Working with Nagios

Nagios is a system monitoring and alerting tool. This section will focus on configuring a simple Nagios installation that monitors the nodes in our Elasticsearch cluster, as well as the Elasticsearch process on those. If a node or process shuts down, Nagios will send us an alert.

It's a good idea to install Nagios on a host outside of the Elasticsearch clusters in order to avoid affecting the monitoring process due to other things going on in the system, such as high Elasticsearch load. Create a new host for Nagios and call it elasticsearc h-nagios-01.

Installing Nagios

In addition to the dedicated Nagios host, elasticsearch-nagios-01, install the Nagios Remote Plugin Executor (NRPE) server on all of the Elasticsearch cluster nodes in order to monitor the Elasticsearch process. Follow these steps:

1. Run the following command on each of the Elasticsearch nodes: elasticsearch-node-01, elasticsearch-node-02, elasticsearch-node-03, and elasticsea rch-marvel-01:

   sudo apt-get install...