[Dovecot] imap-login (proxy) Connection queue full

[Bill Boebel]

On Thu, August 10, 2006 11:15 pm, Bill Boebel <bill at webmail.us> said:

> On Thu, August 10, 2006 5:22 pm, Timo Sirainen <tss at iki.fi> said:
> 
>>> Aug 10 16:23:34 director5 dovecot: imap-login: Disconnected: Connection queue
>>> full:
>>>
>>> I am seeing this logged several times per minute.  From netstat, the server has
>>> 650 proxied IMAP connections and 450 proxied IMAPS connections, there are
>>> currently 10 imap-login processes running, and using the following config:
>>
>> I did some changes to CVS which hopefully should fix this?
> 
> It is still disconnecting with "Connection queue full", although less frequently. 
> Testing with about 315 IMAP connections right now and same config as earlier
> today, so it should never hit this condition, right?
> 
> The weird thing is sometimes when I am testing via telnet, my session encounters
> this condition and disconnects within the first 5 seconds.  It does this with and
> without these patches.

Here is another symptom:  The number of IMAP connections drops steeply repeatedly ever 30 seconds or so.  It does this only with the latest CVS (dovecot-20060811), not with the version I was testing previously (dovecot-20060808).

These were taken about 2 seconds apart:

# netstat -an | grep -c "192.168.1.69:143.*ESTA"
85
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
108
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
108
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
114
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
52
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
73
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
80
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
85
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
89
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
99
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
105
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
114
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
122
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
135
# netstat -an | grep -c "192.168.1.69:143.*ESTA"
32


# netstat -an | grep -c "192.168.1.69:993.*ESTA"
67
# netstat -an | grep -c "192.168.1.69:993.*ESTA"
69
# netstat -an | grep -c "192.168.1.69:993.*ESTA"
74
# netstat -an | grep -c "192.168.1.69:993.*ESTA"
83
# netstat -an | grep -c "192.168.1.69:993.*ESTA"
88
# netstat -an | grep -c "192.168.1.69:993.*ESTA"
95
# netstat -an | grep -c "192.168.1.69:993.*ESTA"
48


# lsof -nu dovecot |wc -l
616
# lsof -nu dovecot |wc -l
665
# lsof -nu dovecot |wc -l
690
# lsof -nu dovecot |wc -l
687
# lsof -nu dovecot |wc -l
706
# lsof -nu dovecot |wc -l
713
# lsof -nu dovecot |wc -l
735
# lsof -nu dovecot |wc -l
767
# lsof -nu dovecot |wc -l
803
# lsof -nu dovecot |wc -l
853
# lsof -nu dovecot |wc -l
891
# lsof -nu dovecot |wc -l
910
# lsof -nu dovecot |wc -l
933
# lsof -nu dovecot |wc -l
958
# lsof -nu dovecot |wc -l
575
# lsof -nu dovecot |wc -l
620
# lsof -nu dovecot |wc -l
629
# lsof -nu dovecot |wc -l
669
# lsof -nu dovecot |wc -l
701