General Troubleshooting
Ambari Server: Check /var/log/ambari-server/ambari-server.[log|out] for errors.
Ambari Agent: Check /var/log/ambari-agent/ambari-agent.[log|out] for errors.
Services fail to start up
- HDFS: Check log files under /var/log/hadoop/hdfs
- MapReduce: Check log files under /var/log/hadoop/mapred
Nagios alerts don't show up in Ambari Web
- Run "service httpd restart"
Installing a new cluster on top of an existing cluster
When installing a Hadoop cluster via Ambari on hosts that already have Hadoop bits installed (including an existing cluster deployed via Ambari), perform the following:
- Stop all the services on all the nodes(including ganglia and nagios)
- It is also a good practice to delete the rpms from all nodes.
search for the rpms:
rpm -qa | grep ganglia
rpm -qa | grep oozie
rpm -qa | grep sqoop
rpm -qa | grep pig
rpm -qa | grep nagios
rpm -qa | grep hadoop
and remove them :
rpm -e <package name>