Package org.apache.hadoop.hdfs.server.diskbalancer.connectors Description
Connectors package is a set of logical connectors that connect
 to various data sources to read the hadoop cluster information.
 We currently have 3 connectors in this package. They are
 DBNameNodeConnector - This uses the connector from the original
 balancer package to connect to a real hadoop cluster.
 JsonNodeConnector - This connects to a file and reads the data about a
 cluster. We can generate a cluster json from a real cluster using
 the diskBalancer tool or hand-craft it. There are some sample Json files
 checked in under test/resources/diskBalancer directory.
 NullConnector - This is an in-memory connector that is useful in testing.
 we can crate dataNodes on the fly and attach to this connector and
 ask the diskBalancer Cluster to read data from this source.