On Sun, Sep 02, 2012 at 07:14:35PM +0100, Sam Jones wrote:
> I guess what I'm querying in a way is some of the sales blurb from
> people like PowerMTA & GreenArrow and the remarks they make about open
> source solutions like Postfix etc. This one in particular: "Open source
> Mail Transfer Agents (MTAs) often max out between 20 and 30 thousand
> messages per hour. GreenArrow can send 300,000 messages per hour?more
> than ten times as fast."
As I said, I measured 300 msgs/sec with Postfix on relatively modest
hardware in 2003. This is not too difficult, just configure sufficient
output concurrency, and provide a low latency disk (battery cache
striped RAID).
With RAM disk (a queue-manager bottleneck analysis, circa five
years ago) Postfix yielded ~3000 msgs/sec on a dual Opteron box
delivering to the discard transport. So that's your ceiling if you
provide sufficient disk and network bandwidth, eventually the queue
manager runs out of CPU, but this is at rates approaching 10 million
messages an hour.
The throughput numbers are not that interesting anymore, I go for
reliability, security and flexibility. I also go for a solid
architecture that degrades well under load, and that's why I
really like Postfix, but this is a difficult point to make,
most people are not in a position to understand why Postfix
stands out in this regard.
--
Viktor.
