mapreduce远程调试

1. JVM本身就支持远程调试，Eclipse也支持JDWP，只需要在各模块的JVM启动时加载以下参数：

-Xdebug -Xrunjdwp:transport=dt_socket, address=8000,server=y,suspend=y

 

各参数的含义： -Xdebug 启用调试特性 -Xrunjdwp 启用JDWP实现，包含若干子选项： transport=dt_socket JPDA front-end和back-end之间的传输方法。dt_socket表示使用套接字传输。 address=8000 JVM在8000端口上监听请求，这个设定为一个不冲突的端口即可。 server=y y表示启动的JVM是被调试者。如果为n，则表示启动的JVM是调试器。 suspend=y y表示启动的JVM会暂停等待，直到调试器连接上才继续执行。suspend=n，则JVM不会暂停等待。

注意在工程里面改就可以了。。。。   xml version="1.0"?> xml-stylesheet type="text/xsl" href="configuration.xsl"?>     <configuration>     <property>         <name>mapred.job.trackername>         <value>192.168.1.219:9001value>     property>   <property> <name>mapred.child.java.optsname> <value>-agentlib:jdwp=transport=dt_socket,address=8883,server=y,suspend=yvalue> property>       <property>         <name>mapred.tasktracker.map.tasks.maximumname>         <value>1value>     property>     <property>         <name>mapred.tasktracker.reduce.tasks.maximumname>         <value>1value>     property>       <property>         <name>mapred.job.reuse.jvm.num.tasksname>         <value>-1value>     property> configuration>

在Eclipse中使用方法：   打开eclipse，找到Debug Configurations...，添加一个Remout Java Application: 在source中可以关联到hive的源代码,然后，单击Debug按钮进入远程debug模式。

 

HADOOP_NAMENODE_OPTS="-agentlib:jdwp=transport=dt_socket,address=8888,server=y,suspend=y" #HADOOP_SECONDARYNAMENODE_OPTS="-agentlib:jdwp=transport=dt_socket,address=8789,server=y,suspend=y" #HADOOP_DATANODE_OPTS="-agentlib:jdwp=transport=dt_socket,address=8790,server=y,suspend=y" #HADOOP_BALANCER_OPTS="-agentlib:jdwp=transport=dt_socket,address=8791,server=y,suspend=y" #HADOOP_JOBTRACKER_OPTS="-agentlib:jdwp=transport=dt_socket,address=8792,server=y,suspend=y" #HADOOP_TASKTRACKER_OPTS="-agentlib:jdwp=transport=dt_socket,address=8793,server=y,suspend=y"

 

 

 

对NameNode，SecondaryName，DataNode，JobTracker，TaskTracker进行远程调试，则需要修改一下bin/hadoop文件：   if [ "$COMMAND" = "namenode" ] ; then   CLASS='org.apache.hadoop.hdfs.server.namenode.NameNode'   HADOOP_OPTS="$HADOOP_OPTS $HADOOP_NAMENODE_OPTS -agentlib:jdwp=transport=dt_socket,address=8888,server=y,suspend=n"   elif [ "$COMMAND" = "secondarynamenode" ] ; then   CLASS='org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode'   HADOOP_OPTS="$HADOOP_OPTS $HADOOP_SECONDARYNAMENODE_OPTS -agentlib:jdwp=transport=dt_socket,address=8887,server=y,suspend=n"   elif [ "$COMMAND" = "datanode" ] ; then   CLASS='org.apache.hadoop.hdfs.server.datanode.DataNode'   HADOOP_OPTS="$HADOOP_OPTS $HADOOP_DATANODE_OPTS -agentlib:jdwp=transport=dt_socket,address=8886,server=y,suspend=n"   ……   elif [ "$COMMAND" = "jobtracker" ] ; then   CLASS=org.apache.hadoop.mapred.JobTracker   HADOOP_OPTS="$HADOOP_OPTS $HADOOP_JOBTRACKER_OPTS -agentlib:jdwp=transport=dt_socket,address=8885,server=y,suspend=n"   elif [ "$COMMAND" = "tasktracker" ] ; then   CLASS=org.apache.hadoop.mapred.TaskTracker   HADOOP_OPTS="$HADOOP_OPTS $HADOOP_TASKTRACKER_OPTS -agentlib:jdwp=transport=dt_socket,address=8884,server=y,suspend=n"

 

 

Namenode触发：

public DirectoryListing getListing(String src, byte[] startAfter) throws IOException { DirectoryListing files = namesystem.getListing(src, startAfter); myMetrics.incrNumGetListingOps(); if (files != null) { myMetrics.incrNumFilesInGetListingOps(files.getPartialListing().length); } return files; }

 

Secondnamenode

private void initialize(final Configuration conf) throws IOException { final InetSocketAddress infoSocAddr = getHttpAddress(conf); infoBindAddress = infoSocAddr.getHostName(); if (UserGroupInformation.isSecurityEnabled()) { SecurityUtil.login(conf, DFSConfigKeys.DFS_SECONDARY_NAMENODE_KEYTAB_FILE_KEY, DFSConfigKeys.DFS_SECONDARY_NAMENODE_USER_NAME_KEY, infoBindAddress); }

 

 

Datenode 触发：

DataNode(final Configuration conf, final AbstractList dataDirs, SecureResources resources) throws IOException { super(conf); SecurityUtil.login(conf, DFSConfigKeys.DFS_DATANODE_KEYTAB_FILE_KEY, DFSConfigKeys.DFS_DATANODE_USER_NAME_KEY);   datanodeObject = this; supportAppends = conf.getBoolean("dfs.support.append", false); this.userWithLocalPathAccess = conf .get(DFSConfigKeys.DFS_BLOCK_LOCAL_PATH_ACCESS_USER_KEY); try { startDataNode(conf, dataDirs, resources); } catch (IOException ie) { shutdown(); throw ie; } }

 

 

Jobtracker

 

public static JobTracker startTracker(JobConf conf, String identifier) throws IOException, InterruptedException {