根据这个http://www.thegeekstuff.com/2012/02/hadoop-pseudo-distributed-installation/网站尝试在我的笔记本电脑上以伪分发模式安装hadoop 0.21.0时，我遇到了这个例外来格式化namenode：
hadoop@host220:~/hadoop-0.21.0$ bin/hadoop namenode -format
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.
log4j:ERROR Could not instantiate class [org.apache.hadoop.log.metrics.EventCounter].
java.lang.ClassNotFoundException: org.apache.hadoop.log.metrics.EventCounter
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at org.apache.log4j.helpers.Loader.loadClass(Loader.java:179)
at org.apache.log4j.helpers.OptionConverter.instantiateByClassName(OptionConverter.java:320)
at org.apache.log4j.helpers.OptionConverter.instantiateByKey(OptionConverter.java:121)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:664)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:647)
at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurator.java:544)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:440)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:476)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:471)
at org.apache.log4j.LogManager.(LogManager.java:125)
at org.apache.log4j.Logger.getLogger(Logger.java:105)
at org.apache.commons.logging.impl.Log4JLogger.getLogger(Log4JLogger.java:289)
at org.apache.commons.logging.impl.Log4JLogger.(Log4JLogger.java:109)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.apache.commons.logging.impl.LogFactoryImpl.createLogFromClass(LogFactoryImpl.java:1116)
at org.apache.commons.logging.impl.LogFactoryImpl.discoverLogImplementation(LogFactoryImpl.java:914)
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:604)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:336)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:310)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685)
at org.apache.hadoop.conf.Configuration.(Configuration.java:153)
at org.apache.hadoop.hdfs.server.namenode.NameNode.(NameNode.java:137)
log4j:ERROR Could not instantiate appender named "EventCounter".
12/10/31 10:58:42 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = host220/127.0.0.1
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 0.21.0
STARTUP_MSG: classpath = /etc/hadoop:/usr/lib/jvm/java-6-sun/lib/tools.jar:/home/hadoop/hadoop-0.21.0/bin/../lib/*.jar
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.21 -r 985326; compiled by 'tomwhite' on Tue Aug 17 01:02:28 EDT 2010
************************************************************/
12/10/31 10:58:43 INFO namenode.FSNamesystem: defaultReplication = 3
12/10/31 10:58:43 INFO namenode.FSNamesystem: maxReplication = 512
12/10/31 10:58:43 INFO namenode.FSNamesystem: minReplication = 1
12/10/31 10:58:43 INFO namenode.FSNamesystem: maxReplicationStreams = 2
12/10/31 10:58:43 INFO namenode.FSNamesystem: shouldCheckForEnoughRacks = false
12/10/31 10:58:43 INFO security.Groups: Group mapping impl=org.apache.hadoop.security.ShellBasedUnixGroupsMapping; cacheTimeout=300000
12/10/31 10:58:43 INFO namenode.FSNamesystem: fsOwner=hadoop
12/10/31 10:58:43 INFO namenode.FSNamesystem: supergroup=supergroup
12/10/31 10:58:43 INFO namenode.FSNamesystem: isPermissionEnabled=true
12/10/31 10:58:43 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)
12/10/31 10:58:43 INFO common.Storage: Image file of size 112 saved in 0 seconds.
12/10/31 10:58:43 INFO common.Storage: Storage directory /tmp/hadoop-hadoop/dfs/name has been successfully formatted.
12/10/31 10:58:43 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at host220/127.0.0.1
************************************************************/
最后它成功地格式化了namenode，但有例外。 然后我尝试使用“start-all.sh”启动dfs和mapreduce，但失败了。以下是控制台输出：
hadoop@host220:~/hadoop-0.21.0$ bin/start-all.sh
This script is Deprecated. Instead use start-dfs.sh and start-mapred.sh
mkdir: cannot create directory `/var/run/hadoop': Permission denied
starting namenode, logging to /var/log/hadoop/hadoop/hadoop-hadoop-namenode-host220.out
/home/hadoop/hadoop-0.21.0/bin/../bin/hadoop-daemon.sh: line 127: /var/run/hadoop/hadoop-hadoop-namenode.pid: No such file or directory
log4j:ERROR Could not instantiate class [org.apache.hadoop.log.metrics.EventCounter].
java.lang.ClassNotFoundException: org.apache.hadoop.log.metrics.EventCounter
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
localhost: mkdir: cannot create directory `/var/run/hadoop': Permission denied
localhost: starting datanode, logging to /var/log/hadoop/hadoop/hadoop-hadoop-datanode-host220.out
localhost: /home/hadoop/hadoop-0.21.0/bin/hadoop-daemon.sh: line 127: /var/run/hadoop/hadoop-hadoop-datanode.pid: No such file or directory
localhost: log4j:ERROR Could not instantiate class [org.apache.hadoop.log.metrics.EventCounter].
localhost: java.lang.ClassNotFoundException: org.apache.hadoop.log.metrics.EventCounter
localhost: at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
localhost: at java.security.AccessController.doPrivileged(Native Method)
localhost: at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
localhost: at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
localhost: at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
localhost: at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
localhost: at java.lang.Class.forName0(Native Method)
localhost: at java.lang.Class.forName(Class.java:169)
localhost: mkdir: cannot create directory `/var/run/hadoop': Permission denied
localhost: starting secondarynamenode, logging to /var/log/hadoop/hadoop/hadoop-hadoop-secondarynamenode-host220.out
localhost: /home/hadoop/hadoop-0.21.0/bin/hadoop-daemon.sh: line 127: /var/run/hadoop/hadoop-hadoop-secondarynamenode.pid: No such file or directory
localhost: log4j:ERROR Could not instantiate class [org.apache.hadoop.log.metrics.EventCounter].
localhost: java.lang.ClassNotFoundException: org.apache.hadoop.log.metrics.EventCounter
localhost: at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
localhost: at java.security.AccessController.doPrivileged(Native Method)
localhost: at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
localhost: at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
localhost: at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
localhost: at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
localhost: at java.lang.Class.forName0(Native Method)
localhost: at java.lang.Class.forName(Class.java:169)
mkdir: cannot create directory `/var/run/hadoop': Permission denied
starting jobtracker, logging to /var/log/hadoop/hadoop/hadoop-hadoop-jobtracker-host220.out
/home/hadoop/hadoop-0.21.0/bin/../bin/hadoop-daemon.sh: line 127: /var/run/hadoop/hadoop-hadoop-jobtracker.pid: No such file or directory
log4j:ERROR Could not instantiate class [org.apache.hadoop.log.metrics.EventCounter].
java.lang.ClassNotFoundException: org.apache.hadoop.log.metrics.EventCounter
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
localhost: mkdir: cannot create directory `/var/run/hadoop': Permission denied
localhost: starting tasktracker, logging to /var/log/hadoop/hadoop/hadoop-hadoop-tasktracker-host220.out
localhost: /home/hadoop/hadoop-0.21.0/bin/hadoop-daemon.sh: line 127: /var/run/hadoop/hadoop-hadoop-tasktracker.pid: No such file or directory
localhost: log4j:ERROR Could not instantiate class [org.apache.hadoop.log.metrics.EventCounter].
localhost: java.lang.ClassNotFoundException: org.apache.hadoop.log.metrics.EventCounter
localhost: at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
localhost: at java.security.AccessController.doPrivileged(Native Method)
localhost: at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
localhost: at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
localhost: at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
localhost: at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
localhost: at java.lang.Class.forName0(Native Method)
localhost: at java.lang.Class.forName(Class.java:169)