[HADOOP-12172] FsShell mkdir -p makes an unnecessary check for the existence of the parent.

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: fs
• Target Version/s: 2.8.0
• Hadoop Flags: Reviewed
• Assignee: Chris Nauroth
• Reporter: Chris Nauroth
• Created: 01/Jul/15 22:45
• Updated: 30/Aug/16 01:25
• Resolved: 02/Jul/15 02:54

Description

The mkdir command in FsShell checks for the existence of the parent of the directory and returns an error if it doesn't exist. The -p option suppresses the error and allows the directory creation to continue, implicitly creating all missing intermediate directories. However, the existence check still runs even with -p specified, and its result is ignored. Depending on the file system, this is a wasteful RPC call (HDFS) or HTTP request (WebHDFS/S3/Azure) imposing extra latency for the client and extra load for the server.