[HDFS-532] Allow applications to know that a read request failed because block is missing

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.21.0
• Component/s: hdfs-client
• Hadoop Flags: Reviewed
• Assignee: Dhruba Borthakur
• Reporter: Dhruba Borthakur
• Created: 06/Aug/09 19:32
• Updated: 24/Aug/10 20:48
• Resolved: 13/Aug/09 18:11

Description

I have an application that has intelligence to retrieve data from alternate locations if HDFS cannot provide this data. This can happen when data in HDFS is corrupted or the block is missing. HDFS already throws ChecksumException if the block is corrupted and throws a generic IOException if the block is missing. I would like HDFS to throw BlockMissingException when a read request encounters a block that has no locations associated with it.