Re: Replication server timeout patch

Fujii Masao wrote:
> On Fri, Mar 11, 2011 at 10:18 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> >> I added this replication timeout patch into next CF.
> >>
> >> I explain why this feature is required for the future review;
> >>
> >> Without this feature, walsender might unexpectedly remain for a while when
> >> the standby crashes or the network outage happens. TCP keepalive can
> >> improve this situation to?a certain extent, but it's not perfect. Remaining
> >> walsender can cause some problems.
> >>
> >> For example, when hot_standby_feedback is enabled, such a remaining
> >> walsender would prevent oldest xmin from advancing and interfere with
> >> vacuuming on the master. For example, when you use synchronous
> >> replication and walsender in SYNC mode gets stuck, any synchronous
> >> standby candidate cannot switch to SYNC mode until that walsender exits,
> >> and all the transactions would pause.
> >>
> >> This feature causes walsender to exit when there is no reply from the
> >> standby before the replication timeout expires. Then we can avoid the
> >> above problems.
> >
> > I think we should consider making this change for 9.1. ?This is a real
> > wart, and it's going to become even more of a problem with sync rep, I
> > think.
>
> Yeah, that's a welcome! Please feel free to review the patch.

It is already in the next commitfest, so if someone wants to add it as
an open 9.1 item, go ahead. I am unclear of this so I am not adding it.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +