Hi, On Mon, Aug 2, 2021, at 11:08, Alvaro Herrera wrote: > On 2021-Aug-02, Tom Lane wrote: > > > Robert Haas <robertmh...@gmail.com> writes: > > > If you're saying that this code has been 100% broken for 7 years and > > > nobody's noticed until now, then that suggests that nobody actually > > > uses non-shmem-connected bgworkers. I sort of hate to give up on that > > > concept but if we've really gone that many years without anyone > > > noticing obvious breakage then maybe we should. > > > > Well, the problem only exists on Windows so maybe this indeed > > escaped notice. Still, this is good evidence that the case isn't > > used *much*, and TBH I don't see many applications for it. > > I can't say I'm excited about putting effort into fixing it. > > When I included this case I was thinking in tasks which would just run > stuff not directly connected to data. Something like a sub-daemon: say > a connection pooler, which is a bgworker just so that it starts and > stops together with postmaster, and share facilities like GUC > configuration and SIGHUP handling, etc.
I think nearly all such cases are going to want some monitoring from within the database - which then needs shared memory. And even if not - it's not really that useful to avoid a crash-restart if your worker dies with a segfault. There's no really legitimate reasons for completely unhandled errors even if not connected to shmem. > It doesn't look like anybody > has had an interest in developing such a thing, so if this is > obstructing your work, I don't object to removing the no-shmem case. It's not obstructing me right now. I noticed it'd crash on EXEC_BACKEND when I tried to understand some code (see the nearby thread about straightening out process startup). I do think there's some potential gains in simplicity and robustness that are made mildly harder by a subprocess that first attaches and detaches from shm (it's the only case where we can't easily unify the place InitProcess() is called between EB and ! EB right now). There's several ways that could be tackled. Removing the need to have that if obviously one of them. Regards, Andres
