Cyrus lagging accepting IMAP connections

[Andy Fiddaman]

On Tue, 11 Sep 2007, Rick Kunkel wrote:

; # telnet mail 143
; Trying xxx.xxx.xxx.xxx...
; Connected to mail.
; Escape character is '^]'.
;
; And then it just kinda sits.  Sometimes, after 30 seconds or so
;
; * OK mail Cyrus IMAP4 v2.2.13-Debian-2.2.13-10 server ready

Generally this kind of delay is due to one of the following things:

o DNS problem
  The reverse DNS lookup is timing out for the client, or the server
  interface (if using virtualdomains).

o Insufficient entropy for sasl
  When a lot of users are connecting, sasl can block because it hasn't
  enough entropy - recompile SASL to use /dev/urandom instead of
  /dev/random.

o Linux 2.6 kernel
  Some people have reported this with Linux 2.6 and solved it by reverting
  to 2.4, I haven't seen any details on exactly what the problem is
  though..

HTH,

A.