On 09/13/2016 02:15 AM, Bron Gondwana via Info-cyrus wrote:
On Tue, 13 Sep 2016, at 10:44, ellie timoney via Info-cyrus wrote:
Note that it talks about the process being used for new connections.
Each imapd process serves one connection at a time (so if you have 50
client connections, you will have 50 imapd processes to serve them, plus
whatever you have preforked ready to serve new connections). When one
of these connections disconnects, the imapd process that was serving
that connection goes back into the pool, ready to serve a new incoming
connection -- unless it has already served $uses connections, in which
case it exits, and master spawns a new one instead if necessary.
So you can see how, if you have mostly long-lived connections, each
imapd's count of how many connections it has served would grow very very
slowly -- many may not ever reach their limit, because you end up
needing to reboot the server (OS security updates, data centre works,
etc) before that occurs.
If you look in /var/lib/imap/proc/* you should see one file for each process id,
which tells you who is connected to that process, and which folder they have
selected (if any). This is quite useful for tracking down if there's a single user
causing issues.
Bron.
Bron, that was incredibly useful (FWIW, the proc list in Debian is at
/run/cyrus/proc/)
I took a look and our worst case server appears to have two users
(actually one user with two separate addresses) that are causing the
trouble. I restarted cyrus-imapd about 10 hrs ago and we are up to 28
imapd processes with start times all through the 10-hr block and they
all appear to be owned by one of two addresses as you can see here:
proc/10470:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/10473:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/11077:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/11257:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/11760:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/11810:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/12320:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/13065:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/13374:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/13376:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/13656:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/13764:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/13922:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/13944:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/14326:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/14506:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/17323:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/18363:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/8701:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/8705:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/8771:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/892:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/8960:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/9144:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/9197:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/943:imap donations@xxxxxxxxx cogift.co!user.donations Idle
proc/9584:imap b2b@xxxxxxxxx cogift.co!user.b2b Idle
proc/9800:imap donations@xxxxxxxxx cogift.co!user.donations Idle
So, given that all of these report as idle, should they not be shutting
down at some point?
I have the settings below in imapd.conf. My understanding of them is
after a connection has been idle for 15 min, try 5 tcp probes at 75 sec
intervals before marking the connection as broken.
tcp_keepalive: 1
tcp_keepalive_idle: 900
tcp_keepalive_cnt: 5
tcp_keepalive_intvl: 75
So is it possible that this client is responding to the tcp keepalive
packets so the idle connection is never shut down, but the client keeps
opening new connections when it wants to check email (which appears to
happen about every 10 - 15 minutes)?
I know this user so I will ask her what email client she is using and
how often it is set to check email.
Also, I see this note in cyrus.conf about idled...
# this is only necessary if idlemethod is set to "idled" in imapd.conf
idle cmd="idled"
But I can't find anything about idlemethod in any of the cyrus docs or
man pages. All I can find to set in imapd.conf for idle is the socket:
idlesocket: /var/run/cyrus/socket/idle
Hmmmmm...wait a minute...in looking for the Debian proc directory I came
across another idle socket created when I restarted cyrus-imapd.
srwxrwxrwx 1 root root 0 Sep 14 06:10 /run/cyrus/socket/idle
However, our imapd.conf specified a different idle socket which was also
created when cyrus-imapd was restarted.
srwxrwxrwx 1 root root 0 Sep 14 06:10 /var/run/cyrus/socket/idle
So I am thinking I should modify my imapd.conf idlesocket to
"/run/cyrus/socket/idle" which cyrus seems to be setting up anyway. Or
am I completely missing an obvious point here?
Sorry for being so clueless and thanks for all the help.
--
Andy Dorman
Ironic Design, Inc.
AnteSpam.com
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