On Wed, Feb 18, 2015 at 10:22 AM, Rob Seastrom <rs@seastrom.com> wrote:
The Pi is low-powered in more ways than one. Last fall I ran some (admittedly fairly simple minded) DNS benchmarks against a Raspberry Pi Model B and an ODROID U3.
Particularly if you have DNSSEC validation enabled, the Pi is underwhelming in performance (81 qps in the validation case, 164 without).
The U3 is circa 325 qps with or without DNSSEC validation on, which suggests that something else other than crypto-computes is the long pole in the tent.
Hi Rob, Interesting. The odroid has a 1700 mhz processor, the pi a 700 mhz processor. Except for the validation anomaly your results are self-consistent.
Caveats: This is just returning NXDOMAIN against a TLD for which (after the first run) there is already cached information that the TLD is bogus, so this test doesn't involve traffic actually leaving the box.
Given your testing methodology, the difference between validating and non-validating makes no sense to me. Once the records are cached bind should only be passing a flag around? Weird. On Wed, Feb 18, 2015 at 6:44 PM, Peter Loron <peterl@standingwave.org> wrote:
For any site where you would use a Pi as the DNS cache, it won't be an issue. DNS isn't that heavy at those query rates.
Yes and no. DNS is a lynchpin service. All connections stall until the DNS provides an IP address. So you kinda want low latency in your DNS lookups. If a fast server three hops away can respond faster than a slow server on the same LAN, the server three hops away is a better choice. A point in favor of the Raspberry Pi -- there's a heckuva lot of accessories already built for it. Including various cases and even a few different rackmount cases. And a wealth of "how do you do it?" and "why did it do this?" information available with just a few google search terms. The communities supporting the other hardware options are not nearly so large. Regards, Bill Herrin -- William Herrin ................ herrin@dirtside.com bill@herrin.us Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>