[HDFS-12985] NameNode crashes during restart after an OpenForWrite file present in the Snapshot got deleted

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.0
• Fix Version/s: 3.1.0, 2.10.0, 3.0.1
• Component/s: hdfs
• Target Version/s: 3.1.0, 2.10.0
• Assignee: Manoj Govindassamy
• Reporter: Manoj Govindassamy
• Created: 03/Jan/18 23:45
• Updated: 02/Oct/19 17:13
• Resolved: 09/Jan/18 00:22

Description

NameNode crashes repeatedly with NPE at the startup when trying to find the total number of under construction blocks. This crash happens after an open file, which was also part of a snapshot gets deleted along with the snapshot.

Failed to start namenode.
java.lang.NullPointerException
	at org.apache.hadoop.hdfs.server.namenode.LeaseManager.getNumUnderConstructionBlocks(LeaseManager.java:146)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getCompleteBlocksTotal(FSNamesystem.java:6537)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startCommonServices(FSNamesystem.java:1232)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.startCommonServices(NameNode.java:706)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:692)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:844)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:823)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1547)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1615)