Chapter 25. Installing Nagios (Deprecated)

Create the following Nagios directories:

mkdir /var/nagios /var/nagios/rw /var/log/nagios /var/log/nagios/spool/checkresults /var/run/nagios

Change ownership on those directories to the Nagios user:

chown -R nagios:nagios /var/nagios /var/nagios/rw /var/log/nagios /var/log/nagios/spool/checkresults /var/run/nagios

Copy the contents of the objects folder into place:

cp <tmp-directory>/nagios/objects/*.* /etc/nagios/objects/

Copy the contents of the plugins folder into place:

cp <tmp-directory>/nagios/plugins/*.* /usr/lib64/nagios/plugins/

Choose a Nagios administrator password, for example, “admin”.

Set the password. Use the following command:

htpasswd -c -b /etc/nagios/htpasswd.users nagiosadmin admin

Open /etc/nagios/objects/contacts.cfg with a text editor.

Change the nagios@localhost value to the admin email address so it can receive alerts.

Open /etc/nagios/nagios.cfg with a text editor.

In the section OBJECT CONFIGURATION FILE(S), add the following:

# Definitions for hadoop servers 
cfg_file=/etc/nagios/objects/hadoop-commands.cfg 
cfg_file=/etc/nagios/objects/hadoop-hosts.cfg 
cfg_file=/etc/nagios/objects/hadoop-hostgroups.cfg 
cfg_file=/etc/nagios/objects/hadoop-services.cfg 
cfg_file=/etc/nagios/objects/hadoop-servicegroups.cfg

Change the command-file directive to /var/nagios/rw/nagios.cmd:

command_file=/var/nagios/rw/nagios.cmd

Open /etc/nagios/objects/hadoop-hosts.cfg with a text editor.

Create a "define host { … }" entry for each host in your cluster using the following format:

define host {
 alias @HOST@ 
 host_name @HOST@ 
 use linux-server 
 address @HOST@ 
 check_interval 0.25
 retry_interval 0.25
 max_check_attempts 4
 notifications_enabled 1
 first_notification_delay 0 # Send notification soon after
 #change in the hard state 
 notification_interval 0 # Send the notification once 
 notification_options d,u,r
}

Replace "@HOST@" with the hostname.

Open /etc/nagios/objects/hadoop-hostgroups.cfg with a text editor.

Create host groups based on all the hosts and services you have installed in your cluster. Each host group entry should follow this format:

define hostgroup {
 hostgroup_name@NAME@ 
 alias@ALIAS@
 members@MEMBERS@
}

The parameters (such as @NAME@) are defined in the following table.

The following table lists the core and monitoring host groups:

The following table lists the ecosystem project host groups:

Open /etc/nagios/objects/hadoop-services.cfg with a text editor. This file contains service definitions for the following services: Ganglia, HBase (Master and Region), ZooKeeper, Hive, Templeton, and Oozie.

Remove any service definitions for services you have not installed.

Replace the parameters @NAGIOS_BIN@ and @STATUS_DAT@ based on the operating system.

If you have installed Hive or Oozie services, replace the parameter @JAVA_HOME@ with the path to the Java home. For example, /usr/java/default.

Open /etc/nagios/objects/hadoop-commands.cfg with a text editor.

Replace the @STATUS_DAT@ parameter with the location of the Nagios status file. File location depends on your operating system.

Open /etc/nagios/objects/hadoop-commands.cfg with a text editor.

Add the following commands:

define command{
 command_name check_templeton_status
 command_line $USER1$/check_wrapper.sh $USER1$/check_templeton_status.sh $HOSTADDRESS$ $ARG1$ $ARG2$ $ARG3$ $ARG4$ $ARG5$ $ARG6$ $ARG7$
 }

define command{
 command_name check_tcp_wrapper
 command_line $USER1$/check_wrapper.sh $USER1$/check_tcp -H $HOSTADDRESS$ -p $ARG1$ $ARG2$
 }

Validate the Nagios installation:

nagios -v /etc/nagios/nagios.cfg

Start the Nagios server and httpd:

/etc/init.d/nagios start/etc/init.d/httpd start

Confirm that the Nagios server is running:

/etc/init.d/nagios status

This should return:

nagios (pid #) is running...

To test Nagios Services, 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#>

To test Nagios Access, 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 check that all hosts in the cluster are listed. Click on services to check that all of the Hadoop services are listed for each host.

Test Nagios alerts.