[Pgpool-hackers] proposal for new feature

[mitani]

Hi all,

I'm a developer of the PGCluster which is a multi-master synchronous replication tool for PogstreSQL.
I have used pgpool as a loadbalancer of PGCluster for a long time (about eight years).

I would like to propose new features for pgpool-II to bolster an availability.

In order to prevent single point of failure, two or more pgpool sets should be put in a system. In this case, there are two type of composition. 
(1) Single master and multi slave composition
If the master pgpool failed, the slave pgpool might take over it.
I know there are some tools which is designed to build redundant system like a Heartbeat, DRBD and Lifekeeper etc. However, these tools are not so easy to build up. And these are not enouth for database redundancy I think.
If pgpool-II has this function in it self, user might be pleased to use it.
(2) Multi master composition 
I know that pgpool-II can be used like a multi master composition.
However, if one pgpool execute online backup, other pgpools are not block  sessions.
I think that it needs a cooperate action for online backup.

I'll create some patches within a few monthes if nobody oppesed it.
I would like to have a comment about it.

Regards,
-- 
at.mitani