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