Re: boosting scalability, I've implemented it on thousands of machines, but not with mapreduce, rather with direct RPC calls. The gradient computation tends to be iterative, so one way to do it is to have each iteration run per mapreduce. Compute gradients in the mapper, gather them in the reducer, rinse and repeat.
I'll probably just implement an in-core variant first. re: online kernelized ranker - this is pretty easy to do so I will probably do it as a starter contribution. re: java, sure I have no problems writing it all in java. Whats the process in doing this? Write the code and them start a jiri ticket with the patch? -- Yee Yang Li Hector http://hectorgon.blogspot.com/ (tech + travel) http://hectorgon.com (book reviews)
