At Tue, 13 Jun 2023 14:38:14 -0700, Nathan Bossart <nathandboss...@gmail.com> wrote in > On Tue, Jun 13, 2023 at 04:28:31PM -0400, Tom Lane wrote: > > Nathan Bossart <nathandboss...@gmail.com> writes: > >> Before we spend too much time trying to document the current behavior, I > >> think we should see if we can change it to something less surprising (i.e., > >> failing to start if the server fails for any address). The original > >> objections around kernel support for IPv6 might no longer stand. > > > > I think that'd be more surprising not less. > > The reason it surprises me is because it creates uncertainty about the > server configuration. Granted, I could look in the logs for any warnings, > but I'm not sure that's the best experience. I would expect this to work > more like huge_pages. If I set huge_pages to "on", I know that the server > is using huge pages if it starts up. > > > The systemd guys certainly believe that daemons ought to auto-adapt > > to changes in the machine's internet connectivity. We aren't there > > yet, but I can imagine somebody trying to fix that someday soon. > > If the postmaster is able to dynamically acquire and drop ports then > > it would certainly not make sense to behave as you suggest. > > Agreed, if listen_addresses became a PGC_SIGHUP parameter, it would make > sense to avoid shutting down the server if it was dynamically > misconfigured, as is done for the configuration files. I think that > argument applies for changes in connectivity, too.
If I had to say, I would feel it rather surprising if server successfully starts even when any explicitly-specified port can't be opened (which is the current case). The current auto-adaption is fine iff I use '*' for listen_addresses. IMHO, for "reliable" auto-adaption, we might want '[+-]?xxx.xxx.xxx.xxx/nn' (and the same for v6), or '[+-]?interface-name' notation to require, allow, or disallow to use specific networks. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
