今天在执行sqoop往hbase里导数的时候,DN节点报了下面的错:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/yarn/exceptions/YarnRuntimeException at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2521) at java.lang.Class.getMethod0(Class.java:2764) at java.lang.Class.getMethod(Class.java:1653) at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:494) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:486) Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.yarn.exceptions.YarnRuntimeException at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 6 more
看异常是相应的jar没找到
为了执行MR,在yarn-site.xml中有这样一个的配置:
<property> <description>Classpath for typical applications.</description> <name>yarn.application.classpath</name> <value>$HADOOP_CONF_DIR,$HADOOP_COMMON_HOME/share/hadoop/common/*, $HADOOP_COMMON_HOME/share/hadoop/common/lib/*, $HADOOP_HDFS_HOME/share/hadoop/hdfs/*,$HADOOP_HDFS_HOME/share/hadoop/hdfs/lib/*, $YARN_HOME/share/hadoop/yarn/*,$YARN_HOME/share/hadoop/yarn/lib/*, $YARN_HOME/share/hadoop/mapreduce/*,$YARN_HOME/share/hadoop/mapreduce/lib/*</value> </property>
应该是这里的变量没有读到,导致这个原因应该是相应的环境变量没设置,
vi ~/.bashrc
增加:
export HADOOP_MAPRED_HOME=${HADOOP_HOME} export HADOOP_COMMON_HOME=${HADOOP_HOME} export HADOOP_HDFS_HOME=${HADOOP_HOME} export YARN_HOME=${HADOOP_HOME} export HADOOP_YARN_HOME=${HADOOP_HOME} export HADOOP_CONF_DIR=${HADOOP_HOME}/etc/hadoop export HDFS_CONF_DIR=${HADOOP_HOME}/etc/hadoop export YARN_CONF_DIR=${HADOOP_HOME}/etc/hadoop
这样设置以后,yarn-site.xml配置的变量就能读到相应的值,上述错误消失。