On Mon, Jul 21, 2008 at 12:47:25AM +0800, Uwe Dippel wrote:
> ... when a user has close to 20.000 mails in the Inbox.
> It chucks out courier-imap when  more processes are involved than allowed:
> (This is after some 3 hours of increasing load, searching around 1 GB in  
> cur:
>
> load averages: 84.11, 83.12, 80.77    21:04:01
> 10218 udippel  -14    0 3504K 4336K sleep    inode     0:00  0.88% imapd
> 5550 udippel   -5    0 3372K 1972K sleep    getblk    1:31  0.15% imapd
> 2566 udippel  -14    0 3368K 2080K sleep    inode     0:54  0.15% imapd
> 2623 udippel  -14    0 3296K 1892K sleep    inode     0:49  0.15% imapd
> 25935 udippel   -5    0 3504K 1872K sleep    getblk    0:47  0.15% imapd
> 21550 udippel  -14    0 3356K 1816K sleep    inode     0:27  0.15% imapd
> 30191 udippel  -14    0 3256K 1944K sleep    inode     0:24  0.15% imapd
> 14507 udippel  -14    0 3284K 2080K sleep    inode     0:54  0.10% imapd
> 28879 udippel   -5    0 3416K 1976K sleep    getblk    0:46  0.10% imapd
> 21472 udippel  -14    0 3368K 1972K sleep    inode     1:15  0.05% imapd
> 8937 udippel   -5    0 3404K 1792K sleep    getblk    0:48  0.05% imapd
> 20352 udippel  -14    0 3492K 1940K sleep    inode     0:15  0.05% imapd
> 11819 udippel  -14    0 3268K 1956K sleep    inode     0:14  0.05% imapd
> 15284 udippel  -14    0 3384K 1820K sleep    inode     1:38  0.00% imapd
> 21101 udippel  -14    0 3320K 1892K sleep    inode     1:34  0.00% imapd
> [,,,]
> ------------------------------------------------------------------------
>
> A moment later the thing is done:
>
> Mon Jun 30 21:09:35 SGT 2008
> /bin/ksh: cannot fork - try again
>
> I wrote to the courier-imap list, and Sam Varshavchik wrote:
>
> "imapd does not fork any processes. There is always a single process for  
> each
> login (and a second, if encryption is used). "
>
> I assume Sam knows. But why does OpenBSD fork like rabbits when a user  
> searches 'Entire Message' in a large mailbox?
>
> Uwe


We had a similar problem on our mailserver and thunderbird as mail client.
Basicly, thunderbird has a certain timeout  value for searches. If thunderbird
doesn't get a result for a search after <timeout> seconds, it assumes some
error and requests the search again. new search ->  new fork -> more load
and so on. Other MUAs may have similar settings. Solution:
Search and set the timeout value in thunderbird's config editor
(IRC mailnews.tcptimeout, defaults to 60)
Use smaller inboxes
Get more iron:)

Alf

Reply via email to