启动NameNode报NullPointerException

标签：hadoop

在Hadoop版本0.20.1, 0.21.0 存在一个bug，NameNode同步失败，current产生了一个edits.new，和fsimage同步时又出现异常，而SecondNameNode也产生了同样的目录结构和数据，并报如下异常：

Our secondary name node is not able to start on NullPointerException:
ERROR org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode: java.lang.NullPointerException
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.unprotectedSetTimes(FSDirectory.java:1232)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.unprotectedSetTimes(FSDirectory.java:1221)
at org.apache.hadoop.hdfs.server.namenode.FSEditLog.loadFSEdits(FSEditLog.java:776)
at org.apache.hadoop.hdfs.server.namenode.FSImage.loadFSEdits(FSImage.java:992)
at
org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode$CheckpointStorage.doMerge(SecondaryNameNode.java:590)
at
org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode$CheckpointStorage.access$000(SecondaryNameNode.java:473)
at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.doMerge(SecondaryNameNode.java:350)
at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.doCheckpoint(SecondaryNameNode.java:314)
at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.run(SecondaryNameNode.java:225)
at java.lang.Thread.run(Thread.java:619)

This was caused by setting access time on a non-existent file.

修改Hadoop源码：

Index: src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
===================================================================
--- src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java	(revision 823221)
+++ src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java	(working copy)
@@ -33,6 +33,7 @@
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.server.common.HdfsConstants.StartupOption;
 import org.apache.hadoop.hdfs.server.namenode.BlocksMap.BlockInfo;
+import org.mortbay.log.Log;
 
 /*************************************************
  * FSDirectory stores the filesystem directory state.
@@ -1218,6 +1219,11 @@
   boolean unprotectedSetTimes(String src, long mtime, long atime, boolean force) 
                               throws IOException {
     INodeFile inode = getFileINode(src);
+    if (inode == null) {
+      NameNode.stateChangeLog.warn("DIR* FSDirectory.unprotectedSetTimes: "
+          +"failed to setTimes " + src + " because source does not exist");
+      return false;
+    }
     return unprotectedSetTimes(src, inode, mtime, atime, force);
   }

启动NameNode报NullPointerException

标签：hadoop

原文地址：http://blog.csdn.net/u012841509/article/details/45354389