[hobbit] /etc/resolv.conf and DNS error (http test)

[Dominique Frise]

Haertig, David F (Dave) wrote:
> Try adding a "search" line to resolv.conf.  e.g., "search example.com".
> Your existing domain line should set this as your default search, but
> maybe it's not?  Try explicitly setting it by adding a search line.  But
> you imply your problem is intermitant, so it's probably not default
> search that's getting you.  Do you get the same intermittant failures
> when you run "nslookup www.example.com" repeatedly from the command
> line?  I believe when you have multiple nameservers listed they are all
> queried, and the first to respond wins.  I don't think Solaris waits for
> the first to fail before moving on to the second like you say.  I'm not
> 100% sure about this though.
> 
> Note: I believe Solaris only uses the first six entries that are listed
> on a resolv.conf "search" line, ignoring the rest.  Something to keep in
> mind if you use this.
> 
> -----Original Message-----
> From: Dominique Frise [mailto:Dominique.Frise at unil.ch] 
> Sent: Wednesday, September 26, 2007 12:43 AM
> To: hobbit at hswn.dk
> Subject: [hobbit] /etc/resolv.conf and DNS error (http test)
> 
> Hi,
> 
> We have tried following settings in the Hobbit server's /etc/resolv.conf
> (Solaris 9)
> 
> domain example.com
> nameserver 1.2.3.4
> nameserver 1.2.3.5
> options timeout:1
> options retry:1
> 
> 
> While the first and second nameserver are up and running we receive
> sometimes "DNS error" on http checks like http://www.example.com.
> 
> Assuming that the first nameserver is not responding within the timeout,
> the second should be queried by the Hobbit resolver and get the
> response.
> 
> Is there something that we are missing?
> 
> 
> Dominique
> UNIL - University of Lausanne
> 
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> 

There are no intermittent problem while using nslookup or any other tool 
relying on the default resolver under Solaris.
I think the problem comes from the ARES resolver that Hobbit uses internally. 
Maybe the timeouts and retry setting are not interpreted the same way as the 
default resolver does.
I have no time to look at the code but perhaps Henrik has an answer...

Thanks.

Dominique