Cyrus murder scalability

[Gary Mills]

On Thu, Oct 25, 2007 at 10:38:01AM -0400, Ken Murchison wrote:
> Vladimir Nikolic wrote:
> > 
> > I have questions regarding murder scalability. Untill last week we had 
> > one imap server with about 50000 users and 2TB mailboxes. Server was 
> > overloaded and little slow but there was no troubles like connections 
> > drop and repeatedly asking users for password.
> > Now we have that old server and three new servers in murder 
> > configuration (1 frontend, 1 murder master in 2 backends) and we have 
> > full troubles with users (almost all of them with pop3 accounts) 
> > complaining that mail clients repeatedly asking for password. Logs on 
> > fronted are full of lines:
> > 
> > pop3[12914]: couldn't authenticate to backend server
> > pop3[9822]: couldn't authenticate to backend server: authentication failure
> 
> What version of Cyrus?

I see these messages occasionally on the front end too.  This is with
cyrus 2.3.8.

> Do you only have this problem with POP3?  IMAP and LMTP connections are 
> proxied to the backends without any problems?

Ours are usually for IMAP.  I assumed that the session timed out for
idleness on the back end.  There's no corresponding message on the
back end.

    Oct 25 10:01:54 electra imap[12446]: [ID 637875 local6.error] Fatal error: Lost connection to selected backend
    Oct 25 10:02:11 electra imap[21715]: [ID 637875 local6.error] Fatal error: Lost connection to selected backend
    Oct 25 10:02:32 electra imap[29415]: [ID 637875 local6.error] Fatal error: Lost connection to selected backend

On the back end, these are common:

    Oct 25 09:36:34 castor pop3[8294]: [ID 390285 local6.error] Unable to lock maildrop user.shaykew: Mailbox is locked by POP server
    Oct 25 09:50:30 castor pop3[9277]: [ID 390285 local6.error] Unable to lock maildrop user.umpromo: Mailbox is locked by POP server
    Oct 25 09:52:40 castor pop3[8920]: [ID 390285 local6.error] Unable to lock maildrop user.harropp: Mailbox is locked by POP server

-- 
-Gary Mills-    -Unix Support-    -U of M Academic Computing and Networking-