Re: Issues with Quorum Commit

On Thu, Oct 7, 2010 at 3:01 AM, Markus Wanner <markus@bluegap.ch> wrote:
> Of course, it doesn't make sense to wait-forever on *every* standby that
> ever gets added. Quorum commit is required, yes (and that's what this
> thread is about, IIRC). But with quorum commit, adding a standby only
> improves availability, but certainly doesn't block the master in any
> way.

But, even with quorum commit, if you choose wait-forever option,
failover would decrease availability. Right after the failover,
no standby has connected to new master, so if quorum >= 1, all
the transactions must wait for a while.

Basically we need to take a base backup from new master to start
the standbys and make them connect to new master. This might take
a long time. Since transaction commits cannot advance for that time,
availability would goes down.

Or you think that wait-forever option is applied only when the
standby goes down?

Regards,

-- 
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center