4 ms·

Interesting, but what are long tail domain?

• theodorton 5y ago
  Domains that have less frequent lookups so the chance of getting a cached response is lower.
  • lloydatkinson 5y ago
    Why aren't they just called infrequently used domains then?
    • jasode 5y ago
      >Why aren't they just called infrequently used domains then? You could call them "infrequent" but "long-tail" is also a common description to convey a Power Law distribution: https://en.wikipedia.org/wiki/Long_tail https://en.wikipedia.org/wiki/Long_tail I think in this case about DNS caching, "long tail" is better than "infrequent". In the wikipedia graph, some of the domain lookups in yellow may be "frequent" (absolute sense) but simultaneously but much less popular (long tail) such that they don't stay in DNS lookup caches.
      • lloydatkinson 5y ago
        DNS is essentially a cache. I've never once in my life heard of infrequently accessed cache items as "long-tail". This is definitely a dumb phrase that should be avoided.
        • GauntletWizard 5y ago
          I've never heard them referred to as anything else, so YMMV
        • jasode 5y ago
          >I've never once in my life heard of infrequently accessed cache items as "long-tail". The parent poster wrote "long tail _domains_" and not cache items: https://news.ycombinator.com/item?id=29036188 https://news.ycombinator.com/item?id=29036188 You also used the word "domains" when you asked about "infrequently used domains" and that's the context I was responding to. I didn't say that cache items are labeled "long tail".
• wcoenen 5y ago
  I think the idea is that you take a list of all domains and then count the number of DNS lookups that are done for each over the course of some time period (e.g. 1 year). Then sort them from high to low number of lookups. At the start of the list you'll probably find only a few domains with many billions of lookups. As you go down the list you'll find many domains with very few lookups, the "long tail". It's a bit confusing because normally "long tail" refers to a histogram or probability distribution where a large portion of the population is far from the central part. I don't think that works in this case, unless I'm confused about what to put on the x-axis. (Because if the x-axis is lookup frequency, the domains being referred to here would be in a peak close to 0, not in the tail.) edit: maybe the x-axis of a histogram could be "mean time between lookups" instead of frequency? That would put the popular domains in the peak near 0, and the unpopular ones farther out in the "tail".
  • ranit 5y ago
    > what to put on the x-axis Perhaps 1/frequency.