Re: Sync Rep for 2011CF1

On Wed, Feb 9, 2011 at 5:25 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Tue, Feb 8, 2011 at 2:34 PM, Magnus Hagander <magnus(at)hagander(dot)net> wrote:
>> I also agree with the general idea of trying to break it into smaller
>> parts - even if they only provide small parts each on it's own. That
>> also makes it easier to get an overview of exactly how much is left,
>> to see where to focus.
>
> And on that note, here's the rest of the patch back, rebased over what
> I posted ~90 minutes ago.

Though I haven't read the patch enough yet, I have one review comment.

While walsender uses the non-blocking I/O function (i.e.,
pq_getbyte_if_available)
for the receive, it uses the blocking one (i.e., pq_flush, etc) for the send.
So, sync_rep_timeout_server would not work well when the walsender
gets blocked in sending WAL. This is one the problems which I struggled
with when I created the SyncRep patch before. I think that we need to
introduce the non-blocking send function for the replication timeout.

Regards,

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