Обсуждение: must synchronous_standby_names be set?
I'm testing synchronous replication on 9.2devel - both instances are on a single machine. The primary shows synchronous_commit = on and synchronous_standby_names = ''. The standby receives updates fine. Now, does the 'synchronous_commit = on' absolutely mean that the session is sync-replicating? Could it be non-synchronously replicating? If so, this information in the manual seems wrong: " 25.2.6.1. Basic Configuration Once streaming replication has been configured, configuring synchronous replication requires only one additional configuration step: synchronous_standby_names must be set to a non-empty value. " ( the 'must be set' part ) Two questions: 1. How to query a session to make absolutely sure that replication is actually synchronous? 2. Does sync-repl really need synchronous_standby_names to be set? Thank you, Erik Rijkers
On Fri, Jul 1, 2011 at 2:42 PM, Erik Rijkers <er@xs4all.nl> wrote: > Two questions: > > 1. How to query a session to make absolutely sure that replication is actually synchronous? Check synchronous_standby_names and synchronous commit for appropriate values. > 2. Does sync-repl really need synchronous_standby_names to be set? Yes Unset => "synchronise with zero servers" => asynchronous -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
Simon Riggs <simon@2ndQuadrant.com> writes: > On Fri, Jul 1, 2011 at 2:42 PM, Erik Rijkers <er@xs4all.nl> wrote: > >> Two questions: >> >> 1. How to query a session to make absolutely sure that replication is actually synchronous? > > Check synchronous_standby_names and synchronous commit for appropriate values. > also check pg_stat_replication -- Jaime Casanova www.2ndQuadrant.com Professional PostgreSQL Soporte 24x7, desarrollo, capacitación y servicios