Hey all, OK thanks for your advice on setting up a hadoop test environment to get started in learning how to use hadoop! I'm very excited to be able to start to take this plunge!
Although rather than using BigTop or Cloudera, I just decided to go for a straight apache hadoop install. I setup 3 t2micro instances on EC2 for my training purposes. And that seemed to go alright! As far as installing hadoop and starting the services goes. I went so far as to setup the ssh access that the nodes will need. And the services seem to start without issue: bash-4.2$ whoami hadoop bash-4.2$ start-dfs.sh Starting namenodes on [hadoop1.mydomain.com] hadoop1.mydomain.com: starting namenode, logging to /home/hadoop/logs/hadoop-hadoop-namenode-hadoop1.out hadoop2.mydomain.com: starting datanode, logging to /home/hadoop/logs/hadoop-hadoop-datanode-hadoop2.out hadoop3.mydomain.com: starting datanode, logging to /home/hadoop/logs/hadoop-hadoop-datanode-hadoop3.out Starting secondary namenodes [0.0.0.0] 0.0.0.0: starting secondarynamenode, logging to /home/hadoop/logs/hadoop-hadoop-secondarynamenode-hadoop1.out bash-4.2$ start-yarn.sh starting yarn daemons starting resourcemanager, logging to /home/hadoop/logs/yarn-hadoop-resourcemanager-hadoop1.out hadoop2.mydomain.com: starting nodemanager, logging to /home/hadoop/logs/yarn-hadoop-nodemanager-hadoop2.out hadoop3.mydomain.com: starting nodemanager, logging to /home/hadoop/logs/yarn-hadoop-nodemanager-hadoop3.out And I opened up these ports on the security groups for the two data nodes: [root@hadoop2:~] #netstat -tulpn | grep -i listen | grep java tcp 0 0 0.0.0.0:*50010* 0.0.0.0:* LISTEN 21405/java tcp 0 0 0.0.0.0:*50075* 0.0.0.0:* LISTEN 21405/java tcp 0 0 0.0.0.0:*50020* 0.0.0.0:* LISTEN 21405/java But when I go to the hadoop web interface at: http://hadoop1.mydomain.com:50070 <http://hadoop1.jokefire.com:50070/> And click on the data node tab, I see no nodes are connected! I see that the hosts are listening on all interfaces. I also put all hosts into the /etc/hosts file on the master node. Using the first data node as an example I can telnet into each port on both datanodes from the master node: bash-4.2$ telnet hadoop2.mydomain.com *50010* Trying 172.31.63.42... Connected to hadoop2.mydomain.com. Escape character is '^]'. ^] telnet> quit Connection closed. bash-4.2$ telnet hadoop2.mydomain.com *50075* Trying 172.31.63.42... Connected to hadoop2.mydomain.com. Escape character is '^]'. ^] telnet> quit Connection closed. bash-4.2$ telnet hadoop2.mydomain.com *50020* Trying 172.31.63.42... Connected to hadoop2.mydomain.com. Escape character is '^]'. ^] telnet> quit Connection closed. So apparently I've hit my first snag in setting up a hadoop cluster. Can anyone give me some tips as to how I can get the data nodes to show as connected to the master? Thanks Tim -- GPG me!! gpg --keyserver pool.sks-keyservers.net --recv-keys F186197B
