[Mailman-Users] Problems with multi-machine slicing

[Jeff Taylor]

There is some load-balancing on the incoming side that splits messages 
between servers, but nothing on the outgoing side.  Mailman is run 
directly on each of the SMTP servers.  I started doing the slicing 
awhile back when I was having trouble with mailman crashing 
occasionally, and wanted to add more redundancy to ensure the out queue 
would get processed, even if it took a couple minutes for a backup 
machine to get to them.

On 05/25/2014 10:52 AM, Mark Sapiro wrote:
> On 05/24/2014 06:53 PM, Jeff Taylor wrote:
>> Its odd, I could have sworn the slicing used to be done per recipient,
>> not per message.  I've had to check logs for a client to confirm her
>> messages went out, and generally had check all three machines to verify
>> every user received the message.
>
> Mailman's outgoing message which includes the addresses of all
> recipients in the message's metadata is in one out/ queue entry.
> Whatever slice that's in, it will be picked up by the OutgoingRunner
> processing that slice of the queue and all recipients will be delivered
> to that runner's outgoing MTA (default on localhost).
>
> Perhaps there is also some load balancing between MTAs that allows them
> to share the delivery.
>