Fujii Masao wrote:
Intuitively by looking at the enumeration of replication_mode I'd think that
the sync standbys are all standby's that operate in a not async mode. That
would be clearer with a boolean sync (or not) and for sync standbys the
replication_mode specified.
You mean that something like synchronous_replication as the recovery.conf
parameter should be added in addition to replication_mode? Since increasing
the number of similar parameters would confuse users, I don't like do that.
I think what would be confusing if there is a mismatch between
implemented concepts and parameters.
1 does the master wait for standby servers on commit?
2 how many acknowledgements must the master receive before it can continue?
3 is a standby server a synchronous one, i.e. does it acknowledge a commit?
4 when do standby servers acknowledge a commit?
5 does it only wait when the standby's are connected, or also when they
are not connected?
6..?
When trying to match parameter names for the concepts above:
1 - does not exist, but can be answered with quorum_standbys = 0
2 - quorum_standbys
3 - yes, if replication_mode != async (here is were I thought I had to
think to much)
4 - replication modes recv, fsync and replay bot not async
5 - Zoltan's strict_sync_replication parameter
Just an idea, what about
for 4: acknowledge_commit = {no|recv|fsync|replay}
then 3 = yes, if acknowledge_commit != no
regards,
Yeb Havinga
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