Michael Paquier wrote: > On Fri, Nov 22, 2013 at 10:03 PM, Kaushal Shriyan <kaushalshriyan@xxxxxxxxx> wrote: >> I am not sure i understand the difference between async and sync replication >> and on what scenarios i should use async or sync replication. Does it mean >> if it is within same DC then sync replication is the best and if it is >> across DC replication async is better than sync. Please help me understand. > In the case of synchronous replication, master node waits for the > confirmation that a given transaction has committed on slave side > before committing itself. This wait period can cause some delay, hence > it is preferable to use sync replication with nodes that far from each > other. I am sure that you wanted to say "with nodes *not* that far from each other". Basically, you have to choose between these options: - Slow down processing, but don't lose a transaction on failover (this would be synchronous, nodes close to each other) - Replicate over longer distances, but possibly lose some transactions on failover (that would be asynchronous). Yours, Laurenz Albe -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
