Dear Viktor, Viktor Dukhovni <postfix-us...@dukhovni.org> writes:
> On Tue, Apr 26, 2022 at 11:54:21PM +0900, Byung-Hee HWANG wrote: > >> > There is obviously a point where the server won't be capable of >> > handling the load, always. But what are the odds with "just" a >> > brute-force on passwords/accounts? >> > Our outbound/internal mail gateway handles the traffic for +2K >> > every-day users +28K occasional users. Millions emails per month. It >> > handles also emails sent by applications. One of these app had a >> > problem last October and tried to send +2M emails per day, for many >> > days: the app authenticated on the mail server (sasl/dovecot) tried to >> > send the mail, got bounced because recipient was non-valid, got >> > disconnected, re-connected and tried again with next recipient, etc. >> > Nobody noticed, no user complained, no performance impact at all. We >> > only find out because of the postfix log volume increase. >> > It's a virtual machine with 4 vcpu and 10GB RAM (most ram is used by >> > antispam), it can handle way more: it runs postfix multi, does >> > antispam/av filtering and dkim singing for outbound, handles mailing >> > lists peaks of +60K messages, etc. >> >> Wow amazing story! Your email volume/traffic is a thousand times bigger than >> mine! > > Not surprising, when over a decade ago I set the Postfix servers for the > Google IPO, each individual server (spinning rust not SSD) was capable > of sustaining ~200 msgs/sec, which would be ~17M msgs/day if there were > enough messages. > > In the meantime the corporate mail servers were handling 2M messages/day > for ~80k users, for redundancy 4 nodes 2 each at 2 sites, any one would > have handled all the load. The main limiting factor was the CPU cost > of content inspection, "normal" mail processing easily scaled to > ~300/sec, but dropped to ~30/sec with content inspection. > > With SSD storage and modern CPUs, the peak performance of a Postfix > server would be a few times higher. Huwa... for a while i watched a movie like as <<Mission: Impossible>>! Thank you for sharing good story INDEED... Sincerely, Linux fan Byung-Hee -- ^고맙습니다 _布德天下_ 감사합니다_^))//
