Configure Map Side join for multiple mappers in Hadoop Map/Reduce

Question

I have a question about configuring Map/Side inner join for multiple mappers in Hadoop. Suppose I have two very large data sets A and B, I use the same partition and sort a

Answer 1

I think you're missing the point. You don't control the number of mappers. It's the number of reducers that you have control over. Simply emit the correct keys from your mapper. Then run 10 reducers.