[HDFS-5677] Need error checking for HA cluster configuration

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.6-alpha
• Fix Version/s: 2.3.0
• Component/s: datanode, ha

Environment

centos6.5, oracle jdk6 45,

• Assignee: Vincent Sheffer
• Reporter: Vincent Sheffer
• Created: 18/Dec/13 00:58
• Updated: 03/Sep/14 23:34
• Resolved: 14/Jan/14 22:07

Description

If a node is declared in the dfs.ha.namenodes.myCluster but is not later defined in subsequent dfs.namenode.servicerpc-address.myCluster.nodename or dfs.namenode.rpc-address.myCluster.XXX properties no error or warning message is provided to indicate that.

The only indication of a problem is a log message like the following:

WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Problem connecting to server: myCluster:8020

Another way to look at this is that no error or warning is provided when a servicerpc-address/rpc-address property is defined for a node without a corresponding node declared in dfs.ha.namenodes.myCluster.

This arose when I had a typo in the dfs.ha.namenodes.myCluster property for one of my node names. It would be very helpful to have at least a warning message on startup if there is a configuration problem like this.