[HDFS-13021] Incorrect storage policy of snapshot file was returned by getStoragePolicy command

• Type: Bug
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.1.0
• Component/s: hdfs, snapshots
• Assignee: LiXin Ge
• Reporter: LiXin Ge
• Created: 15/Jan/18 12:01
• Updated: 27/Jan/18 06:54

Description

Snapshots are supposed to be immutable and read only, so the file status which in a snapshot path shouldn't follow the original file's change.

The StoragePolicy in snapshot situation acts like a bug now.

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Reproduction：Operation on snapshottable dir /storagePolicy

before make snapshot:

 [bin]# hdfs storagepolicies -setStoragePolicy -path /storagePolicy -policy PROVIDED
 Set storage policy PROVIDED on /storagePolicy

 [bin]# hadoop fs -put /home/file /storagePolicy/file_PROVIDED

 [bin]# hdfs storagepolicies -getStoragePolicy -path /storagePolicy/file_PROVIDED
 The storage policy of /storagePolicy/file_PROVIDED:
 BlockStoragePolicy{HOT:7, storageTypes=[DISK], creationFallbacks=[], replicationFallbacks=[ARCHIVE]}

make snapshot and check:

[bin]# hdfs dfs -createSnapshot /storagePolicy s3_PROVIDED
Created snapshot /storagePolicy/.snapshot/s3_PROVIDED

[bin]# hdfs storagepolicies -getStoragePolicy -path /storagePolicy/.snapshot/s3_PROVIDED/file_PROVIDED
The storage policy of /storagePolicy/.snapshot/s3_PROVIDED/file_PROVIDED:
BlockStoragePolicy{PROVIDED:1, storageTypes=[PROVIDED, DISK], creationFallbacks=[PROVIDED, DISK], replicationFallbacks=[PROVIDED, DISK]} 

change the StroagePolicy and check again:

[bin]# hdfs storagepolicies -setStoragePolicy -path /storagePolicy -policy HOT
Set storage policy HOT on /storagePolicy

[bin]# hdfs storagepolicies -getStoragePolicy -path /storagePolicy/.snapshot/s3_PROVIDED/file_PROVIDED
The storage policy of /storagePolicy/.snapshot/s3_PROVIDED/file_PROVIDED:
BlockStoragePolicy{HOT:7, storageTypes=[DISK], creationFallbacks=[], replicationFallbacks=[ARCHIVE]}   ---- It shouldn't be HOT