Your description of the solution sounds very much like rserv, except
that rsev keeps the changes in a table in the database ... are you
concerned about the data being inside PG for replication?
We are looking for an HA solution that can handle synchronization of the
failover and have been looking at rserv and its commercial cousin
erserver. I am also looking for feedback from users on either approach.
Let me know if you hear anything :-)
Charlie
Anand Buddhdev wrote:
>I want to be able to keep 3 geographically separate PGSQL databases
>synchronised. I looked at rserv, which is distributed with the later
>versions, and it seems to work well. However, unless I read the
>documentation wrong, it will only work with one master and one slave.
>
>I am also not sure how resilient rserv is to network outages in the middle
>of a synchronisation process. I attempted to interrupt one rserv sync
>process, and noticed that the remote slave database was not modified,
>and later, when the network was available again, it synced correctly. But
>one such test is no guarantee about its resilience. Could anyone shed
>more light on rserv's reliability?
>
>Is anyone doing database replication using other means? How do they
>achieve it?
>
>I was thinking of alternative ideas, and I came up with a simple solution
>myself, but I don't know if it's the right way to go about it. My
>solution involves generating insert/delete/update queries and writing
>them out to files each time the master server is changed. And then have
>a queue runner process collect these queries, and execute them remotely
>on each slave database using the psql tool. Thus the slaves would be
>updated asynchronously, and that's not a problem, as long as they do
>get updated within a few minutes of the master. In case the network
>was not available when the queue runner was processing the requests,
>then it can just try later.
>
>I would appreciate ideas and suggestions.
>
>Thanks,
>
>
>
--
Charles H. Woloszynski
ClearMetrix, Inc.
115 Research Drive
Bethlehem, PA 18015
tel: 610-419-2210 x400
fax: 240-371-3256
web: www.clearmetrix.com
