Re: Streaming replication, and walsender during recovery

On Mon, Jan 18, 2010 at 2:19 PM, Fujii Masao <masao.fujii@gmail.com> wrote:
> 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.

We got the consensus that the cascading standby feature should be
postponed to v9.1 or later. But when we wrongly make the standby
connect to another standby, the following confusing message is still
output.

    FATAL:  timeline 0 of the primary does not match recovery target timeline 1

How about emitting the following message instead? Here is the patch.

    FATAL:  recovery is in progress
    HINT:  cannot accept the standby server during recovery.

Regards,

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