[HDFS-13493] Reduce the HttpServer2 thread count on DataNodes

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.1.0, 3.2.0, 3.0.3
• Component/s: datanode
• Target Version/s: 3.1.0, 3.0.3
• Hadoop Flags: Reviewed
• Assignee: Erik Krogen
• Reporter: Erik Krogen
• Created: 23/Apr/18 22:49
• Updated: 23/May/18 19:48
• Resolved: 23/May/18 19:14

Description

Given that HFTP was removed in Hadoop 3 and WebHDFS is handled via Netty, the HttpServer2 instance within the DataNode is only used for very basic tasks such as the web UI. Thus we can safely reduce the thread count used here.

Issue Links

• is depended upon by: HDFS-13265 MiniDFSCluster should set reasonable defaults to reduce resource consumption
• is related to: HDFS-13272 DataNodeHttpServer to have configurable HttpServer2 threads