On Sun, Aug 11, 2013 at 5:51 AM, ascot.moss@xxxxxxxxx <ascot.moss@xxxxxxxxx> wrote: > Hi, > > I have a pair of PG servers, a master and a replica, all read-write queries are handled by the master, read-only ones are by the replica. > > From time to time the replica itself is too busy, all read-only queries will get inconsistent results because of replication lag, sometimes it can be longer than 6 minutes. I am thinking to add multiple replicas to off-load read-only queries, can you please suggest a way to monitor and failover the read-only query when the replication lag in a replica is more than 5 minutes? I assume that you could use pgpool for that. It has some monitoring features for replication delay and it can do read-only load balancing among several servers. You also shouldn't need to change your application. Have a look at its documentation to make an opinion: http://pgpool.projects.pgfoundry.org/pgpool-II/doc/pgpool-en.html Regards, -- Michael -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
