Chris Nauroth created HDFS-8432: ----------------------------------- Summary: Introduce a minimum compatible layout version to allow downgrade in more rolling upgrade use cases. Key: HDFS-8432 URL: https://issues.apache.org/jira/browse/HDFS-8432 Project: Hadoop HDFS Issue Type: Improvement Components: namenode, rolling upgrades Reporter: Chris Nauroth Assignee: Chris Nauroth
Maintain the prior layout version during the upgrade window and reject attempts to use new features until after the upgrade has been finalized. This guarantees that the prior software version can read the fsimage and edit logs if the administrator decides to downgrade. This will make downgrade usable for the majority of NameNode layout version changes, which just involve introduction of new edit log operations. -- This message was sent by Atlassian JIRA (v6.3.4#6332)