Re: HA solution

On Saturday 15 January 2011 10:07:14 am Jaiswal Dhaval Sudhirkumar wrote:
> Thanks for your support.
>
> We have power full HP servers with lots of CPU cores, I/O bandwidth and
> memory too.
>
> Actually I will give you the environment details, which will help you to
> understand.
>
> It is a huge set-up where we have a DC & DR. There will be lots of daily
> edit and read hits. Also there would be lots of read hits from reporting
> perspective too. Therefore, I thought of to keep one node for edit and
> other one for read (OLTP vs REPORTING) kind of structure for DC & if it
> goes down DR will take care. However in your suggested structure there will
> be only one active node at a time in DC. Even standby database would be in
> recovery mode.
>
> Initially I thought of the set-up slony replication for (OLTP vs REPORTING)
> & pgpool replication for (OLTP vs OLTP) but there will be very huge GIS
> database size & they agreed only on cluster set-up.
>
> I really need thoughts/comments/help from experts.

First a data directory cannot be shared between database clusters. To put it
another away each database cluster you initdb will need to have its own data
directory.

Second with Postgres 9.0+ there is the concept of hot standby whereby the
standby cluster is available for read only operations while it is in recovery
mode. For an idea of what is possible you might to take a look at this blog:

http://blog.2ndquadrant.com/en/2011/01/easier-postgresql-90-clusters.html

Conclusion. Pulling together what has already been posted. If you want to run
two Postgres instances you will need to have two copies of the data. If you
want one copy of the data you will have to work with one instance of Postgres.

>
>
> --
> Thanks & Regards
> Dhaval Jaiswal
>

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com