How to debug Ambari and Hadoop and Yarn

• Look at ambari agent logs

tail -n 100 /var/log/ambari-agent/ambari-agent.log

• Look at yarn logs

tail -n 100 /var/log/hadoop-yarn/yarn/yarn-yarn-nodemanager-losalamos.bic.cmu.edu.log

• Look at iptables to see if the port is blocked or not. Port Assignment