[HDFS-11573] Support rename between different NameNodes in federated HDFS

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: federation
• Flags: Patch
• Assignee: Unassigned
• Reporter: zhouyingchao
• Created: 24/Mar/17 07:02
• Updated: 27/Jul/18 10:18

Description

Federated file system can improve overall scalability by dividing a single namespace into multiple sub-namespaces. Since the divided sub-namespace are held by different namenodes, rename operation between those sub-namespace is forbidden. Due to this restriction, many applications have to be rewritten to work around the issue after migrated to federated file system. Supporting rename between different namenodes would make it much easier to migrate to federated file systems.

We have finished a preliminary implementation of this feature in a 2.6 branch. I'll upload a write-up regarding the design in a few days. And then I'll re-org the code against the trunk and upload the patch.