[HDFS-13838] WebHdfsFileSystem.getFileStatus() won't return correct "snapshot enabled" status

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.1.0, 3.0.3
• Fix Version/s: 3.2.0, 3.0.4, 3.1.2
• Component/s: hdfs, webhdfs
• Target Version/s: 3.2.0, 3.1.1, 3.0.4
• Assignee: Siyao Meng
• Reporter: Siyao Meng
• Created: 21/Aug/18 00:01
• Updated: 02/Oct/19 17:15
• Resolved: 13/Sep/18 21:25

Description

"Snapshot enabled" status has been added in HDFS-12455 by Ajay Kumar.

However, it is found by [~jojochuang] that WebHdfsFileSystem.getFileStatus() won't return the correct "snapshot enabled" status. The reason is that JsonUtilClient.toFileStatus() did not check and append the "snapshot enabled" flag to the resulting HdfsFileStatus object.

Proof:

In TestWebHDFS#testWebHdfsAllowandDisallowSnapshots(), add the following lines indicated by prepending "+":

// allow snapshots on /bar using webhdfs
webHdfs.allowSnapshot(bar);
+// check if snapshot status is enabled
+assertTrue(dfs.getFileStatus(bar).isSnapshotEnabled());
+assertTrue(webHdfs.getFileStatus(bar).isSnapshotEnabled());

 
The first assertion will pass, as expected, while the second assertion will fail because of the reason above.

Update:

A further investigation shows that FSOperations.toJsonInner() also doesn't check the "snapshot enabled" bit. Therefore, "fs.getFileStatus(path).isSnapshotEnabled()" will always return false for fs type HttpFSFileSystem/WebHdfsFileSystem/SWebhdfsFileSystem. This will be addressed in a separate jira HDFS-13886.

Issue Links

• blocks: HDFS-13886 HttpFSFileSystem.getFileStatus() doesn't return "snapshot enabled" bit
• is caused by: HDFS-12455 WebHDFS - Adding "snapshot enabled" status to ListStatus query result.
• is caused by: HDFS-13141 WebHDFS: Add support for getting snasphottable directory list
• is related to: HDFS-13830 Backport HDFS-13141 to branch-3.0: WebHDFS: Add support for getting snasphottable directory list