[HDFS-16647] Delete unused NameNode#FS_HDFS_IMPL_KEY

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.3.3
• Fix Version/s: 3.4.0
• Component/s: namenode
• Labels: pull-request-available
• Hadoop Flags: Reviewed
• Assignee: JiangHua Zhu
• Reporter: JiangHua Zhu
• Created: 01/Jul/22 09:48
• Updated: 02/Jul/22 20:17
• Resolved: 02/Jul/22 20:17

Description

There's some history here, NameNode#FS_HDFS_IMPL_KEY was introduced in HDFS-15450, and something was removed later in HDFS-15533, but FS_HDFS_IMPL_KEY was kept.
Here are some discussion details:
https://github.com/apache/hadoop/pull/2229#discussion_r470935801

It seems to be cleaner to remove the unused NameNode#FS_HDFS_IMPL_KEY.

Issue Links

• is related to: HDFS-15533 Provide DFS API compatible class(ViewDistributedFileSystem), but use ViewFileSystemOverloadScheme inside
• links to: GitHub Pull Request #4525