[ratelimits] results of responses/sec, slip and window size settings

[Gergely Bácskai]

Oops, I think I missed the attachments. Here they go.
Greg


2013/5/14 Gergely Bácskai <mor.mango at gmail.com>

> Yep, all queries were identical.
> I've read some documentation of the queryperf, it's a DNS-server
> performance measuring tool, shipped with BIND (as I know).
> From this info I think the "query/sec" was low because of my virtualbox,
> but I'm not sure about this..
>
> ...but this should not affect the count of success/failure. As I know,
> queryperf does not respond to the truncated responses. I'm not sure if it
> counts these as "successful responses", I'll look after it.
> I have set the logging in my BIND server, but the only log related to RRL
> I could find is in the "/var/log/named/bind-queries.log"
>
> I've made another try with 10 queries, and the RRL settings were: slip=2,
> resposnses-per-second=5, window=5, I've attached the results on 2 images:
> one is the queryperf result, and the other one is the bind-queries.log part
> of my action. Can somebody tell me from the attached bind log, how many
> queries were successful of the 10, so I can correlate it with the queryperf
> result?
>
> (Or maybe could anybody suggest a method that I can use to get the
> "expected" results of the mentioned RRL-settings?)
>
> Thanks,
> Greg
>
>
> 2013/5/10 Vernon Schryver <vjs at rhyolite.com>
>
>> > From: =?ISO-8859-1?Q?Gergely_B=E1cskai?= <mor.mango at gmail.com>
>>
>> > I set the RRL's window size to 5, responses-per-second to 5, and just
>> for
>> > sure, slip to 2.
>> >
>> > I have sent 1000 queries to the server with the queryperf script.
>> >
>> > The results are:
>> > 1000 queries, runtime: 131,8 sec, -->7.58 queries/sec
>> > ~50% success  ->3.8 successful queries/sec
>> >
>> > My two questions are:
>> > -how does the window size=5 affect in this example? (I've tried it with
>> > window=1, and got almost the same results, 57% success...)
>>
>> There is this text for the ARM:
>>
>>   Rate limiting uses a "credit" or "token bucket" scheme. Each
>>   identical response has a conceptual account that is given
>>   responses-per-second, errors-per-second, and nxdomains-per-second
>>   credits every second. A DNS request triggering some desired
>>   response debits the account by one. Responses are not sent while
>>   the account is negative. The account cannot become more positive
>>   than the per-second limit or more negative than window times the
>>   per-second limit. A DNS client that sends requests that are not
>>   answered can be penalized for up to window seconds (default 15).
>>
>> > -Shouldn't it act like:
>> > "I have 1000 queries, 131.8 sec runtime, so because of the
>> > responses-per-sec=5, every second it should be at first 5 successful
>> > queries -->5x131.8=659 successful queries at all minimum.
>> > But because of the slip=2, every second query of the rest 1000-659=341
>> > (about 170 queries) should be also successful.
>> > So at all, it should be 170+659=859 successful queries out of 1000?"
>> > ...And I don't even know how to count the window=5 for this....
>>
>> Were all of the queries identical?
>>
>> Does queryperf count "slipped" or truncated (TC=1) responses as
>> "successful"?  Does querfyperf react to truncated responses by
>> retrying with TCP?
>> I suspect queryperf is doing at least some retrying and delaying
>> for responses before sending more queries because 8 queries/second
>> is too slow for hardware made in this century.
>>
>> A test that sends 1000 queries in one second should receive 5 normal
>> response followed by 497 or 498 "slipped" or truncated (TC=1)
>> responses.
>>
>> The only good way I can see to answer such questions is to configure
>> BIND9 logging for the "queries" and "rate-limit" categories with a
>> debug level of at least 1, and look.  That will tell when BIND received
>> each query and what did.
>>
>>
>> Vernon Schryver    vjs at rhyolite.com
>> _______________________________________________
>> ratelimits mailing list
>> ratelimits at lists.redbarn.org
>> http://lists.redbarn.org/mailman/listinfo/ratelimits
>>
>
>
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