[HDFS-16685] DataNode registration fails because getHostName returns an IP address

• Type: Improvement
• Status: In Progress
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.4.0, 3.3.5
• Component/s: namenode

Environment

Run in Kubernetes using Java 11.  

• Target Version/s: 3.3.9
• Assignee: Steve Vaughan
• Reporter: Steve Vaughan
• Created: 25/Jul/22 14:30
• Updated: 29/Nov/22 15:51

Description

The call to dnAddress.getHostName() can return an IP address encoded as a string, which is then rejected because unresolved addresses can result in performance impacts due to repetitive DNS lookups later.  We can detect when this situation occurs, and perform a DNS reverse name lookup to fix the issue.

Bouncing a DataNode in a managed environment results in a new IP address allocation, and the new instance fails to register with the NameNode.

Issue Links

• is a child of: HADOOP-18396 Issues running in dynamic / managed environments