[HDFS-1186] 0.20: DNs should interrupt writers at start of recovery

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.20-append
• Fix Version/s: 0.20.205.0
• Component/s: datanode
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 03/Jun/10 20:03
• Updated: 19/Oct/11 00:25
• Resolved: 03/Oct/11 21:48

Description

When block recovery starts (eg due to NN recovering lease) it needs to interrupt any writers currently writing to those blocks. Otherwise, an old writer (who hasn't realized he lost his lease) can continue to write+sync to the blocks, and thus recovery ends up truncating data that has been sync()ed.

Issue Links

• blocks: HBASE-2645 HLog writer can do 1-2 sync operations after lease has been recovered for split process.
• relates to: HDFS-1520 HDFS 20 append: Lightweight NameNode operation to trigger lease recovery