bugs almost
> weekly (based on a particular pattern of activity).  The edges are
> there.  It did never lose data on us.

Mind you, that was on 7.4, not 7.3.

It's possible that:
 a) 7.4 did new stuff, so that those index corruptions would not have been
    present in 7.3, but also that
 b) 7.3 might have "data-eating problems not present in 7.4."

I *would* suggest using 1.1.[latest], of Slony-I, as that should have
the fewest issues, on the Slony-I side, of any version available to
run against PG 7.3, and should work the most cleanly.

But on the other hand, I'd *also* strongly urge using this to get off
of v7.3 and onto something a LOT newer, ASAP.  I think you can get to
PostgreSQL 8.1 using the 1.1 branch, which is usefully newer :-).
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