On Fri, 10 Feb 2017 14:59:51 -0800 (PST) Joseph Tam wrote:

"Rajesh M" <24x7server@24x7server.net> writes:

...

during peak times here are the results for connections

[root@ns1 domains]# doveadm who |grep imap |wc -l username # proto (pids) (ips) 631 [root@ns1 domains]# doveadm who |grep pop3 |wc -l username # proto (pids) (ips) 233

Thare are user counts, not connections. Ae a user can launch multiple IMAP connections, and if they have some MaxOSX reader, that can peak to several dozens during searches.

This counts connections

doveadm who | awk '/imap/{m+=$2}/pop3/{n+=$2}END{print m,n}'

Or you can parse the output of netstat.

I'm suprised you have so many POP3 connections though -- they tend to be connect/process/disconnect. n=0 most of the time on my modest server.

That vastly depends on things like client network speed and mailbox size. People pop'ing multi GB mailboxes (leave mail on server) with crappy clients (a big factor, some get disconnected for inactivity and thus hang around for 10 minutes) and over slow links tend to linger for quite a while.

Typical example:

Feb 11 13:54:27 mbx09 dovecot: pop3-login: Login: user=<redacted>, method=PLAIN, rip=redacted, lip=redacted, mpid=381958, secured, session=<FGtMAjpIpqpupZez> Feb 11 14:05:18 mbx09 dovecot: pop3(redacted): Disconnected: Logged out top=0/0, retr=0/0, del=0/6188, size=103540794 session=<FGtMAjpIpqpupZez>

This is on a server that's bored stiff when it comes to CPU usage or I/O utilization (pure SSD). All that twiddling of thumbs up there is purely client based.

Christian

Christian Balzer Network/Systems Engineer
chibi@gol.com Global OnLine Japan/Rakuten Communications http://www.gol.com/