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

[Florian Forster]

Hi Thorsten,

On Tue, Oct 30, 2007 at 04:18:22PM -0700, Thorsten von Eicken wrote:
> It looks like the network plugin doesn't re-resolve the hostname of a
> server ever.

that's right: The socket is opened once and then used as long as the
daemon lives.

> 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..

> 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.

Regards,
-octo
-- 
Florian octo Forster
Hacker in training
GnuPG: 0x91523C3D
http://verplant.org/
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