[HDFS-10208] Addendum for HDFS-9579: to handle the case when client machine can't resolve network path

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.9.0, 3.0.0-alpha1
• Hadoop Flags: Reviewed
• Assignee: Ming Ma
• Reporter: Ming Ma
• Created: 24/Mar/16 17:46
• Updated: 17/May/16 02:10
• Resolved: 17/May/16 02:01

Description

If DFSClient runs on a machine that can't resolve network path, DNSToSwitchMapping will return DEFAULT_RACK. In addition, if somehow dnsToSwitchMapping.resolve returns null, that will cause exception when it tries to create clientNode. In either case, there is no need to create clientNode and we should treat its network distance with any datanode as Integer.MAX_VALUE.

    clientNode = new NodeBase(clientHostName,
        dnsToSwitchMapping.resolve(nodes).get(0));

Issue Links

• relates to: HDFS-9579 Provide bytes-read-by-network-distance metrics at FileSystem.Statistics level