Re: [hobbit] bbtest shows long DNS runtime, why

["Josh Luthman" <josh (at) imaginenetworksllc.com>]

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

www.google.com 208.69.36.230 #   <-- this will lookup www.google.com and
ping the IP, if it can't find an A record for it then it will use the IP as
a backup

www.google.com 208.69.36.230 #   testip <--- this will use the hostname for
display purposes, no dns lookup and skip to using the IP for the conn test

I have the same triangular graphs on hotspot networks with multiple APs.
This is normal, as far as I can tell.

Adding 400 hosts and 400 dns queries shouldn't cause too much of a load,
though, if you're worried about the DNS queries taking out the DNS servers
then just tack "testip" to the end of them.  The conn/ping test is awfully
efficient, assuming you're using fping.

Are you using fping or hobbitping?

Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373

Those who don't understand UNIX are condemned to reinvent it, poorly.
--- Henry Spencer


On Fri, Sep 12, 2008 at 9:38 AM, <thorsten.erdmann (at) daimler.com> wrote:

>
> Hi
>
> I am running hobbit against 40 clients. Two of these clients are our DNS
> servers. Only on these two clients I have enabled the DNS test by adding the
> DNS keyword to their bb-hosts line. I wanted to check the function of the
> DNS servers
>
> If I look at the statistics of bbtest it looks like this:
>
> Fri Sep 12 15:26:08 2008
>
> bbtest-net version 4.2.0
> SSL library : OpenSSL 0.9.7a Feb 19 2003
> LDAP library: OpenLDAP 20213
>
> Statistics:
>  Hosts total           :       41
>  Hosts with no tests   :        1
>  Total test count      :       44
>  Status messages       :       45
>  Alert status msgs     :        0
>  Transmissions         :        2
>
> DNS statistics:
>  # hostnames resolved  :       40
>  # succesful           :       40
>  # failed              :        0
>  # calls to dnsresolve :       44
>
> TCP test statistics:
>  # TCP tests total     :        2
>  # HTTP tests          :        1
>  # Simple TCP tests    :        1
>  # Connection attempts :        2
>  # bytes written       :      126
>  # bytes read          :      871
>
>
> TIME SPENT
> Event                                            Starttime
>  Duration
> bbtest-net startup                       1221225968.275331
> -
> Service definitions loaded               1221225968.276931
>  0.001600
> Tests loaded                             1221225968.281365
>  0.004434
> DNS lookups completed                    1221225973.283037
>  5.001672
> Test engine setup completed              1221225973.285332
>  0.002295
> TCP tests completed                      1221225973.286398
>  0.001066
> PING test completed (40 hosts)           1221225974.166549
>  0.880151
> PING test results sent                   1221225974.177932
>  0.011383
> Test result collection completed         1221225974.177943
>  0.000011
> LDAP test engine setup completed         1221225974.177944
>  0.000001
> LDAP tests executed                      1221225974.177945
>  0.000001
> LDAP tests result collection completed   1221225974.177946
>  0.000001
> NSLOOKUP tests executed                  1221225974.179452
>  0.001506
> Test results transmitted                 1221225974.181039
>  0.001587
> bbtest-net completed                     1221225974.182936
>  0.001897
> TIME TOTAL
>  5.907605
>
>
> What you see are two mystic things:
>
> It seems that hobbit resolves all clients via DNS:
>   # hostnames resolved  :       40
> Why that, I gave all names and it's corresponding IPs at the bb-hosts file?
>
> The DNS test runs about 5 seconds for only these 40 clients, maybe that is
> because of the first issue:
>   DNS lookups completed                    1221225973.283037
>  5.001672
>
> If you look at the graph, it gives very scary "triagle curves". I've put a
> screenshot here: http://www.trektech.de/test/hobbitgraph.png
> The thing seems to have started when I put the DNS keyword to my two DNS
> servers. Before it gave a nearly zero line.
>
> I want to add about 400 network switches which should only do a ping test
> and I fear that this would extremely increase the runtime of the bbtest.
> What can I do to decrease the runtime?
>
> Thorsten Erdmann
> ITI/EP68
> Mercedes Benz Werk Hamburg
> Tel.: +49-40-7920-2593
>
>
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