最近一直在自学Hadoop，今天花点时间搭建一个开发环境，并整理成文。

首先要了解一下Hadoop的运行模式：

单机模式（standalone）
   单机模式是Hadoop的默认模式。当首次解压Hadoop的源码包时，Hadoop无法了解硬件安装环境，便保守地选择了最小配置。在这种默认模式下所有3个XML文件均为空。当配置文件为空时，Hadoop会完全运行在本地。因为不需要与其他节点交互，单机模式就不使用HDFS，也不加载任何Hadoop的守护进程。该模式主要用于开发调试MapReduce程序的应用逻辑。
伪分布模式（Pseudo-Distributed Mode）
   伪分布模式在“单节点集群”上运行Hadoop，其中所有的守护进程都运行在同一台机器上。该模式在单机模式之上增加了代码调试功能，允许你检查内存使用情况，HDFS输入输出，以及其他的守护进程交互。
   全分布模式（Fully Distributed Mode）
1.安装JDK，并指定系统默认jdk为oracle的版本，默认安装到的目录为/usr/java/jdk1.7.0_45 ，下文将其设置为JAVA_HOME
rpm -ivh jdk-7u51-linux-i586.rpm

vim hdfs-site.xml

这里是对namenode和daatanode存储路径的设置。

vim mapred-site.xml


最后在hadoop-env.sh 这个文件中加入jdk的指定，在文件最后加入export JAVA_HOME=/usr/java/jdk1.7.0_45 也就是你的jdk目录
4.启动hadoop，进入默认安装目录，首先要对namenode进行格式化，进入bin目录里
./hdfs namenode -format
14/03/24 15:18:29 INFO namenode.NameNode: STARTUP_MSG: 
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG:   host = hadoop/192.168.47.74
STARTUP_MSG:   args = [-format]
STARTUP_MSG:   version = 2.2.0
STARTUP_MSG:   classpath = /hadoop/hadoop-2.2.0/etc/hadoop:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/stax-api-1.0.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/junit-4.8.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-codec-1.4.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jaxb-impl-2.2.3-1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jersey-core-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/log4j-1.2.17.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/paranamer-2.3.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-beanutils-core-1.8.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/mockito-all-1.8.5.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jersey-json-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/hadoop-annotations-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jets3t-0.6.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/slf4j-log4j12-1.7.5.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-beanutils-1.7.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-collections-3.2.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-io-2.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jackson-core-asl-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jsch-0.1.42.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/servlet-api-2.5.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/asm-3.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jasper-compiler-5.5.23.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/snappy-java-1.0.4.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-httpclient-3.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jaxb-api-2.2.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/netty-3.6.2.Final.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/guava-11.0.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/xz-1.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/activation-1.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jackson-jaxrs-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-net-3.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jsr305-1.3.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/xmlenc-0.52.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-configuration-1.6.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-digester-1.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jasper-runtime-5.5.23.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-logging-1.1.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jackson-mapper-asl-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/hadoop-auth-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jsp-api-2.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jackson-xc-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/protobuf-java-2.5.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/avro-1.7.4.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-math-2.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-lang-2.5.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/slf4j-api-1.7.5.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-cli-1.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/zookeeper-3.4.5.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-el-1.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jetty-util-6.1.26.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/commons-compress-1.4.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jettison-1.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jetty-6.1.26.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/lib/jersey-server-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/hadoop-common-2.2.0-tests.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/hadoop-common-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/common/hadoop-nfs-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/commons-codec-1.4.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jersey-core-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/log4j-1.2.17.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/commons-io-2.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jackson-core-asl-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/servlet-api-2.5.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/asm-3.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/netty-3.6.2.Final.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/guava-11.0.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/commons-daemon-1.0.13.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jsr305-1.3.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/xmlenc-0.52.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jasper-runtime-5.5.23.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/commons-logging-1.1.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jackson-mapper-asl-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jsp-api-2.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/protobuf-java-2.5.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/commons-lang-2.5.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/commons-cli-1.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/commons-el-1.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jetty-util-6.1.26.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jetty-6.1.26.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/lib/jersey-server-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/hadoop-hdfs-2.2.0-tests.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/hadoop-hdfs-nfs-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/hdfs/hadoop-hdfs-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/aopalliance-1.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/jersey-core-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/log4j-1.2.17.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/paranamer-2.3.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/hadoop-annotations-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/javax.inject-1.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/commons-io-2.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/jackson-core-asl-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/hamcrest-core-1.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/asm-3.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/junit-4.10.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/snappy-java-1.0.4.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/netty-3.6.2.Final.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/xz-1.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/jersey-guice-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/guice-3.