[HADOOP-8372] normalizeHostName() in NetUtils is not working properly in resolving a hostname start with numeric character

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.0, 0.23.0
• Fix Version/s: 2.0.2-alpha
• Component/s: io, util
• Hadoop Flags: Reviewed
• Assignee: Junping Du
• Reporter: Junping Du
• Created: 09/May/12 11:56
• Updated: 27/Nov/12 01:57
• Resolved: 09/May/12 23:18

Description

A valid host name can start with numeric value (You can refer RFC952, RFC1123 or http://www.zytrax.com/books/dns/apa/names.html), so it is possible in a production environment, user name their hadoop nodes as: 1hosta, 2hostb, etc. But normalizeHostName() will recognise this hostname as IP address and return directly rather than resolving the real IP address. These nodes will be failed to get correct network topology if topology script/TableMapping only contains their IPs (without hostname).

Issue Links

• is related to: HADOOP-9095 TestNNThroughputBenchmark fails in branch-1
• relates to: HADOOP-6824 Improve NetUtils:normalizeHostName