Hadoop Configuration

Every node in the Hadoop cluster must have a copy of the configuration files, including the client nodes. The configurations in the file are applied as follows (in the order of highest to lowest):

1. Values specified in the JobConf or Job object when initializing the MapReduce job
2. *-site.xml on the client node
3. *-site.xml on the slave node
4. Default values from the *-default.xml, which are the same on all the nodes