[Mailman-Users] Mailman and multimaster redundancy

Mark Sapiro msapiro at value.net
Fri Nov 4 16:49:46 CET 2005


Ivan Fetch wrote:
>
>    However, you can't have two instances of Mailman running at the same 
>time, acting on the shared data storage (lists, archives, Etc) correct?

I'm not sure that you can't.

Concurrent updates to lists are protected by locks. I think there may
be an issue with queues. I believe it is possible (but a very small
window) for two concurrent qrunners processing the same slice of the
same queue to both pick up the same entry. This might be avoidable by
having the separate instances process different slices of the queues,
although this would probably require bin/mailmanctl changes. It may
also be avoidable by having each instance have it's own qfiles and
only sharing access to lists/, archives/ and locks/.

There is probably an issue with master-qrunner locks, and you'd
probably only run the crons on one instance. There is also an issue
with the data/ directory as held messages are stored there so it may
need to be shared too.

It may turn out to have too many gotchas, but I wouldn't rule it out
without investigating.

-- 
Mark Sapiro <msapiro at value.net>       The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan




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