HADOOP之3节点集群

1.apache提供的hadoop-2.4.1的安装包是在32位操作系统编译的，因为hadoop一些C++的本地库，所以如果在64位的操作上安装hadoop-2.4.1就需要重新在64操作系统上重新编译

2.本次搭建使用了2.7.1，hadoop2.7.1是稳定版。

      3.节点包括了namenode的高可用，jobtracker的高可用，zookeeper高可用集群（后期更新）

      4、3个节点的配置完全相同，只要在master配置完成后SCP到其他2节点上即可

链接：http://pan.baidu.com/s/1i4LCmAp 密码：302x hadoop+hive下载

架构图：

##三个节点的/etc/hosts一致

• 添加ssh 之间的互信：ssh-keygen -t rsa

###若是原来存在的建议删除重新设置一次

# cd

#cd .ssh

#rm –rf .usr/bin/

测试jdk是否OK

java -version

java version "1.7.0_09-icedtea"

OpenJDK Runtime Environment(rhel-2.3.4.1.el6_3-x86_64)

OpenJDK 64-Bit Server VM (build 23.2-b09,mixed mode)

若提示：/usr/bin/java: /lib/ld-linux.so.2: bad ELF interpreter:

安装yum install glibc.i686 再次执行没问题

• 配置、添加用户hadoop

# useradd hadoop

#配置之前，先在本地文件系统创建以下文件夹：

/home/hadoop/tmp、/home/dfs/data、/home/dfs/name，3个节点一样

Mkdir /home/hadoop/tmp

mkdir /home/hadoop/dfs/data -p

mkdir /home/hadoop/dfs/name -p

#hadoop的配置文件在程序目录下的etc/hadoop，主要涉及的配置文件有7个：都在/hadoop/etc/hadoop文件夹下

/usr/local/hadoop/etc/hadoop/hadoop-env.sh #记录hadoop要用的环境变量
/usr/local/hadoop /etc/hadoop/yarn-env.sh#记录YARN要用的环境变量
/usr/local/hadoop /etc/hadoop/slaves#运行DN和NM的机器列表（每行一个）
/usr/local/hadoop/etc/hadoop/core-site.xml#hadoopCORE的配置，如HDFS和MAPREDUCE常用的I/O设置
/usr/local/hadoop/etc/hadoop/hdfs-site.xml#hdfs守护进程的配置，包括NN和SNN DN
/usr/local/hadoop/etc/hadoop/mapred-site.xml#mapreduce计算框架的配置
/usr/local/hadoop/etc/hadoop/yarn-site.xml#YARN守护进程的配置，报错RM和NM等

1、  修改hadoop-env.sh,设置jdk路径,在第25行中修改：

export JAVA_HOME=/usr/local/jdk

2、  修改core-site.xml

fs.default.name是NameNode的URI。hdfs://主机名:端口/hadoop.tmp.dir：Hadoop的默认临时路径，这个最好配置，如果在新增节点或者其他情况下莫名其妙的DataNode启动不了，就删除此文件中的tmp目录即可。不过如果删除了NameNode机器的此目录，那么就需要重新执行NameNode格式化的命令。

<configuration>

<property>

    <name>fs.defaultFS</name>

   <value>hdfs://haproxy:9000</value>

</property>

<property>

   <name>io.file.buffer.size</name>

    <value>131072</value>

</property>

<property>

    <name>hadoop.tmp.dir</name>

    <value>file:/home/hadoop/tmp</value>

    <description>abase for othertemporary directories</description>

</property>

<property>

   <name>hadoop.proxyuser.spark.hosts</name>

    <value>*</value>

</property>

<property>

   <name>hadoop.proxyuser.spark.groups</name>

    <value>*</value>

</property>

3、配置  hdfs-site.xml 文件-->>增加hdfs配置信息（namenode、datanode端口和目录位置）

dfs.name.dir是NameNode持久存储名字空间及事务日志的本地文件系统路径。当这个值是一个逗号分割的目录列表时，nametable数据将会被复制到所有目录中做冗余备份。
dfs.data.dir是DataNode存放块数据的本地文件系统路径，逗号分割的列表。当这个值是逗号分割的目录列表时，数据将被存储在所有目录下，通常分布在不同设备上。
dfs.replication是数据需要备份的数量，默认是3，如果此数大于集群的机器数会出错。
注意：此处的name1、name2、data1、data2目录不能预先创建，hadoop格式化时会自动创建，如果预先创建反而会有问题。

