Package org.apache.hadoop.hdfs.server.diskbalancer


package org.apache.hadoop.hdfs.server.diskbalancer
Disk Balancer connects to a .DataNode and attempts to spread data across all volumes evenly. This is achieved by : 1) Calculating the average data that should be on a set of volumes grouped by the type. For example, how much data should be on each volume of SSDs on a machine. 2) Once we know the average data that is expected to be on a volume we move data from volumes with higher than average load to volumes with less than average load. 3) Disk Balancer operates against data nodes which are live and operational.