Show HN: Efficient data loading using zeta distributions

https://github.com/fed135/ha-store

by fed135 • 8 years ago

34 7 8 years ago

github.com

glifchits• 8 years ago

I would like to see more on the zeta distribution aspect of this, but it doesn't appear anywhere obvious in this repo.

Labo333• 8 years ago

Me too! Sometimes the HN titles have to overexagerate some mathy aspect to receive votes...

fed1353• 8 years ago

A man's gotta do... The zeta stuff is coming in my white paper real soon and will be summarized in https://github.com/fed135/ha-store/wiki

Cheers :)

vijay_nair2• 8 years ago

Few things I learned after a bit of research:

• the key to efficiency here seems to be “caching”, more specifically their caching strategy

• traditionally, caching on the web is done by assuming resource access follows the Zipf Distribution[1]

• Zeta Distributions are basically Zipf Distributions[2] so you can effectively re-word the title as “Efficient data loading using caching” (zipf = “caching” & zeta = zipf => zeta = “caching”)

• It’s important to note that Zipf/Zeta don’t model extremes very well, so there’s potential for outliers causing costly cache misses. Monitor your logs!

---

Further reading:

• https://pdfs.semanticscholar.org/337e/4b7f57ccbb7485950b93da... (1999)

• https://terrytao.wordpress.com/2009/07/03/benfords-law-zipfs...

• https://en.wikipedia.org/wiki/Zipf%27s_law

• https://www.springer.com/in/book/9781402080494

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[1] distribution follows a logarithm, so the most popular resource is accessed disproportionately more than the second most popular item and so on.

Example is word frequency, modeled as 1/n; second most popular word occurs 50% as much as the first most popular word (1/2), third most popular word occurs 33% as much as the first (1/3) and so on, showing an exponential falloff with a long tail. It thus makes sense to cache the first 10 most popular words as they are going to get accessed more than 90% of the time, giving you the efficiency. Basically this is a form of power law and similar to Pareto Distribution (20% of the things deliver 80% of the result)

[2] rigorously speaking, zeta is the normalized form of Zipf. But practically they are similar enough that people use the terms interchangeably.

fed1353• 8 years ago

Damn, it's like I don't even need to write the paper at all :) Great research work, it does capture the idea of the project.

Show HN: Efficient data loading using zeta distributions

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