Re: HS/SR and smart shutdown

Heikki Linnakangas wrote:
> It's a good question if that still makes sense with Hot Standby. Perhaps
> we should redefine smart shutdown in standby mode to shut down as soon
> as all read-only connections have died.
>

I've advocated in the past that an escalating shutdown procedure would
be helpful in general to have available. Start kicking off clients with
smart, continue to fast if there's any left, and if there's still any
left after that (have seen COPY clients that ignore fast) disconnect
them and go to immediate to completely kill them. Once you've started
the server on the road to shutdown, even with smart, you've basically
committed to going all the way down by whatever means is available
anyway, so why not make that more automated and easier.

If something like that were available, I could see inserting a step in
the middle there specifically aimed at resolving this issue. Maybe it's
just a change to the beginning of fast shutdown, or to the end of smart
as I think you're suggesting. Perhaps you only get it if you do one of
these escalating shutdowns I'm proposing, making that the preferred way
to handle HS servers.

--
Greg Smith 2ndQuadrant Baltimore, MD
PostgreSQL Training, Services and Support
greg(at)2ndQuadrant(dot)com www.2ndQuadrant.com