[HDFS-29] In Datanode, update block may fail due to length inconsistency

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.21.0
• Component/s: datanode
• Hadoop Flags: Reviewed
• Assignee: Tsz-wo Sze
• Reporter: Tsz-wo Sze
• Created: 24/Apr/09 18:23
• Updated: 11/Apr/11 16:59
• Resolved: 14/Oct/09 00:26

Description

When a primary datanode tries to recover a block. It calls getBlockMetaDataInfo(..) to obtains information like block length from each datanode. Then, it calls updateBlock(..).

The block length returned in getBlockMetaDataInfo(..) may be obtained from a unclosed local block file F. However, in updateBlock(..), it first closes F (if F is open) and then gets the length. These two lengths may be different. In such case, updateBlock(..) throws an exception.

Issue Links

• is related to: HDFS-142 In 0.20, move blocks being written into a blocksBeingWritten directory