[Dovecot] Dovecot DNS queries its own host many times a second

[lst_hoe02 at kwsoft.de]

Zitat von Timo Sirainen <tss at iki.fi>:

> On 25.3.2013, at 3.07, Dominic Malolepszy  
> <dmalolepszy at optusnet.com.au> wrote:
>
>> We have observed that Dovecot appears to make a DNS lookup of its  
>> own hostname many times a second. Each Dovecot server in our  
>> cluster appears to be doing around 50 queries per second to find  
>> out its own hostname. Rsyslog was the first thing we assumed was  
>> the cause, however stopping it did not help. Also the fact that at  
>> the time Dovecot was doing around 50 logins a second, seemed to  
>> correlate with it making these queries. Is there any reason why  
>> Dovecot would need to do a lookup of its own hosts IP address every  
>> time? Seems like a strange thing to do and not cache its own  
>> hostname.
>
> I expected the libc to look it up from /etc/hosts directly.. Anyway,  
> v2.2 does such caching. I'm not sure if it's worth the trouble to  
> backport it to v2.1.

I guess this is dependant on content in /etc/nsswitch.conf at least on  
Linux, no?

Regards

Andreas