Re: Continuous Archiving for Multiple Warm StandbyServers

On Mon, 2007-05-07 at 15:10 -0500, Thomas F. O'Connell wrote:

> I'm attempting to design a postgres system whereby an authoritative
> primary server simultaneously feeds continuous archives to a number of
> warm standby servers that live both on the local network and on remote
> networks.

> The sticking point in my current thinking about such a system is what
> to do in the event that any of an array of possible nodes becomes
> unreachable. I would expect a custom archive_command to have the
> intelligence about network reachability and to report a nonzero status
> if it was unable to submit an archive to any particular node.

> What is the advised remedy for this scenario in general?

There is no advised remedy. It is designed to allow you to program it
any way you choose.

You can choose to provide maximum availability, by allowing it to work
even when one node is down, or you can choose to provide maximum
protection, by ensuring that it does not work if any node is down. Or
anywhere in between, as requirements dictate.

One of the problems with providing the example as a simple cp command is
that it tends to limit one's thinking about how much flexibility and
control is being offered.

pg_standby is just one of a number of possibilities for integration in
this area. We can easily publish others.

--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com