With the fix for
HDFS-11402, HDFS Snapshots can additionally capture all the open files. Just like all other files, these open files in the snapshots will remain immutable. But, sometimes it is found that snapshots fail to capture all the open files in the system.
Under the following conditions, LeaseManager will fail to find INode corresponding to an active lease
- a file is opened for writing (LeaseManager allots a lease), and
- the same file is deleted while it is still open for writing and having active lease, and
- the same file is not referenced in any other Snapshots/Trash
INode LeaseManager#getINodesWithLease() can thus return null for few leases there by causing the caller to trip over and not return all the open files needed by the snapshot manager.