Thanks, Sam -- I didn't think of it from this angle, makes perfect sense.
-Jeff On Apr 18, 2009, at 3:17 PM, Sam Varshavchik wrote: > J Potter writes: > >> Sam -- I've been seeing similar problems in the past few weeks on >> our servers. >> Would it be possible to have a config option for max idletime of >> an smtp connection? I.e., if no data comes in or goes out for a >> period of, say, 120 seconds, drop the connection and have the >> submit process exit? (Equivalent to Apache's "Timeout" setting.) > > The purpose of zombie spam senders is not to take as long as > possible to send their spam. That's absurd. They will try to get > through their spam load as quickly as possible. It's not that their > connections are idling. Courier is forcing them to spin their > wheels, through tarpitting. Look at the trace, the sender keeps > sending SMTP commands. It's the tarpitting that's slowing the sender > down. Were it not for tarpitting, in addition to all the connection > slots getting used up, you'd also have a sky-high CPU load. The > reason that strace shows activity only once every couple of minutes > is because Courier is explicitly tarpitting the senders. > > There is already a timeout setting: esmtptimeout (and > esmtptimeoutdata). I suspect that changing esmtptimeout from its > default value of 10 minutes to something smaller, like two minutes, > won't make any difference. Tarpitting doesn't count towards > timeouts. The maximum tarpit delay is two minutes. After two > minutes, the esmtptimeout clock starts, but the zombie sender has > already sent the next command. > > ------------------------------------------------------------------------------ > Stay on top of everything new and different, both inside and > around Java (TM) technology - register by April 22, and save > $200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco. > 300 plus technical and hands-on sessions. Register today. > Use priority code J9JMT32. > http://p.sf.net/sfu/p_______________________________________________ > courier-users mailing list > [email protected] > Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier- > users ------------------------------------------------------------------------------ Stay on top of everything new and different, both inside and around Java (TM) technology - register by April 22, and save $200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco. 300 plus technical and hands-on sessions. Register today. Use priority code J9JMT32. http://p.sf.net/sfu/p _______________________________________________ courier-users mailing list [email protected] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