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/jackson-mapper-asl-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/protobuf-java-2.5.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/avro-1.7.4.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/guice-servlet-3.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/commons-compress-1.4.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/lib/jersey-server-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-server-nodemanager-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-applications-unmanaged-am-launcher-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-server-tests-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-server-common-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-server-resourcemanager-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-client-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-server-web-proxy-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-common-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-applications-distributedshell-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-api-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/yarn/hadoop-yarn-site-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/aopalliance-1.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/jersey-core-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/log4j-1.2.17.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/paranamer-2.3.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/hadoop-annotations-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/javax.inject-1.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/commons-io-2.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/jackson-core-asl-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/hamcrest-core-1.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/asm-3.2.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/junit-4.10.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/snappy-java-1.0.4.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/netty-3.6.2.Final.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/xz-1.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/jersey-guice-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/guice-3.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/jackson-mapper-asl-1.8.8.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/protobuf-java-2.5.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/avro-1.7.4.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/guice-servlet-3.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/commons-compress-1.4.1.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/lib/jersey-server-1.9.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-client-jobclient-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-client-jobclient-2.2.0-tests.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-client-hs-plugins-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-client-shuffle-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-client-hs-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-client-common-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-client-core-2.2.0.jar:/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/hadoop-mapreduce-client-app-2.2.0.jar:/hadoop/hadoop-2.2.0/contrib/capacity-scheduler/*.jar
STARTUP_MSG:   build = https://svn.apache.org/repos/asf/hadoop/common -r 1529768; compiled by 'hortonmu' on 2013-10-07T06:28Z
STARTUP_MSG:   java = 1.7.0_51
************************************************************/
14/03/24 15:18:29 INFO namenode.NameNode: registered UNIX signal handlers for [TERM, HUP, INT]
14/03/24 15:18:29 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
14/03/24 15:18:30 WARN common.Util: Path /dfs/name should be specified as a URI in configuration files. Please update hdfs configuration.
14/03/24 15:18:30 WARN common.Util: Path /dfs/name should be specified as a URI in configuration files. Please update hdfs configuration.
Formatting using clusterid: CID-27a0d847-6b78-4748-abd9-a78e970f18e7
14/03/24 15:18:30 INFO namenode.HostFileManager: read includes:
HostSet(
)
14/03/24 15:18:30 INFO namenode.HostFileManager: read excludes:
HostSet(
)
14/03/24 15:18:30 INFO blockmanagement.DatanodeManager: dfs.block.invalidate.limit=1000
14/03/24 15:18:30 INFO util.GSet: Computing capacity for map BlocksMap
14/03/24 15:18:30 INFO util.GSet: VM type       = 32-bit
14/03/24 15:18:30 INFO util.GSet: 2.0% max memory = 966.7 MB
14/03/24 15:18:30 INFO util.GSet: capacity      = 2^22 = 4194304 entries
14/03/24 15:18:30 INFO blockmanagement.BlockManager: dfs.block.access.token.enable=false
14/03/24 15:18:30 INFO blockmanagement.BlockManager: defaultReplication         = 1
14/03/24 15:18:30 INFO blockmanagement.BlockManager: maxReplication             = 512
14/03/24 15:18:30 INFO blockmanagement.BlockManager: minReplication             = 1
14/03/24 15:18:30 INFO blockmanagement.BlockManager: maxReplicationStreams      = 2
14/03/24 15:18:30 INFO blockmanagement.BlockManager: shouldCheckForEnoughRacks  = false
14/03/24 15:18:30 INFO blockmanagement.BlockManager: replicationRecheckInterval = 3000
14/03/24 15:18:30 INFO blockmanagement.BlockManager: encryptDataTransfer        = false
14/03/24 15:18:30 INFO namenode.FSNamesystem: fsOwner             = root (auth:SIMPLE)
14/03/24 15:18:30 INFO namenode.FSNamesystem: supergroup          = supergroup
14/03/24 15:18:30 INFO namenode.FSNamesystem: isPermissionEnabled = true
14/03/24 15:18:30 INFO namenode.FSNamesystem: HA Enabled: false
14/03/24 15:18:30 INFO namenode.FSNamesystem: Append Enabled: true
14/03/24 15:18:30 INFO util.GSet: Computing capacity for map INodeMap
14/03/24 15:18:30 INFO util.GSet: VM type       = 32-bit
14/03/24 15:18:30 INFO util.GSet: 1.0% max memory = 966.7 MB
14/03/24 15:18:30 INFO util.GSet: capacity      = 2^21 = 2097152 entries
14/03/24 15:18:30 INFO namenode.NameNode: Caching file names occuring more than 10 times
14/03/24 15:18:30 INFO namenode.FSNamesystem: dfs.namenode.safemode.threshold-pct = 0.9990000128746033
14/03/24 15:18:30 INFO namenode.FSNamesystem: dfs.namenode.safemode.min.datanodes = 0
14/03/24 15:18:30 INFO namenode.FSNamesystem: dfs.namenode.safemode.extension     = 30000
14/03/24 15:18:30 INFO namenode.FSNamesystem: Retry cache on namenode is enabled
14/03/24 15:18:30 INFO namenode.FSNamesystem: Retry cache will use 0.03 of total heap and retry cache entry expiry time is 600000 millis
14/03/24 15:18:30 INFO util.GSet: Computing capacity for map Namenode Retry Cache
14/03/24 15:18:30 INFO util.GSet: VM type       = 32-bit
14/03/24 15:18:30 INFO util.GSet: 0.029999999329447746% max memory = 966.7 MB
14/03/24 15:18:30 INFO util.GSet: capacity      = 2^16 = 65536 entries
14/03/24 15:18:30 INFO common.Storage: Storage directory /dfs/name has been successfully formatted.
14/03/24 15:18:30 INFO namenode.FSImage: Saving image file /dfs/name/current/fsimage.ckpt_0000000000000000000 using no compression
14/03/24 15:18:30 INFO namenode.FSImage: Image file /dfs/name/current/fsimage.ckpt_0000000000000000000 of size 196 bytes saved in 0 seconds.
14/03/24 15:18:30 INFO namenode.NNStorageRetentionManager: Going to retain 1 images with txid >= 0
14/03/24 15:18:30 INFO util.ExitUtil: Exiting with status 0
14/03/24 15:18:30 INFO namenode.NameNode: SHUTDOWN_MSG: 
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at hadoop/192.168.47.74
************************************************************/
hadoop 2.2.0可以使用start-all.sh来吧所有的进程开启
在浏览器中输入http://localhost:8088登入hadoop管理界面

在换一个端口50070，查看节点信息


部署完成，这里我们就是实现了伪分布式单机hadoop的开发环境。后续发力会出hadoop 分布式文件系统，感受一下google的文件系统，其实和linux的
GFS差不多。。