[Dovecot] imap process consuming 100% CPU (Dovecot 1.0.3)

[Jackie Hunt]

>:w On Mon, 2007-11-19 at 16:12 -0500, Stewart Dean wrote:
> > I think I'm seeing this with TBird and 1.0.7...with my own account!  It
> > may even be a Tbird problem.
> > I have a 4way mail server, so when I get 25%, it's 100% of one
> > processor. I tried killing the imap process on the server and  it can
> > back at 9% and climbed quickly back up to 25%.  It wasn't until I
> > shutdown my TBird session that a clean imap session was established.
> 
> You could truss the process or do something else to find out what
> Thunderbird and Dovecot are talking to each others. If shutting down
> Thunderbird dropped the load, it sounds like a bug in Thunderbird. Some
> clients have been known to keep requesting same data over and over again
> from the server in some situations. If I could see what the IMAP traffic
> looks like, I might be able to add a workaround to it.
> 

What Stewart describes sounds exactly like what we are seeing.  Killing the
imap process doesn't change anything, it requires the client to be shut down
to avoid using 100% CPU.  We have a user who was seeing this every morning.  
However, something has changed and he now sees it about every 7 to 10 days.  
Another interesting note is that he didn't see the issue when we were
running U of Wash's imap server.

Thanks for the suggestion on the truss command, Timo:

"truss -d -rO -w1"

I'll definitely post my results when I have some.

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