<configuration>

<property>

    <name> dfs.namenode.name.dir </name>

   <value>/home/hadoop/dfs/name/name1</value>

    <final>true</final>

</property>   

<property>

    <name>dfs.datanode.data.dir</name>

   <value>/home/hadoop/dfs/data/data1</value>

    <final>true</final>

</property>

<property>

    <name>dfs.replication</name>

    <value>2</value>

    <final>true</final>

</property>

</configuration>

4、mapred-site.xml文件

<configuration>

<property>

   <name>mapreduce.framework.name</name>

    <value>yarn</value>

</property>

<property>

   <name>mapreduce.jobhistory.address</name>

    <value>haproxy:10020</value>

</property>

<property>

   <name>mapreduce.jobhistory.webapp.address</name>

    <value>haproxy:19888</value>

</property>

</configuration>

4、修改yarn-site.xml

<configuration>

<property>

   <name>yarn.nodemanager.aux-services</name>

   <value>mapreduce_shuffle</value>

</property>

<property>

   <name>yarn.nodemanager.aux-services.mapreduce.shufle.class</name>

   <value>org.apache.hadoop.mapred.ShuffleHandler</value>

</property>

<property>

   <name>yarn.resourcemanager.address</name>

    <value>haproxy:8032</value>

</property>

<property>

   <name>yarn.resourcemanager.scheduler.address</name>

    <value>haproxy:8030</value>

</property>

<property>

   <name>yarn.resourcemanager.resource-tracker.address</name>

    <value>haproxy:8035</value>

</property>

<property>

    <name>yarn.resourcemanager.admin.address</name>

    <value>haproxy:8033</value>

</property>

<property>

   <name>yarn.resourcemanager.webapp.address</name>

    <value>haproxy:8088</value>

</property>

5、配置masters和slaves主从结点

6、格式文件系统

这一步在主结点master上进行操作

报错

./hdfs: /usr/local/jdk/bin/java: /lib/ld-linux.so.2: bad ELFinterpreter: No such file or directory

yum install glibc.i686

#cd /usr/local/hadoop/bin/

./hdfs namenode -format

SHUTDOWN_MSG: Shutting down NameNode athaproxy/192.168.1.107

7、启动主节点

#/usr/local/hadoop/sbin/start-dfs.sh

问题1：

启动的时候日志有：

It's highly recommended that you fix the library with'execstack -c <libfile>', or link it with '-z noexecstack'.

经过修改主要是环境变量设置问题：

#vi /etc/profile或者vi~/.bash_profile

export HADOOP_HOME=/usr/local/hadoop

exportHADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native

exportHADOOP_OPTS="-Djava.library.path=$HADOOP_HOME/lib"

问题2：

WARN util.NativeCodeLoader: Unable toload native-hadoop library for your platform... using builtin-java classeswhere applicable

测试发现：

/usr/local/hadoop/bin/hadoop fs -ls /

16/11/16 16:16:42 WARN util.NativeCodeLoader: Unable to loadnative-hadoop library for your platform... using builtin-java classes whereapplicable

ls: Call From haproxy/192.168.1.107 to haproxy:9000 failed onconnection exception: java.net.ConnectException: Connection refused; For moredetails see:  http://wiki.apache.org/hadoop/ConnectionRefused

增加调试信息设置

$ export HADOOP_ROOT_LOGGER=DEBUG,console

启动日志：标志红色的需要按上面的错误提示做相应的处理

16/11/19 15:45:27 WARNutil.NativeCodeLoader: Unable to load native-hadoop library for yourplatform... using builtin-java classes where applicable

Starting namenodes on [mycat]

The authenticity of host 'mycat(127.0.0.1)' can't be established.

