Merging Block and BlockInfo classes on name-node.

• Key: HADOOP-1766
• Type: Improvement
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Konstantin Shvachko
• Reporter: Konstantin Shvachko
• Affects Version/s: 0.14.0
• Fix Version/s: 0.15.0

Description

In current implementation

• BlocksMap references BlockInfo
• INode references Block
• BlockInfo contains a reference to the corresponding Block

It would be better to incorporate Block into BlockInfo and reference the latter everywhere in name-node structures.
This saves 24 bytes per block on a 64-bit jvm as stated in HADOOP-1687 (5).
I retained the Block class as a structure for external (client and data-node) communication.