[HDFS-2521] Remove custom checksum headers from data transfer protocol

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.23.0
• Fix Version/s: 0.23.0
• Component/s: datanode, hdfs-client
• Target Version/s: 0.23.0
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon Assign to me
• Reporter: Todd Lipcon
• Created: 31/Oct/11 20:14
• Updated: 15/Nov/11 00:52
• Resolved: 01/Nov/11 05:17

Description

Most of the data transfer protocol has been converted over to protobufs, but we still send the checksum header with ad-hoc serialization in a few places. This is self-inconsistent and also makes wire protocol compatibility more difficult. This JIRA does the following:

• introduce a new protobuf message to describe a checksum
• include the "requested checksum" with the block operation (instead of coming separately after it)
• include the "required checksum" with the block operation response, for write operations (instead of coming first in the BlockSender stream)

Issue Links

• blocks: HDFS-2130 Switch default checksum to CRC32C