Re: question about HA in PG 9.0

Windows server enterprise has the Microsoft Cluster Services.

This enable fail-over scenario between two computers.

So, when one of them go offline, the other is activated, this involve many
steps, including IP changing, the slave become the master IP address .

But you can choose between has a replication between both postgres or maybe
you can put your postgresql DATA directory to an external storage shared
between those two servers.

If this case, when the second server become available the Cluster service
map map the DATA unit and starts the postgres service.

So, you have everything running and working in aprox. 10 seconds.

De: pgsql-admin-owner(at)postgresql(dot)org
[mailto:pgsql-admin-owner(at)postgresql(dot)org] En nombre de Kasia Tuszynska
Enviado el: viernes, 17 de septiembre de 2010 07:30 p.m.
Para: pgsql-admin(at)postgresql(dot)org
Asunto: [ADMIN] question about HA in PG 9.0

Hi Everybody,

I am doing a bit of research about High Availability solutions offered as
part of core in Postges 9.0, I have couple of questions, sorry if they
expose my novice status where it comes to HA on Postgres:

1. The doc is lovely but all of the examples are for linux, has anyone
tired a Hot Standby streaming scenario on windows? Any issues specific to
windows? I know that linux and windows environments "should" behave the
same but actually running in both of those environments exposes many
differences.

2. I am reading the Beta4 doc where under section 25.3 Failover it
says:

"PostgreSQL does not provide the system software required to identify a
failure on the primary and notify the standby database server. Many such
tools exist and are well integrated with the operating system facilities
required for successful failover, such as IP address migration."

I have been reading up on this issue most notably on
http://wiki.postgresql.org/wiki/Shared_Storage, where the suggestions have
been gravitating to solutions on the physical level.

Are there any software level solutions? ( I have a feeling that this may be
a stupid question, but I want to implement this in the cloud, and not
potentially kill an ami instance)

I found a presentation by Heikki Linnakangas where he mentions: Heartbeat
and Shoot the other Node in the head as types of 3rd party high availability
tools, does anyone have any recommendations of specific software packages?

Thank you,

Sincerely,

Kasia