[AMBARI-16028] Namenode marked as INITIAL standby could potentially never start if other namenode is down

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.2.0
• Fix Version/s: 2.2-next
• Component/s: stacks
• Assignee: Jayush Luniya
• Reporter: Jayush Luniya
• Created: 21/Apr/16 22:12
• Updated: 17/Aug/16 07:54
• Resolved: 17/Aug/16 07:54

Description

Issue:

1. During Namenode HA blueprint deployment, we configure the name nodes to start in active/standby mode based on the following properties

        {
           "hadoop-env": {
             "properties" : {
               "dfs_ha_initial_namenode_active" : "host1",
               "dfs_ha_initial_namenode_standby" : "host2”
             }
           }
         }
   

2. The current logic is to always bootstrap the name node marked as standby.
3. This will lead to the Namenode marked as Standby to never start under the following situation

• Cluster is deployed successfully
• Both name nodes are stopped
• Start the name node marked as standby. Namenode will never start.
• This is because the standby name node will try to bootstrap again.
• However to bootstrap a name node an active name node is required. Based on the HDFS logic the first step done when bootstrapping is to connect to the Active Namenode.
• Also there is no need to bootstrap here as the name node should already be bootstrapped and should come back up as “Active"