[Mailman-Users] Mailman and multimaster redundancy

[Ivan Fetch]

Hello,

    Hmm - I believe I remember mailmanctl being irritated about it's own 
locking when attempting to run a second instance of mailmanctl accessing 
the same Mailman data.  You can force lock removal, and perhaps the second 
instance would start, but I've never tried that (seemed like a bad idea). 
Perhaps it's time to setup a test bed.


Thanks - Ivan.

On Fri, 4 Nov 2005, Mark Sapiro wrote:

> 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
>
>