[hobbit] bbtest shows long DNS runtime, why

[Henrik Stoerner]

In <OF399C4BB5.DAE50E57-ONC12574C2.0049B7DF-C12574C2.004AD920 at dcx.dcx> thorsten.erdmann at daimler.com writes:

>What you see are two mystic things:

>It seems that hobbit resolves all clients via DNS:  =20
>  # hostnames resolved  :       40
>Why that, I gave all names and it's corresponding IPs at the bb-hosts=20
>file?

The IP's in the bb-hosts file are mostly there for backward compatibility
with Big Brother. Hobbit will do a DNS lookup to determine the IP-address,
and only if this fails will it fall back to using the IP listed in bb-hosts.

If you want to skip the DNS lookup, add a "testip" to the host lines in 
bb-hosts, or a "--dns=ip" option to the bbtest-net command in hobbitlaunch.cfg.


>I want to add about 400 network switches which should only do a ping test=20
>and I fear that this would extremely increase the runtime of the bbtest.
>What can I do to decrease the runtime?


Drop the DNS lookups of all hosts (see above), or run a local caching DNS
server on the Hobbit server. Hobbit does send a lot of DNS requests very
quickly, and I know from personal experience that some DNS servers have
problems with this.


Regards,
Henrik