Hi all,

Our Dovecot server became non-responsive today and had to be restarted.
We had approximately 1200 imap sessions running, and when I looked at the log, I found the following errors:

Jan 16 10:02:01 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=75.166.40.150, lip=129.82.103.75, TLS handshake Jan 16 10:02:01 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=75.166.40.150, lip=129.82.103.75, TLS handshake Jan 16 10:02:12 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=75.166.40.150, lip=129.82.103.75, TLS handshake Jan 16 10:02:26 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=67.162.151.85, lip=129.82.103.75, TLS handshake Jan 16 10:02:26 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=129.82.100.135, lip=129.82.103.75 Jan 16 10:02:26 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=71.196.217.203, lip=129.82.103.75 Jan 16 10:02:26 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=129.82.100.135, lip=129.82.103.75 Jan 16 10:02:26 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=129.82.100.135, lip=129.82.103.75 Jan 16 10:02:26 lamar dovecot: imap-login: Disconnected: Connection queue full: rip=129.82.218.58, lip=129.82.103.75 ...

We are running v1.0.10 on AIX. Here's the relevant configuration from dovecot.conf:

# Set max. process size in megabytes. #login_process_size = 32

# Should each login be processed in it's own process (yes), or should one # login process be allowed to process multiple connections (no)? login_process_per_connection = no

# Number of login processes to keep for listening new connections. #login_processes_count = 3

# Maximum number of login processes to create. #login_max_processes_count = 128

# Maximum number of connections allowed per each login process. #login_max_connections = 256

We are running in the high-performance mode, where each login process can handle a number of connections. As I understand it that means we have login_max_connections * login_max_processes_count available possible logins at a given time. That's 32K with our configuration. That seems like a very high limit. Is that what these errors are indicating?

Thanks for any insight on this, Jackie

Jackie Hunt
ACNS Voice: (970) 663-3789
Colorado State University FAX: (970) 491-1958 Fort Collins, CO 80523 Email: jackie.hunt@colostate.edu