Re: pg_basebackup may fail to send feedbacks.

Hello,

At Wed, 4 Feb 2015 19:22:39 +0900, Fujii Masao <masao.fujii@gmail.com> wrote in
<CAHGQGwGudGCMnHZinkd37i+JijDkruEcrea1NCRs1MMtE3rOFQ@mail.gmail.com>
> On Wed, Feb 4, 2015 at 4:58 PM, Kyotaro HORIGUCHI
> <horiguchi.kyotaro@lab.ntt.co.jp> wrote:
> > I'm very sorry for confused report. The problem found in 9.4.0
> > and the diagnosis was mistakenly done on master.
> >
> > 9.4.0 has no problem of feedback delay caused by slow xlog
> > receiving on pg_basebackup mentioned in the previous mail. But
> > the current master still has this problem.
> 
> Seems walreceiver has the same problem. No?

pg_receivexlog.c would have the same problem since it uses the
same function with pg_basebackup.c.

The correspondent of HandleCopyStream in wansender is
WalReceiverMain, and it doesn't seem to have the same kind of
loop shown below. It seems to surely send feedback per one
record.

|   r = stream_reader();
|   while (r > 0)
|   {
|      ... wal record processing stuff without sending feedback..
|      r = stream_reader();
|   }

regards,

-- 
Kyotaro Horiguchi
NTT Open Source Software Center