[HADOOP-1124] ChecksumFileSystem does not handle ChecksumError correctly

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.12.0
• Fix Version/s: 0.14.0
• Component/s: fs
• Assignee: Hairong Kuang
• Reporter: Hairong Kuang
• Created: 15/Mar/07 21:11
• Updated: 20/Aug/07 18:11
• Resolved: 12/Jul/07 17:51

Description

When handle ChecksumError, the checksumed file system tries to recover by rereading from a different replica.

I have three comments:
1. One bug in the code is that when retrying, the object that computes checksum does not get restored to the old state.
2. The code also assumes that the first byte read and the byte being read when ChecksumError occurs are in the same block.
3. It would be more efficient if we roll back to the first byte in the chunk that's being checksumed instead of rolling back to the first byte that was read.

Issue Links

• incorporates: HADOOP-1345 Checksum object does not get restored to the old state in retries when handle ChecksumException