RSA key fingerprint is3f:44:d6:f4:31:b0:5b:ff:86:b2:5d:87:f2:d9:b8:9d.

Are you sure you want to continueconnecting (yes/no)? yes

mycat: Warning: Permanently added'mycat' (RSA) to the list of known hosts.

mycat: starting namenode, logging to/usr/local/hadoop/logs/hadoop-root-namenode-mycat.out

mycat: Java HotSpot(TM) Client VMwarning: You have loaded library /usr/local/hadoop/lib/native/libhadoop.so.1.0.0which might have disabled stack guard. The VM will try to fix the stack guardnow.

mycat: It's highly recommended that you fix the library with'execstack -c <libfile>', or link it with '-z noexecstack'.

haproxy: starting datanode, logging to/usr/local/hadoop/logs/hadoop-root-datanode-haproxy.out

haproxy_slave: starting datanode,logging to /usr/local/hadoop/logs/hadoop-root-datanode-haproxy_slave.out

haproxy: /usr/local/hadoop/bin/hdfs: line 304:/usr/local/jdk/bin/java: No such file or directory

haproxy: /usr/local/hadoop/bin/hdfs: line 304: exec:/usr/local/jdk/bin/java: cannot execute: No such file or directory

haproxy_slave: /usr/local/hadoop/bin/hdfs:/usr/local/jdk/bin/java: /lib/ld-linux.so.2: bad ELF interpreter: No such fileor directory

haproxy_slave:/usr/local/hadoop/bin/hdfs: line 304: /usr/local/jdk/bin/java: Success

Starting secondary namenodes [0.0.0.0]

The authenticity of host '0.0.0.0(0.0.0.0)' can't be established.

RSA key fingerprint is3f:44:d6:f4:31:b0:5b:ff:86:b2:5d:87:f2:d9:b8:9d.

Are you sure you want to continueconnecting (yes/no)? yes

0.0.0.0: Warning: Permanently added'0.0.0.0' (RSA) to the list of known hosts.

0.0.0.0: starting secondarynamenode,logging to /usr/local/hadoop/logs/hadoop-root-secondarynamenode-mycat.out

0.0.0.0: Java HotSpot(TM) Client VMwarning: You have loaded library/usr/local/hadoop/lib/native/libhadoop.so.1.0.0 which might have disabled stackguard. The VM will try to fix the stack guard now.

0.0.0.0: It's highly recommended thatyou fix the library with 'execstack -c <libfile>', or link it with '-znoexecstack'.

16/11/19 15:46:01 WARNutil.NativeCodeLoader: Unable to load native-hadoop library for yourplatform... usi

问题3：若在datanode看不到节点的信息

若看不到2个SLAVE信息，有可能是配置文件问题

1、看看/usr/local/hadoop/logs下的日志

2、检查/usr/local/hadoop/etc/hadoop/hdfs-site.xml的配置信息

3、检查下/etc/hosts的配置，测试的时候，勿把127.0.0.1和hostname绑定一起导致问题，借鉴

问题的处理方法：

       (1)停掉集群服务

　　(2)在出问题的datanode节点上删除data目录，data目录即是在hdfs-site.xml文件中配置的dfs.data.dir目录，本机器上那个是/var/lib/hadoop-0.20/cache/hdfs/dfs/data/ (注：我们当时在所有的datanode和namenode节点上均执行了该步骤。以防删掉后不成功，可以先把data目录保存一个副本).

      (3)格式化namenode.

　　(4)重新启动集群。

##到此3主备集群OK