Re: Interval for launching the table sync worker

At Thu, 06 Apr 2017 17:02:14 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> wrote in <20170406(dot)170214(dot)263553093(dot)horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>
> At Thu, 6 Apr 2017 16:15:33 +0900, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote in <CAD21AoCrcwi3SwKKOW_efwW0finxyycLgsbw09n5uy2sxneO_A(at)mail(dot)gmail(dot)com>
> > On Thu, Apr 6, 2017 at 3:45 PM, Kyotaro HORIGUCHI
> > <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> wrote:
> > > I was thinking the same.
> > >
> > > At Thu, 6 Apr 2017 11:33:22 +0900, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote in <CAD21AoDCnyRJDUY=ESVVe68AukvOP2dFomTeBFpAd1TiFbjsGg(at)mail(dot)gmail(dot)com>
> > >> Hi all,
> > >>
> > >> While testing table sync worker for logical replication I noticed that
> > >> if the table sync worker of logical replication failed to insert the
> > >> data for whatever reason, the table sync worker process exits with
> > >> error. And then the main apply worker launches the table sync worker
> > >> again soon without interval. This routine is executed at very high
> > >> frequency without interval.
> > >>
> > >> Should we do put a interval (wal_retrieve_interval or make a new GUC
> > >> parameter?) for launching the table sync worker?

Hmm. I was playing with something wrong. Now I see the invervals
5 seconds. No problem.

> > > After introducing encoding conversion, untranslatable characters
> > > in a published table causes this situation.
> >
> > I think it's better to make a new GUC parameter for the table sync
> > worker. Having multiple behaviors in wal_retrieve_retry_interval is
> > not good idea. Thought?

So, this is working, sorry.

> I prefer subscription option than GUC. Something like following.
>
> CREATE SUBSCRIPTION s1 CONNECTION 'blah'
> PUBLICATION p1 WITH (noreconnect = true);
>
> Stored in pg_subscription?
>
> > > Interval can reduce
> > > the frequence of reconnecting, but I think that walreciever
> > > should refrain from reconnecting on unrecoverable(or repeating)
> > > error in walsender.
> > >
> >
> > Yeah, that's also considerable issue.
>
> But not to do now.

--
Kyotaro Horiguchi
NTT Open Source Software Center