[HDFS-7388] Improve the log for HA failover

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: ha
• Assignee: Jing Zhao
• Reporter: Jing Zhao
• Created: 10/Nov/14 23:32
• Updated: 06/Jan/17 22:03

Description

Currently to debug an issue during the NN HA failover (with automatic failover setup), we usually need to check log from all the NN and ZKFC daemons to figure out what triggered the failover. Possible reasons include NN health issue, connection issues between zkfc and NN, connection issues between zkfc and ZK, and manual op started by admin. It will be helpful to improve the log in NN and ZKFC and add more information to make the debug easier.