Just a friendly reminder that it should be named pipe rather than UDS ;)
-- igor
> Matthew Kirkwood <matthew@hairy.beasts.org> writes:
> >> ... and we already do it. But it protects the port number, not
> >> the data directory.
>
> > If I understood him correctly, Marc was suggesting a further
> > domain socket inside the data directory.
>
> Right, and that would work because we would reference it as
> $PGDATA/.socket --- exact, one-to-one correspondence between data
> directory and interlock file. A TCP socket isn't going to have any
> such direct connection to the data directory.
>
> We could try to make such a connection (eg, pick a free port number at
> random, and record the number in a lockfile in $PGDATA). But that will
> suffer from a bunch of failure modes, starting with the same one that's
> been biting us for PID interlocking: after a system restart, someone
> else may hold the port number that we chose at random last time.
>
> Basically, the reason that we want this interlock is because we are
> going after five-nines kind of reliability. An interlock technology
> that's not itself five-nines reliable isn't going to make things better.
>
> regards, tom lane
>
