Re: Multiple databases

Hi there,

We have just implemented a similar system on a RedHat AS2.1 cluster, Two
Dell PowerEdge 2650s (1x2.8GHz Xeon, 2x2Gb RAM) connected to a Dell
PowerVault220S disc array via Perc 3/DC cards. Runs like a dream.

We have two logical hosts, one for the live environment, the other for the
test.

Each is configured to listen on its own port (as per your option 1), and
each has its own set of binaries, libraries etc to allow for testing of
upgrades etc. Each PostgreSQL installation is also owned by a different UNIX
user as this made things easier for us to manage.

The only fun we have had was to write a wrapper for scripts/cron jobs to
ensure the relevent logical host was present on the physical box, and to
setup the relevant enviroment variables.

To do option 2, wouldn't you have to shutdown the existing postmaster (and
clients) so that it could see the second data area?

Regards

John

--
John Hosen
Senior Web Developer

Tel: 01256 383708
Fax: 01256 383811
Mob: 07801 136525

www.capitaras.co.uk

> -----Original Message-----
> From: Greg Spiegelberg [mailto:gspiegelberg(at)cranel(dot)com]
> Sent: 14 October 2003 15:02
> To: Postgres Admin List
> Subject: [ADMIN] Multiple databases
>
>
> Hiya,
>
> We're looking into ways to cluster our database servers and
> shared storage. Here's the low-down on our servers... all
> run RedHat 7.3 with a few patches and are dual PIII 1.4GHz,
> 2GB, mirrored internal 36, Qlogic 2310 HBA to a LUN on our
> Hitachi. PostgreSQL 7.3.3 is installed from source and the
> one that came with RH has been removed.
>
> There are currently 3 of these servers and each are designed
> to run 1 instance of PostgreSQL with 10-20 databases of
> varying size from 5 to 20GB. I have PostgreSQL pretty well
> tweaked to maximize memory so I'm hesitant to have a 2nd
> instance running on the server in the case of a failover.
>
> This is what I'm curious about.
>
> Server A has it's databases under /pg/dataA and Server B has
> it's databases under /pg/dataB both are different LUN's on
> our SAN. Should Server A choke, Server B should fsck
> /pg/dataA and mount it locally. At this point it needs to either
>
> (1) start a new instance of PostgreSQL listening on 5432/tcp
> but bound to a different IP
> or
> (2) the current PostgreSQL "imports" the databases under
> /pg/dataA
>
> Each have their good points and problematic issues.
>
> Thoughts?
>
> Greg
>
> --
> Greg Spiegelberg
> Sr. Product Development Engineer
> Cranel, Incorporated.
> Phone: 614.318.4314
> Fax: 614.431.8388
> Email: gspiegelberg(at)Cranel(dot)com
> Cranel. Technology. Integrity. Focus.
>
>
>
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