[HDFS-7266] HDFS Peercache enabled check should not lock on object

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.7.0
• Fix Version/s: 2.7.0
• Component/s: hdfs-client
• Labels: multi-threading
• Target Version/s: 2.7.0
• Assignee: Andrew Wang
• Reporter: Gopal Vijayaraghavan
• Created: 20/Oct/14 14:10
• Updated: 10/Apr/15 20:30
• Resolved: 21/Oct/14 01:25

Description

HDFS fs.Open synchronizes on the Peercache, even when peer cache is disabled.

 public synchronized Peer get(DatanodeID dnId, boolean isDomain) {

    if (capacity <= 0) { // disabled
      return null;
    }

since capacity is a final, this could be moved outside the lock.