Re: [Dovecot] stats plugins causing dns lookup per connection

2013-03-13 Thread Kelsey Cummings 
On 03/12/13 06:58, Axel Luttgens wrote:
 started for seemingly unrelated reasons, but ended with some form of cacheing 
 of the results fetched with gethostbyname().

It is a bit odd that it would totally block unless DNS requests on your
hosts weren't working at all - and even then, the requests would timeout
eventually and unblock.

 Which version of Dovecot are you running?

2.1.13

I see that caching is in 2.2 now too.  Timo, if there are any other
2.1.x releases it'd be nice to get this back ported to it as well.


-K

Re: [Dovecot] stats plugins causing dns lookup per connection

2013-03-12 Thread Axel Luttgens 
Le 12 mars 2013 à 05:51, Kelsey Cummings a écrit :

 I noticed our imap servers were generating a lot of A record lookups for
 their own IP's the other day and just got around to tracking down the
 source.  Seems like they are all being caused by guid_128_generate() -
 perhaps the lookup could be cached at start up or it could just use make
 use of the hostname rather than spending the effort to get the IP via
 gethostbyname() calls.  The function is used in a few other places too,
 so this might help more than just the stats plugin.

Hello Kelsey,

This one:

http://www.dovecot.org/list/dovecot/2013-February/088286.html

started for seemingly unrelated reasons, but ended with some form of cacheing 
of the results fetched with gethostbyname().

Which version of Dovecot are you running?

Axel

[Dovecot] stats plugins causing dns lookup per connection

2013-03-11 Thread Kelsey Cummings 
I noticed our imap servers were generating a lot of A record lookups for
their own IP's the other day and just got around to tracking down the
source.  Seems like they are all being caused by guid_128_generate() -
perhaps the lookup could be cached at start up or it could just use make
use of the hostname rather than spending the effort to get the IP via
gethostbyname() calls.  The function is used in a few other places too,
so this might help more than just the stats plugin.

nscd and/or host entries mitigate the total time spent on the lookup of
course, but it seems unnecessary.

-- 
Kelsey Cummings - k...@corp.sonic.net  sonic.net, inc.
System Architect  2260 Apollo Way
707.522.1000  Santa Rosa, CA 95407