Thanks Abhilash,
I'm a bit confused about dependency on local files? You mean files that are created when an e-mail is processed? So where is the problem with redundancy? If this host is gone there will be another Mailman deployment able to deal with the load.
What about having 3 VM where all components of Mailman are installed. Those VMs connect to 1 database on a remote host. We deploy HAProxy in front of 3VMs. So as the result all requests (HTTP/SMTP) are distributed to 1 VM (out of 3). A given VM handles a request HTTP or SMTP, and if there is a problem (or very high load of SMTP) there are still 2 other VM that can do the job. So perhaps the question is: can we plug 3 Mailman instances into 1 DB? Is Mailman software developed taking into account that several Mailman instance writes to the same database at the same time?
Cheers, Paweł