In a previous thread
Subject: Re: iPhone/iPad IMAP connection bursts causes user+IP exceeded
I reported the behaviour of MacOSX/iOS IMAP readers whereby it would
use up all available connections (up to the mail_max_userip_connections
setting) for mailbox searches, then log them all out, then repeat the
cycle with another batch of mailbox searches, until all mailboxes were
scanned.
However, login/logout log counts don't square up. I would observe
(for a particular user+ip) mail_max_userip_connections login entries,
followed by *fewer* than mail_max_userip_connections logout entries.
(I could not find any disconnections or other forms of termination.)
The next peak connection count happened after another
mail_max_userip_connections logins (implying the total connection
count> mail_max_userip_connections), then another strings of logouts fewer
than mail_max_userip_connections.
For example, if mail_max_userip_connections=100, I would see
0 -> 100 logins -> 87 logouts -> 100 logins -> 87 logouts
-> 100 logins -> 94 logouts -> 100 logins -> ...
It appears that somewhere, somehow, IMAP session exits are not being
logged. Is there a reason to explain this discrepancy?
Joseph Tam <jtam.home at gmail.com>
