We simply monitor established tcp sessions to smtpd port. if client flies away, tcp session does as well:
lsof -i tcp:25 | grep ESTABLISHED | wc -l Am Samstag, 20. Oktober 2018 schrieb Peer Heinlein : > > > > Hi, > > we're monitoring the amount of active smtpd processes to make sure, that > we do not reach the max-proc limit from master.cf. > > If a client disconnects very early, the smtpd is still "unused" and > remains in server memory, waiting for the next connection. > > If a server was flooded with a short peak of new connections, a server > could have $process_limit instances remaining ready-to-tun in memory. > > In that situations we're seeing false positives in our monitoring. > > I can't see a way how to detect those "waiting" smtpd to cound them > differently in the process list. AFAIK there's now way (except we're > counting the number of open connections with lsof/netstat). > > What about the idea that Postfix flags those unused processes by > renaming them in the output of "ps"? > > Dovecot has a "verbose proctitle" option where pop3/imap processes are > renamed in the process list so that they're showing the logged in user, > the state of TLS, the client IP and the last IMAP-command. > > It could also be very great to have Postfix like this, showing some > informations about the connection: > > smtpd [unused/virgin] > or > smtpd [<sasl_username>, <tls yes|no>, <client-ip>, <smtp_command>] > > Could be great for analysis and to get a quick overview about what's > going on on busy servers. > > Peer > > > -- > Heinlein Support GmbH > Schwedter Str. 8/9b, 10119 Berlin > > http://www.heinlein-support.de > > Tel: 030 / 405051-42 > Fax: 030 / 405051-19 > > Zwangsangaben lt. §35a GmbHG: HRB 93818 B / Amtsgericht > Berlin-Charlottenburg, > Geschäftsführer: Peer Heinlein -- Sitz: Berlin > >
