Date: Fri, 15 Mar 2013 14:55:08 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Rick Otten <rotten@manta.com>
Cc: postgres performance list <pgsql-performance@postgresql.org>
Subject: Re: New server setup
Message-ID: <20130315185508.GA17688@momjian.us>
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On Fri, Mar 15, 2013 at 06:06:02PM +0000, Rick Otten wrote:
> >I don't think any drive that corrupts on power-off is suitable for a
> >database, but for non-db uses, sure, I guess they are OK, though you
> >have to be pretty money->constrainted to like that tradeoff.
>
> Wouldn't mission critical databases normally be configured in a high
> availability cluster - presumably with replicas running on different
> power sources?
>
> If you lose power to a member of the cluster (or even the master), you
> would have new data coming in and stuff to do long before it could
> come back online - corrupted disk or not.
>
> I find it hard to imagine configuring something that is too critical
> to be able to be restored from periodic backup to NOT be in a
> (synchronous) cluster.  I'm not sure all the fuss over whether an SSD
> might come back after a hard server failure is really about.  You
> should architect the solution so you can lose the server and throw
> it away and never bring it back online again.  Native streaming
> replication is fairly straightforward to configure.  Asynchronous
> multimaster (albeit with some synchronization latency) is also fairly
> easy to configure using third party tools such as SymmetricDS.
>
> Agreed that adding a supercap doesn't sound like a hard thing for
> a hardware manufacturer to do, but I don't think it should be a
> necessarily be showstopper for being able to take advantage of some
> awesome I/O performance opportunities.

Do you want to recreate the server if it loses power over an extra $100
per drive?

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +


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