[collectd] network plugin doesn't re-resolve hostname ever

[Thorsten von Eicken]

Florian Forster wrote:
>> I have >300 hosts sending collectd data to a server and I need to move
>> the server to a different IP address. Right now it looks 
>> like I have to restart every single collectd daemon out there so it 
>> picks up the new DNS resolution for the server.
> 
> Yes, that's probably right.. Maybe you can first install some DNAT
> solution to send the packets to the new location and then use
> dssh <http://wunit.net/tech/dssh.html>,
> dsh  <http://www.netfort.gr.jp/~dancer/software/dsh.html.en> or
> something similar to restart the daemon on the hosts..

These are customer servers, so I can't simply log into each one and 
restart stuff...

>> IMHO collectd should re-resolve the server IP address every 5-10
>> minutes.
> 
> I'm not in love with this ``solution'': It adds quite some complexity
> (keeping track of time, getting the new socket addresses, special
> handling for when the lookup fails, checking if the currently used
> address is still in the list, possibly close and re-open the socket..)
> but not really any functionality. IP addresses usually don't change, the
> rare cases when they do change don't justify so much complexity and if
> you use the multicast functionality you don't have this problem in the
> first place.

Bummer. We're using this within Amazon EC2, so the IP address of the 
collectd server (actually soon more than one) changes every now and 
then, and multicast is not supported.

Looks like we have to hack this is ourselves then...

Thorsten