Set hadoop system user for client embedded in Java webapp

Question

I would like to submit MapReduce jobs from a java web application to a remote Hadoop cluster but am unable to specify which user the job should be submitted for. I would lik

Answer 1

Finally I stumbled on the constant

static final String HADOOP_USER_NAME = "HADOOP_USER_NAME";`

in the UserGroupInformation class.

Setting this either as an environment variable, as a Java system property on startup (using -D) or programmatically with System.setProperty("HADOOP_USER_NAME", "hduser"); makes Hadoop use whatever username you want for connecting to the remote Hadoop cluster.