[HDFS-8914] Document HA support in the HDFS HdfsDesign.md

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.1
• Fix Version/s: 2.8.0, 2.7.3, 3.0.0-alpha1
• Component/s: documentation

Environment

Documentation page in live

• Target Version/s: 2.7.1
• Hadoop Flags: Reviewed
• Assignee: Lars Francke
• Reporter: Ravindra Babu
• Created: 18/Aug/15 12:10
• Updated: 30/Aug/16 01:29
• Resolved: 20/Jul/16 17:25

Description

Please refer to these two links and correct one of them.

http://hadoop.apache.org/docs/r2.7.1/hadoop-project-dist/hadoop-hdfs/HdfsDesign.html

The NameNode machine is a single point of failure for an HDFS cluster. If the NameNode machine fails, manual intervention is necessary. Currently, automatic restart and failover of the NameNode software to another machine is not supported.

http://hadoop.apache.org/docs/r2.7.1/hadoop-project-dist/hadoop-hdfs/HDFSHighAvailabilityWithQJM.html

The HDFS High Availability feature addresses the above problems by providing the option of running two redundant NameNodes in the same cluster in an Active/Passive configuration with a hot standby. This allows a fast failover to a new NameNode in the case that a machine crashes, or a graceful administrator-initiated failover for the purpose of planned maintenance.

Please update hdfsDesign article with same facts to avoid confusion in Reader's mind..