正文之前
作為一個以后肯定要做大數據的人，至今還沒玩過Java 和 Hadoop 會不會被老師打死？所以就想著，在我的國外的云主機上搭建個Hadoop ，以后在 dell 電腦的ubuntu系統下也搭建一個，然后還有一臺老戴爾可以搭一個，mac也可以搭一個，勉強算是一個分布式集群了？不管了。反正今天先把Hadoop在Ubuntu 17.04 下搭建好吧！
正文
國內的資料都太老了。我就用Google搜了一波，果然好用啊！！
之后選擇了一個教程：
http://www.admintome.com/blog/installing-hadoop-on-ubuntu-17-10/
下面進入安裝環節：
1、 Install required software
# apt update && apt upgrade -y
# reboot
# apt install -y openjdk-8-jdk
# apt install ssh pdsh -y
2、 Download Hadoop
# wget http://apache.cs.utah.edu/hadoop/common/stable/hadoop-2.8.2.tar.gz
# tar -xzvf hadoop-2.8.2.tar.gz
# cd hadoop-2.8.2/
上面的網址現在好像廢了。我找了一些新的，你們自己看條件選擇：
http://apache.claz.org/hadoop/common/hadoop-2.8.2/hadoop-2.8.2.tar.gz
http://apache.claz.org/hadoop/common/
下面是下載安裝和安裝完畢之后的樣子:
下面進入配置環節：
We need to make some additions to our configuration, so edit the next couple of files with the appropriate contents:
etc/hadoop/hadoop-env.sh
export JAVA_HOME=/usr
etc/hadoop/core-site.xml
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://localhost:9000</value>
</property>
</configuration>
etc/hadoop/hdfs-site.xml
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
Now in order to make the scripts work, we need to setup passwordless SSH to localhost:
$ ssh-keygen -t rsa -P '' -f ~/.ssh/id_rsa
$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
$ chmod 0600 ~/.ssh/authorized_keys
Format the HDFS filesystem.
# bin/hdfs namenode -format
And finally, start up HDFS.
# sbin/start-dfs.sh
After it starts up you can access the web interface for the NameNode at this URL:
http://{server-ip}50070 .
因為我的是云主機，所以直接用類似網站的方式也可以進入：
Configure YARN
Create the directories we will need for YARN.
# bin/hdfs dfs -mkdir /user
# bin/hdfs dfs -mkdir /user/root
Edit etc/hadoop/mapred-site.xml and add the following contents:
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
</configuration>
And edit
etc/hadoop/yarn-site.xml:
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.nodemanager.vmem-check-enabled</name>
<value>false</value>
</property>
Start YARN:
# sbin/start-yarn.sh
如果無法啟動，報錯如下：
root@HustWolfzzb:/home/hustwolf/Hadoop/hadoop-2.8.2# sbin/start-yarn.sh
starting yarn daemons
resourcemanager running as process 16803. Stop it first.
localhost: starting nodemanager, logging to /home/hustwolf/Hadoop/hadoop-2.8.2/logs/yarn-root-nodemanager-HustWolfzzb.out
root@HustWolfzzb:/home/hustwolf/Hadoop/hadoop-2.8.2# kill -9 16803
root@HustWolfzzb:/home/hustwolf/Hadoop/hadoop-2.8.2# sbin/start-yarn.sh
starting yarn daemons
starting resourcemanager, logging to /home/hustwolf/Hadoop/hadoop-2.8.2/logs/yarn-root-resourcemanager-HustWolfzzb.out
localhost: nodemanager running as process 17374. Stop it first.
root@HustWolfzzb:/home/hustwolf/Hadoop/hadoop-2.8.2# ls
那么，先把所有的先關了。方法是到sbin下采用stop腳本，可以直接stop-all.sh 也可以試試stop-dfs.sh stop-yarn.sh 兩個搭配。然后再開啟一次就ok.
