Use these steps to validate your installation.
Start the Nagios server and httpd.
/etc/init.d/nagios start /etc/init.d/httpd start
Confirm the server is running.
/etc/init.d/nagios status
This should return:
nagios (pid #) is running...
Run the following command:
/usr/lib64/nagios/plugins/check_hdfs_capacity.php -h namenode_hostname -p 50070 -w 80% -c 90%
This should return:
OK: DFSUsedGB:<some#>, DFSTotalGB:<some#>
Browse to the Nagios server:
http://<nagios.server>/nagios
Login using the Nagios admin username (nagiosadmin) and password (see Set the Nagios Admin Password).
Click on hosts to validate that all the hosts in the cluster are listed.
Click on services to validate all the Hadoop services are listed for each host.
Login to one of your cluster DataNodes.
Stop the TaskTracker service.
su -l mapred -c "/usr/lib/hadoop/bin/hadoop-daemon.sh --config /etc/hadoop/conf stop tasktracker"
Validate that you received an alert at the admin email address and that you have critical state showing on the console.
Start the TaskTracker service.
su -l mapred -c "/usr/lib/hadoop/bin/hadoop-daemon.sh --config /etc/hadoop/conf start tasktracker"
Validate that you received an alert at the admin email address and that critical state is cleared on the console.
