Nagios → A DevOps tool (part -1)

Why we need Nagios →

Basically It is monitering tool and why we need it →

1. If any failure inside CI/CD pipeline
2. Failure inside the aplication
3. Infrastructure failure
4. or if your code getting fail due to some error and other things

Why we used nagios →

1. To avoid downtown of application
2. Nagios is an open source means it is free for everyone.
3. It is based on client server architecture.
4. In case of any failure it gives an alert to technical team.
5. It uses port number 5666 and 5667 and 5668 to monitor its client.
6. Detect all types of network or server issues
7. allow you to monitor and troubleshoot server performance issues.
8. Sometimes it automatically fix problem.

Phases Of continous Monitering →

1. Define → first you define your monitering Strategy
2. Establish → How frequently you are going to moniter it
3. Implement
4. Analyze data and report finding
5. Respond
6. Renew and Update

Nagios Architecture →

It is a client Server architecture. Usually on a network and a nagios server is running on a host and plugins are running on all the remote host which should you monitor.

In this image you see a nagios server in central and all the host is checked by ping command

How Nagios works →

1. Mention all the details in configuration file.
2. Daemon read those details what data to be collected.
3. Daemon use and NRPE plugin to collect data from nodes and store in its own database.
4. Finally shown in dashboard.

Features of Nagios →

1. Good lag and database system
   2.informative and attractive web interface
   3. automatically sends alert , if condition changes(warning,normal — ->critical)
   4. help you to detect network errors or server crashes
   5. you can monitor the entire business process and its Infra with a single pass
   6. monitor network services like http, smtp, ftp ,ssh, pop, DNS, ldap, ipmi, etc…..