October 2018
Beginner
220 pages
5h 33m
English
Content preview from Apache Hadoop 3 Quick Start Guide
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Intra-DataNode balancer
The need for a DataNode balancer arose for various reasons. The first is because, when a disk is replaced, the DataNodes need to be re-balanced based on available space. Secondly, with default round-robin scheduling available in Hadoop, mass file deletion from certain DataNodes leads to unbalanced DataNode storage. This was raised as JIRA issue HDFS-1312 (https://issues.apache.org/jira/browse/HDFS-1312), and it was fixed in Hadoop 3.0-alpha1. The new disk balancer supports reporting and balancing functions. The following table describes all available commands:
|
Command |
Parameters |
Description |
|
diskbalancer |
-plan <datanode> |
This command allows the user to create a plan (before/after) for a given DataNode. ... |
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