[HDFS-7230] Add rolling downgrade documentation

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.0
• Fix Version/s: 2.6.0
• Component/s: documentation
• Hadoop Flags: Reviewed
• Assignee: Tsz-wo Sze
• Reporter: Tsz-wo Sze
• Created: 10/Oct/14 19:44
• Updated: 01/Dec/14 03:11
• Resolved: 30/Oct/14 17:52

Description

HDFS-5535 made a lot of improvement on rolling upgrade. It also added the cluster downgrade feature. However, the downgrade described in HDFS-5535 requires cluster downtime. In this JIRA, we discuss how to do rolling downgrade, i.e. downgrade without downtime.

Issue Links

• is related to: HDFS-7302 namenode -rollingUpgrade downgrade may finalize a rolling upgrade
• relates to: HDFS-5535 Umbrella jira for improved HDFS rolling upgrades