delayed response from pop3d

[Jon Rowell]

On Tuesday, March 11, 2003, at 01:40 PM, Sebastian Hagedorn wrote:

> -- Jon Rowell <jrowell at place.net> is rumored to have mumbled on 
> Dienstag, 11. März 2003 12:24 Uhr -0600 regarding Re: delayed response 
> from pop3d:
>
>> On Friday, March 7, 2003, at 12:40 PM, Rob Siemborski wrote:
>>
>>> On Fri, 7 Mar 2003, Jon Rowell wrote:
>>>
>>>> Since the upgrade, I am getting a delayed response from my pop3d.  I
>>>> have pop3 running on port 10110 and imap running on 10443 (as stated
>>>> in
>>>> cyrus.conf).  If I startup master and then do "telnet localhost 
>>>> 10110"
>>>> I get the usual telnet stuff about "connected to localhost" and
>>>> "Escape
>>>> character" but instead of getting the usual "+OK hostname Cyrus POP3
>>>> v2.1.12 server ready ..." stuff it just sits there.  The greeting
>>>> message does come up but it takes 5 minutes.  After the greeting 
>>>> comes
>>>> up, the server works fine.
>>>>
>>>> Imap appears to work fine.  There is a split second delay that I 
>>>> don't
>>>> remember being there but otherwise it is fine.
>>>
>>> Run the strace/truss equivilant on the processes and see whats taking
>>> them
>>> so long.
>>>
>>> Offhand, it sounds like a /dev/random problem (not enough entropy), 
>>> in
>>> which case the solution is to link /dev/urandom to /dev/random.
>>
>> Linking /dev/random to /dev/urandom fixed the problem but it made my
>> machine fail when it booted because of a device checking mechanism in 
>> the
>> boot process.
>>
>> Is there a way I can force cyrus to use /dev/urandom instead of
>> /dev/random?
>
> Hmm this sounds awfully similar to a problem I described this 
> afternoon, but:
>
> if I understand you correctly, you're not doing an SSL connection, are 
> you? If so, why should /dev/random make a difference? Also, *my* 
> version of Cyrus seems to be already using /dev/urandom (it appeared 
> later in the strace output). I haven't been able to reproduce this, 
> but I expect it to return after some time:
>

Correct.  I am not doing an ssl connection.  I'm not sure why 
/dev/random makes a difference but apparently it does.  According to 
truss, pop3d looks at /dev/random and then goes to sleep.  It will 
return eventually... 5 or 10 minutes later.  I find it odd that imapd 
does not behave the same way but it doesn't.

Jon Rowell

>> [root at lvr1 root]# pop3test -s -m PLAIN -a a0620 -u a0620 
>> pop.uni-koeln.de
>>
>> When I do that command, nothing happens for several minutes. I did an
>> strace on the process:
>>
>> [root at lvr1 root]# strace -p 9959
>> select(0, NULL, NULL, NULL, {0, 680000}) = 0 (Timeout)
>> select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
>> .... (many more lines like that)
>> open("/var/lib/imap/tls_sessions.db", 
>> O_RDWR|O_CREAT|O_EXCL|O_LARGEFILE,
>> 0664) = -1 EEXIST (File exists) brk(0x8097000)                        
>>   =
>> 0x8097000
>> time([1047377450])                      = 1047377450
>> getpid()                                = 9959
>>
>> From that point onwards everything is fine, but it takes literally
>> minutes to get there. Restarting master gets rid of the problem, but
>> that's not really a solution ;-)
> --
> Sebastian Hagedorn M.A. - RZKR-R1 (Flachbau), Zi. 18, Robert-Koch-Str. 
> 10
> Zentrum für angewandte Informatik - Universitätsweiter Service RRZK
> Universität zu Köln / Cologne University - Tel. 
> +49-221-478-5587<mime-attachment>