On Fri, Sep 17, 2010 at 7:41 PM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
>> The question is do we want standby registration on master and if so,
>> why?
>
> Well, aside from how to configure synchronous replication, standby
> registration would help with retaining the right amount of WAL in the
> master. wal_keep_segments doesn't guarantee that enough is retained, and
> OTOH when all standbys are connected you retain much more than might be
> required.
Yep.
And standby registration is required when we support "wait forever when
synchronous standby isn't connected at the moment" option that Heikki
explained upthread. Though I don't think that standby registration is
required in the first phase since "wait forever" option is not used in
basic use case. Synchronous replication is basically used to reduce the
downtime, and "wait forever" option opposes that.
Regards,
--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center