[HDFS-1554] Append 0.20: New semantics for recoverLease

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.20-append, 0.20.205.0
• Hadoop Flags: Incompatible change, Reviewed
• Release Note: Change recoverLease API to return if the file is closed or not. It also change the semantics of recoverLease to start lease recovery immediately.
• Assignee: Hairong Kuang
• Reporter: Hairong Kuang
• Created: 22/Dec/10 23:13
• Updated: 19/Oct/11 00:26
• Resolved: 10/Jan/11 19:03

Description

Current recoverLease API implemented in append 0.20 aims to provide a lighter weight (comparing to using create/append) way to trigger a file's soft lease expiration. From both the use case of hbase and scribe, it could have a stronger semantics: revoking the file's lease, thus starting lease recovery immediately.

Also I'd like to port this recoverLease API to HDFS 0.22 and trunk since HBase is moving to HDFS 0.22.

Issue Links

• blocks: HBASE-2312 Possible data loss when RS goes into GC pause while rolling HLog
• is blocked by: HDFS-1555 HDFS 20 append: Disallow pipeline recovery if a file is already being lease recovered
• is depended upon by: HBASE-2312 Possible data loss when RS goes into GC pause while rolling HLog
• is related to: HDFS-1520 HDFS 20 append: Lightweight NameNode operation to trigger lease recovery
• relates to: HDFS-1948 Forward port 'hdfs-1520 lightweight namenode operation to trigger lease reccovery'