Re: Pause/Resume feature for Hot Standby

Simon Riggs <simon(at)2ndQuadrant(dot)com> writes:

> In the original patch I had Pause/Resume feature for controlling
> recovery during Hot Standby. It was removed for lack of time.
>
> With all the discussion around the HS UI, it would be something that
> could be back very easily.

Please!

Manual control over recovery is the best solution ever proposed for
giving the user explicit control over the trade-off between HA and slave
queries.

It would allow us to say that by default, conflict favors WAL recovery
no matter what. If you want to ensure your queries won't get canceled,
pause the recovery, run your report, resume the recovery.

I understand that automated and flexible conflict resolution still is
needed or wanted even with this UI, but that would allow a much more
crude automated tool to be acceptable. Specifically, it could only
target short queries on the standby, for long running queries you don't
want to get cancelled, pause the recovery.

Regards,
--
dim