Thanks so much. On 11 Aug 2013, at 9:50 PM, Michael Paquier wrote: > 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