Does HBase MapReduce support a combiner stage? And if so, how?

Question

Hadoop map reduce supports a combiner stage. However, I can't find a similar capability in the HBase MapReduce package. Does it exist?

Answer 1

If you are running a MapReduce job with HBase as an input format and non-hbase output formats it is the same.

A combiner is a reducer that only operates on the output of a single mapper. As long as you only do things that are idempotent in your reducer, than you can put your reducer in the combiner slot by simply saying: job.setCombiner(.class);

Answer 2

You can use job.setCombiner(.class); method to use combiner class in map reduce. Reducer will aslso acts as an combiner