[Pgpool-general] PgPool with Slony?

[Thomas Hallgren]

Hi,
I posted the questions below regarding Slony-I on their mailing list and 
got the suggestion to look at pgpool-II + slony + heartbeat. I see that 
a Pgpool-HA also exists that includes heartbeat. Given the requirements 
that I have, would Pgpool-HA + Slony-I be a good solution for me? Can I 
find some whitepapers or similar somewhere that outlines a solution like 
that?

Regards,
Thomas Hallgren


Hi,
I'm trying to wrap my head around Slony-I and how to use it from an 
application server like JBoss with Hibernate. I'm not clear on the 
relationship between actual connections established by a client and 
nodes in the cluster.

Is it true that any connection that is established is either connected 
to a slave or to the master (origin) for a specific replication set? 
I.e. there's no node in between that will redirect updates to the master 
for the replication set in question?

I'm trying to figure out how to do a controlled switchover and the 
implications of doing that. My appservers can work with two different 
connections if needed but it will be somewhat cumbersome if they need to 
change their settings when I do a switchover. Is there a way to do 
switchover and maintain the connection settings (i.e. host, database, 
credentials)? Ideally, the connections should survive the switch.

I'm also looking into automatic switchover in case the master fails for 
some reason. The Heartbeat product seems to be useful for this. Are you 
aware of any examples on how to do this? Any pointer or hint would be 
useful.