Archive for January, 2011|Monthly archive page

Baseball + Riak Map/Reduce, Round 2

If you enjoyed my last post on the Basho Blog, about computing baseball stats using Riak’s map/reduce, you may also enjoy my followup post about dealing with (or avoiding) records that have been split across block boundaries.

Baseball + Riak Map/Reduce

The luwak_mr tool I wrote about last weekend kept my imagination chugging this week. The result? I’ve learned a bit about baseball, and written code to compute batting average using luwak_mr (and Riak map/reduce, of course).

Learn how it works on the Basho Blog.

Map/reducing Luwak

I was inspired, this weekend, by off-list discussion of Luwak and by Guy Steele’s talk How to Think about Parallel Programming—Not!. The two seemed naturally attracted, and thus I created the luwak_mr module.

The luwak_mr module exposes simple a function that knows how to walk a Luwak file tree, and send the keys for each of its leaf nodes off to a Riak map/reduce process. This enables one to run a map function against each block in a luwak file. For example, one might split a large Latin-1 file into “words” (the luwak_mr_words module in the project is an example implementation of the method that Guy Steele presented).

And, yes, this blog has been dormant for a while … I’ve been busy. Lots of woodworking and travel. Making music has also begun to require more time, and yesterday I learned how to ski cross-country. Always busy, the life of a hobbyist.

Update: luwak_mr has also been accepted to the Riak function contrib. So if you’re in the habit of browsing there, fetch the latest.

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