README

Overview 2022-12-24

This is my personal hadoop-3.3.4 docker images based on ubuntu:latest (latest = 22.04 jammy when building this image).

The aim for this image is to provide a base for building a hadoop cluster. After start-up, a ssh deamon will be launched automatically. All the information about the experimental hadoop cluster enverionment, please refer to this hadoop tutorial in Chinese.

Please check the Dockerfile for details.

All the soruce code could be found in github.com/zhaolj/hadoop_docker.

Use as a single node

1. start a single node

   docker run -d -p10122:22 -p19870:9870 --privileged --name hadoop zhaolj/hadoop:latest

2. login via ssh (password: hadoop)

   ssh hadoop@localhost -p10122

3. check ip

   ip addr | grep 172

   

   As example above, the ip is 172.17.0.2.

4. config Go to the hadoop configuration files directory: /opt/hadoop/etc/hadoop.

   cd $HADOOP_HOME/etc/hadoop

   • core-site.xml

     <property>
         <name>fs.defaultFS</name>
         <value>hdfs://<your ip>:9000</value>
     </property>

   • hdfs-site.xml

     <property>
         <name>dfs.replication</name>
         <value>1</value>
     </property>

5. format hdfs

   hdfs namenode -format

6. start HDFS

   start-dfs.sh

7. check processes via jps

8. open the HDFS's HTTP board open the http://localhost:19870/ in your host brower.

Use as a cluster

We are going to build a hadoop cluster with 1 NameNode and 2 DataNodes

We can use another pre-configed images: zhaolj/hadoop-cluster to quick start.

1. create a network for the cluster

   docker network create --subnet=172.20.0.0/16 hnet

2. create the containers (3 nodes)

   docker run -d -p10122:22 -p19870:9870 --name=nn --hostname=nn --network=hnet --ip=172.20.1.1 --add-host=dn1:172.20.1.2 --add-host=dn2:172.20.1.3 --privileged zhaolj/hadoop-cluster:latest
   docker run -d --name=dn1 --hostname=dn1 --network=hnet --ip=172.20.1.2 --add-host=nn:172.20.1.1 --add-host=dn2:172.20.1.3 --privileged zhaolj/hadoop-cluster:latest
   docker run -d --name=dn2 --hostname=dn2 --network=hnet --ip=172.20.1.3 --add-host=nn:172.20.1.1 --add-host=dn1:172.20.1.2 --privileged zhaolj/hadoop-cluster:latest

3. go to the NameNode via ssh (password: hadoop)

   ssh hadoop@localhost -p10122

4. format HDFS

   hdfs namenode -format

5. start HDFS

   start-dfs.sh

   

6. check processes via jps on NameNode

7. check processes via jps on DataNode

   • connect to dn1 via ssh in nn

     ssh dn1
     jps
     exit

     

   • connect to dn2 via ssh in nn

     ssh dn2
     jps
     exit

     

8. open the HDFS's HTTP board open the http://localhost:19870/ in your host brower.

Differences between zhaolj/hadoop and zhaolj/hadoop-cluster

zhaolj/hadoop-cluster includes three pre-configed files for the example cluster network.

1. workers ($HADOOP_HOME/etc/hadoop/workers)

   dn1
   dn2

2. core-site.xml ($HADOOP_HOME/etc/hadoop/core-site.xml)

   add following content in the default configuration (embraced by <configuration>...</configuration>).

   <!-- specify HDFS host & port -->
   <property>
       <name>fs.defaultFS</name>
       <value>hdfs://nn:9000</value>
   </property>
   <!-- specify Hadoop temporary directory -->
   <property>
       <name>hadoop.tmp.dir</name>
       <value>file:///home/hadoop/tmp</value>
   </property>

3. hdfs-site.xml ($HADOOP_HOME/etc/hadoop/hdfs-site.xml)

   add following content in the default configuration (embraced by <configuration>...</configuration>).

   <property>
       <name>dfs.replication</name>
       <value>2</value>
   </property>
   
   <property>
       <name>dfs.namenode.name.dir</name>
       <value>file:///home/hadoop/hdfs/name</value>
   </property>