[HDFS-11999] Ozone: Clarify startup error message of Datanode in case namenode is missing

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: HDFS-7240
• Fix Version/s: HDFS-7240
• Component/s: ozone
• Target Version/s: HDFS-7240
• Hadoop Flags: Reviewed
• Assignee: Marton Elek
• Reporter: Marton Elek
• Created: 19/Jun/17 21:52
• Updated: 24/Apr/18 20:52
• Resolved: 20/Jun/17 23:57

Description

Datanode is failing if namenode config setting is missing even for Ozone with a confusing error message:

14:33:29.176 [main] ERROR o.a.h.hdfs.server.datanode.DataNode - Exception in secureMain
java.io.IOException: No services to connect (NameNodes or SCM).
	at org.apache.hadoop.hdfs.server.datanode.BlockPoolManager.refreshNamenodes(BlockPoolManager.java:168) ~[classes/:na]
	at org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:1440) [classes/:na]
	at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:510) [classes/:na]
	at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:2802) [classes/:na]
	at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:2705) [classes/:na]
	at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:2752) [classes/:na]
	at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:2896) [classes/:na]
	at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:2920) [classes/:na]
14:33:29.177 [main] INFO  org.apache.hadoop.util.ExitUtil - Exiting with status 1: java.io.IOException: No services to connect (NameNodes or SCM).