[HDFS-4797] BlockScanInfo does not override equals(..) and hashCode() consistently

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.1.0-beta
• Component/s: datanode
• Hadoop Flags: Reviewed
• Assignee: Tsz-wo Sze
• Reporter: Tsz-wo Sze
• Created: 04/May/13 21:39
• Updated: 27/Sep/13 20:46
• Resolved: 01/Jul/13 01:30

Description

In the code below, equals(..) compares lastScanTime but hashCode() is computed using block ID. Therefore, it could have two BlockScanInfo objects which are equal but have two different hash codes.

//BlockScanInfo
    @Override
    public int hashCode() {
      return block.hashCode();
    }
    
    @Override
    public boolean equals(Object other) {
      return other instanceof BlockScanInfo &&
             compareTo((BlockScanInfo)other) == 0;
    }

Issue Links

• relates to: HDFS-5225 datanode keeps logging the same 'is no longer in the dataset' message over and over again