Last night we tried a traffic bypass in an existing mail environment before
migration to new Dovecot backend platfom using Dovecot proxy. We are using an
LDAP value for checking the proxy host of the user.
POP traffic was running flawlessly, but IMAP connections started to drop when
few clients connected:
Oct 17 22 :26:51 master: Warning: Sent SIGKILL to 100 imap-login processes
There are hundreds of these lines, always between 99 and 100 processes. Looks
like some kind of limit, but not sure if its related to the Dovecot proxy
machines (pool of 3 in total) or the final destination (the same IMAP server
for +10000 users). Concurrect IMAP connections may rise to around 2000.