Major 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