But, his project really was very reasonable:
- it fetched ~2,400 pages
- he cached them after first fetch
- Wikipedia aggressively caches anonymous page views (eg the Queen Elizabeth page has a cache age of 82,000 seconds)
English Wikipedia does about 250,000,000 pageviews/day. This guy's use was 0.001% of traffic on that day.
I get the slippery slope arguments, but to me, it just doesn't apply. As someone who has donated $1,000 to Wikipedia in the past, I'm totally happy to have those funds spent supporting use cases like this, rather than demanding that people who want to benefit from Wikipedia be able to set up a MySQL server, spend hours doing the import, install and configure a PHP server, etc, etc.
For 1 person consuming from one of the most popular sites on the web, this really reads big.
The 2,400 pages, assuming a 50 KB average gzipped size, equate to 120 MB of transfer. I'm assuming CPU usage is negligible due to CDN caching, and so bandwidth is the main cost. 120 MB is orders of magnitude less transfer than the 18.5 GB dump.
Instead of the dumps, he could have used the API -- but would that have significantly changed the costs to the Wikimedia foundation? I think probably not. In my experience, the happy path (serving anonymous HTML) is going to be aggressively optimized for costs, eg caching, CDNs, negotiated bandwidth discounts.
If we accept that these kinds of projects are permissible (which no one seems to be debating, just the manner in which he did the project!), I think the way this guy went about doing it was not actually as bad as people are making it out to be.
In theory, you'd want to cache more popular pages and let the rarely visited ones go through the uncached flow.
Crawling isn't user-behavior, so the odds are that a large percentage of the crawled pages were not cached.
Checking a random sample of 50 pages from this guy's dataset, 70% of them were cached.
This amount of activity really isn't something to worry about, especially when taking the fast path of logged out user viewing a likely to be cached page.
How is it possible that "give me all the infoboxes, please" is more than a single query, download, or even URL at this point?
Look at the template for a subway line infobox, for example. https://en.wikipedia.org/wiki/Template:Bakerloo_line_RDT
It's a whole little clever language (https://en.wikipedia.org/wiki/Wikipedia:Route_diagram_templa...) for making complex diagrams out of rather simple pictograms (https://commons.wikimedia.org/wiki/Template:Bsicon).
But every other infobox I've seen has key/value pairs where the key was always a string.
So what's the spec for an info box? Is it simply to have a starting `<table class="hello_i_am_infobox">` and an ending `</table>`?
If you want machine readable use wikidata (if you hate rdf you can still scrape the html preview of the data)
That plus a few other key things (categories, opening paragraph, redirects, pageview data) enable a lot of powerful analysis.
That actually might be kind of a neat thing to publish. Hmmmm.
Am I anywhere close to being correct?
The reason is that the dumps just have pointers to templates, and you need to understand quite a bit about Wikipedia's bespoke rendering system to know how to fully realize them (or use a constantly-evolving library like wtf_wikipedia [1] to parse them).
The rendered HTML, on the other hand, is designed for humans, and so what you see is what you get.
[1]: https://github.com/spencermountain/wtf_wikipedia