On Thu, Mar 29, 2018, at 7:35 AM, Chris McMacken wrote:
After doing a lot of googling I can't seem to find solid answers to a couple of basic mailman hosting questions so I thought I would ask here.
I'm looking to build an auto scaling group so that my mailman services can self heal if the EC2 instance goes away. What state if any is stored locally on the filesystem that would need to be backed up and restored when an instance is replaced?
Maliman Core, the engine that sends and receives emails stores messages in queues on disk. Usually this is all inside "var" directory, but they may be scattered depending on where you install Mailman 3 from. So, you'd have to backup all those directories from the host.
Apart from that, Mailman Core and Django frontend all store most of their other data in a databases and you can backup-restore them using usual methods.
I'm also interested in a high availability deployment so I would like to do some basic load balancing to ensure that this requirement is met but I haven't been able to find much on this topic for mailman 3.
Since Core store some state on disk, it won't be possible to have multiple instances of Core serving the front-end. Front-end on the other-hand (based on Django) can easily be scaled and made to talk to a single Core as it stores everything in a Database that you can share across them.
Note that for now, Core expects to know the address for front-end (for archiving), and doesn't yet support multiple options there. So, you'd have to have one instance for receiving archived emails from Core and then others can just serve it.
-- Abhilash Raj maxking@asynchronous.in