下面给你一个在 Linux(以 CentOS / Ubuntu 为例)部署 Hadoop 的简明实战教程,适合单机 / 伪分布式入门,也说明完全分布式要点。
# Ubuntu
sudo apt update
sudo apt install openjdk-8-jdk -y
# CentOS
sudo yum install java-1.8.0-openjdk-devel -y
验证:
java -version
useradd hadoop
passwd hadoop
su - hadoop
cd /opt
sudo wget https://downloads.apache.org/hadoop/common/hadoop-3.3.6/hadoop-3.3.6.tar.gz
sudo tar -zxvf hadoop-3.3.6.tar.gz
sudo mv hadoop-3.3.6 hadoop
sudo chown -R hadoop:hadoop hadoop
编辑 ~/.bashrc:
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
export HADOOP_HOME=/opt/hadoop
export PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin
生效:
source ~/.bashrc
验证:
hadoop version
vi $HADOOP_HOME/etc/hadoop/core-site.xml
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://localhost:9000</value>
</property>
</configuration>
vi $HADOOP_HOME/etc/hadoop/hdfs-site.xml
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
cp $HADOOP_HOME/etc/hadoop/mapred-site.xml.template $HADOOP_HOME/etc/hadoop/mapred-site.xml
vi $HADOOP_HOME/etc/hadoop/mapred-site.xml
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
</configuration>
vi $HADOOP_HOME/etc/hadoop/yarn-site.xml
<configuration>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
</configuration>
ssh-keygen -t rsa
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys
ssh localhost
hdfs namenode -format
start-dfs.sh
start-yarn.sh
jps
应看到:
hdfs dfs -mkdir /test
hdfs dfs -put ~/.bashrc /test
hdfs dfs -ls /test
workers 文件(旧版 slaves)core-site.xml 指向真实 NameNode IP| 问题 | 解决 |
|---|---|
| JAVA_HOME 报错 | 检查 .bashrc |
| 端口被占用 | 改端口或关防火墙 |
| 权限错误 | 别用 root 跑 Hadoop |
如果你愿意,我可以:
你可以告诉我你的 Linux 版本和使用场景。