You can now view the web interface at
Testing our installation
In order to test that everything is working we can run a MapReduce job using YARN:
# bin/yarn jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.8.2.jar pi 16 1000
This is going to calculate PI to 16 decimal places for us using the quasiMonteCarlo method. After a minute or two you should get your response:
Job Finished in 96.095 seconds
Estimated value of Pi is 3.14250000000000000000
我在這兒遇到了一個很苦惱的問題就是:
Number of Maps = 16
Samples per Map = 1000
17/11/24 07:49:52 WARN ipc.Client: Failed to connect to server: localhost/127.0.0.1:9000: try once and fail.
java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:495)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:682)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:778)
at org.apache.hadoop.ipc.Client$Connection.access$3500(Client.java:410)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1544)
at org.apache.hadoop.ipc.Client.call(Client.java:1375)
at org.apache.hadoop.ipc.Client.call(Client.java:1339)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:227)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:116)
at com.sun.proxy.$Proxy10.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:792)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:409)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:163)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:155)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:346)
at com.sun.proxy.$Proxy11.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1704)
at org.apache.hadoop.hdfs.DistributedFileSystem$27.doCall(DistributedFileSystem.java:1436)
at org.apache.hadoop.hdfs.DistributedFileSystem$27.doCall(DistributedFileSystem.java:1433)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1433)
at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1437)
at org.apache.hadoop.examples.QuasiMonteCarlo.estimatePi(QuasiMonteCarlo.java:278)
at org.apache.hadoop.examples.QuasiMonteCarlo.run(QuasiMonteCarlo.java:358)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:76)
at org.apache.hadoop.examples.QuasiMonteCarlo.main(QuasiMonteCarlo.java:367)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:71)
at org.apache.hadoop.util.ProgramDriver.run(ProgramDriver.java:144)
at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:74)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.RunJar.run(RunJar.java:234)
at org.apache.hadoop.util.RunJar.main(RunJar.java:148)
java.net.ConnectException: Call From HustWolfzzb/127.0.1.1 to localhost:9000 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:801)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:732)
at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1487)
at org.apache.hadoop.ipc.Client.call(Client.java:1429)
at org.apache.hadoop.ipc.Client.call(Client.java:1339)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:227)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:116)
at com.sun.proxy.$Proxy10.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:792)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:409)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:163)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:155)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:346)
at com.sun.proxy.$Proxy11.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1704)
at org.apache.hadoop.hdfs.DistributedFileSystem$27.doCall(DistributedFileSystem.java:1436)
at org.apache.hadoop.hdfs.DistributedFileSystem$27.doCall(DistributedFileSystem.java:1433)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1433)
at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1437)
at org.apache.hadoop.examples.QuasiMonteCarlo.estimatePi(QuasiMonteCarlo.java:278)
at org.apache.hadoop.examples.QuasiMonteCarlo.run(QuasiMonteCarlo.java:358)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:76)
at org.apache.hadoop.examples.QuasiMonteCarlo.main(QuasiMonteCarlo.java:367)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:71)
at org.apache.hadoop.util.ProgramDriver.run(ProgramDriver.java:144)
at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:74)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.RunJar.run(RunJar.java:234)
at org.apache.hadoop.util.RunJar.main(RunJar.java:148)
Caused by: java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:495)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:682)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:778)
at org.apache.hadoop.ipc.Client$Connection.access$3500(Client.java:410)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1544)
at org.apache.hadoop.ipc.Client.call(Client.java:1375)
... 38 more
至今還沒解決，不過文章實在沒啥好改的了。后續如果有了解決之道，我就在評論區貼出來，或者直接修改文章吧！拜了個拜~ 健身去~~！！
This should be enough to get you started on your Hadoop journey. Subscribe to my newsletter below to get notifications of more Hadoop articles.
I hope you enjoyed this post. If it was helpful or if it was way off then please comment and let me know.
好像成功了？？？我好像是漏了建立hdfs用戶的那一關？然后還有就是重啟了一次，以及對于一些東西的缺漏。 不過就在我期待值最高的時候，事實給了我狠狠的一擊。好吧，GG。不過還是發現了不少了的有用的教程！！
正文之后
人家老外英文寫的挺好的，我就不多改了。想必就算看不大懂也可以摸索著在百度翻譯的幫助下get 到點，實在不行可以發評論問我嘛 而且，命令都給你整好了，難道還不會？不存在的！！
