Nagios is an open source network monitoring system designed to monitor all aspects of your Hadoop cluster (such as hosts, services, and so forth) over the network. It can monitor many facets of your installation, ranging from operating system attributes like CPU and memory usage to the status of applications, files, and more. Nagios provides a flexible, customizable framework for collecting data on the state of your Hadoop cluster.
Nagios is primarily used for the following kinds of tasks:
Getting instant information about your organization's Hadoop infrastructure
Detecting and repairing problems, and mitigating future issues, before they affect end-users and customers
Leveraging Nagios’ event monitoring capabilities to receive alerts for potential problem areas
Analyzing specific trends; for example: what is the CPU usage for a particular Hadoop service weekdays between 2 p.m. and 5 p.m
