[HDFS-5584] Add OOB upgrade response and client-side logic for reads

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Later
• Component/s: datanode, ha, hdfs-client, namenode
• Assignee: Unassigned
• Reporter: Kihwal Lee
• Created: 02/Dec/13 16:46
• Updated: 13/Feb/14 13:42
• Resolved: 13/Feb/14 13:42

Description

Similarly to HDFS-5583, readers can also benefit from the knowledge that a data node failure is caused by an upgrade restart. Instead of permanently removing from the potential data source for the client, it could retry the node more times before declaring it dead.