How to debug hadoop mapreduce jobs from eclipse?

Question

I\'m running hadoop in a single-machine, local-only setup, and I\'m looking for a nice, painless way to debug mappers and reducers in eclipse. Eclipse has no probl

Answer 1

Adding args to hadoop's internal java command can be done via HADOOP_OPTS env variable:

export HADOOP_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,address=5005,suspend=y"