How to use Java assertion in Hadoop MapReduce java API?

Question

for java program, we can use

java -ea

to enable assertion check. is it available in hadoop command:

hadoop jar some-mapreduce-program.jar org.foo.bar.MainJob ...

is it possible?

Answer 1

Assuming Hadoop 2+, you can set this property in your mapred-site.xml

<property>
    <name>mapreduce.map.java.opts</name>
    <value>-ea</value>
</property>

Alternatively, you can try exporting it in the client opts:

export HADOOP_CLIENT_OPTS="-ea ${HADOOP_CLIENT_OPTS}"
hadoop jar some-mapreduce-program.jar org.foo.bar.MainJob ...

Note that if you are using a cluster, this variable should be set in all nodes.