[HADOOP-7896] HA: if both NNs are in Standby mode, client needs to try failing back and forth several times with sleeps

• Type: Sub-task
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: HA Branch (HDFS-1623)
• Fix Version/s: HA Branch (HDFS-1623)
• Component/s: ha, ipc
• Target Version/s: HA Branch (HDFS-1623)
• Hadoop Flags: Reviewed
• Assignee: Aaron Myers
• Reporter: Todd Lipcon
• Created: 08/Dec/11 05:51
• Updated: 29/Feb/12 13:05
• Resolved: 14/Dec/11 07:25

Description

For a manual failover, there may be an intermediate state for a non-trivial amount of time where both NNs are in standby mode. Currently, the failover proxy will immediately failover on receiving this exception from the first NN, and when it hits the same exception on the second NN, it immediately fails. It should probably fail back and forth nearly indefinitely if both NNs are in Standby mode.

Issue Links

• relates to: HDFS-2005 Client should not timeout during a NN start - esp useful for HA NN