On Tue, Jul 06, 2010 at 12:10:41PM -0700, Florin Andrei wrote:
> I realize that email delivery is not a trivial problem, but it seems
> baffling that a seemingly simple task ("fair" volume-based load balancing
> between transports) is so hard to achieve.
If you want to deliver the same number of messages to each server,
regardless of server performance, (message-count fairness, rather than
concurrency fairness), and suffer high latency when a slow server starts
to impede message flow, then turning off the cache will indeed give you
roughly uniform message distribution:
- *New* connections are distributed uniformly
- There is at most one delivery per connection
- Hence messages are distributed uniformly
However, concurrency will not be distributed uniformly, and a slow
server will account for most or all of the concurrency, ensuring a
high average latency even when alternative servers are sitting idle.
> I'll keep looking for a solution.
What negative symptoms are your systems exhibiting?
What *real* problem are you trying to solve?
--
Viktor.
