Re: Streaming replication, and walsender during recovery

On Mon, 2010-01-18 at 09:31 -0500, Tom Lane wrote:
> Fujii Masao <masao(dot)fujii(at)gmail(dot)com> writes:
> > When I configured a cascaded standby (i.e, made the additional
> > standby server connect to the standby), I got the following
> > errors, and a cascaded standby didn't start replication.
>
> > ERROR: timeline 0 of the primary does not match recovery target timeline 1
>
> > I didn't care about that case so far. To avoid a confusing error
> > message, we should forbid a startup of walsender during recovery,
> > and emit a suitable message? Or support such cascade-configuration?
> > Though I don't think that the latter is difficult to be implemented,
> > ISTM it's not the time to do that now.
>
> It would be kind of silly to add code to forbid it if making it work
> would be about the same amount of effort. I think it'd be worth looking
> closer to find out what the problem is.

There is an ERROR, but no problem AFAICS. The tli isn't set until end of
recovery because it doesn't need to have been set yet. That shouldn't
prevent retrieving WAL data.

--
Simon Riggs www.2ndQuadrant.com