Re: [HACKERS] logical replication and PANIC during shutdowncheckpoint in publisher

On Tue, May 2, 2017 at 9:30 PM, Peter Eisentraut
<peter.eisentraut@2ndquadrant.com> wrote:
> On 5/2/17 03:11, Petr Jelinek wrote:
>> logical decoding can theoretically
>> do HOT pruning (even if the chance is really small) so it's not safe to
>> start logical replication either.
>
> This seems a bit impossible to resolve.  On the one hand, we want to
> allow streaming until after the shutdown checkpoint.  On the other hand,
> streaming itself might produce new WAL.

It would be nice to split things into two:
- patch 1 adding the signal handling that wins a backpatch.
- patch 2 fixing the side cases with logical decoding.

> Can we prevent HOT pruning during logical decoding?

It does not sound much difficult to do, couldn't you just make it a
no-op with am_walsender?
-- 
Michael