Debugging Apache Spark can be tricky. Sure, everything works on your
--master local cluster, but not when run on a real cluster. In these cases, you need to drop to a debug breakpoint in the running cluster.
Get Debugger Listening
Simply update the launch args wherever you start Spark like so. Note:
SPARK_JAVA_OPTS won’t do the trick.
export SPARK_WORKER_OPTS="-Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=4000,suspend=n" export SPARK_MASTER_OPTS="-Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=4000,suspend=n" /opt/spark/sbin/start-master.sh
Open an SSH tunnel to your remote cluster machine, mapping
spark-master.foo.com:5000, assuming the cluster is at
spark-master.foo.com, listening on port
ssh -L localhost:4000:spark-master.foo.com:5000 email@example.com
Now Eclipse will think you’re just debugging a local Spark process.
Set Eclipse Breakpoint
git clone https://github.com/apache/spark.git git checkout v1.6.0
Now import the Spark
core module into ScalaIDE. There are a lot of modules, you only need
Set your breakpoint and create a Remote Java Application debugger config as shown below.
That’s it! Now you can debug on your live cluster as if it were your desktop.