[HDFS-1405] Make FSVolumeSet in FSDataSet pluggable

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 0.22.0
• Component/s: datanode
• Assignee: Wang Xu
• Reporter: Wang Xu
• Created: 16/Sep/10 23:11
• Updated: 05/Dec/10 14:20
• Resolved: 05/Dec/10 14:20

Description

I am trying to submit a patch for HDFS-1362, which enable online add or remove a volume of a serving DataNode.

I managed to create the patch avoiding modify exist class, but FSVolumeSet is an exception, the member "volumes" is an array, while I need a List to facilitate the hotplug procedure. Thus I have 2 possible solutions:

• Provide a abstract class as its super class, with the definition of all its methods. OR
• Modify the volumes' definition in FSVolumeSet, as a Gereral Type Collection<>, which may use different implementation in subclasses.

I will supply a patch for the first method for review

Issue Links

• blocks: HDFS-1362 Provide volume management functionality for DataNode