[hobbit] Which DNS query is causing delays

[Henrik Størner]

In <1F7B01020EC4D04DA17703634B9E888E0A01CCD1 at ULPGCTMVMAI003.EU.COLT> "Ward, Martin" <Martin.Ward at colt.net> writes:

>I have noticed recently that my bb-test runs are taking a long time to 
>complete, 6500 seconds instead of the maximum of 600. The info on the 
>bb-test results page shows that the DNS tests are taking most of the time, 
>but I have around 200 of these, does anyone have any suggestions on how 
>I can find out which DNS tests are causing the delays without having to 
>click on every DNS test in all of my Xymon website?

Are you using a local DNS cache ? I would strongly recommend that you
do - the resolver library in Xymon is pretty aggressive, and has been
known to knock out DNS servers if you have many hosts (although 200
doesn't sound like an awful lot).

It shouldn't take that long unless you're using the standard resolver
library (i.e. you are running bbtest-net with the "--no-ares" option),
in which case Xymon cannot control the timeout for the DNS lookup.

Try running with the option "--dnslog=FILENAME", this will log those 
DNS requests that fail. It is probably one of those.


Regards,
Henrik