[Mailman-Developers] Re: Extraordinary locking mechanisms...
bwarsaw@python.org
bwarsaw@python.org
Wed, 10 May 2000 12:47:43 -0400 (EDT)
>>>>> "JH" == Jeremy Hylton <jeremy@cnri.reston.va.us> writes:
JH> Chris pointed at that mailman runs as a distributed system, so
JH> IPC won't work. The idea, though, of using something other
JH> than the filesystem for locking makes good sense. The locking
JH> could be based on a server that communication with other
JH> mailman components over a socket. It would look basically
JH> like the Javaspaces leasing service. (Leases are basically
JH> locks that timeout.) The only worry I would have is about
JH> crashes of the lease service. For a single machine, it could
JH> run under init; for multiple machines, a leader election
JH> protocol would be necessary to guard against machine crashes.
We also want to think about how all this will change if we move to a
monolithic daemon model, as opposed to the one-shot CGI model we're
currently using. We may not need external locks at that point at all
(although we'll of course still have to guard against crashes of that
daemon).
-Barry