In DevOps culture, there will be a requirement to use and work on multiple tools and infrastructure requirements. In the DevOps cycle, there are various phases starts from planning to deployment and includes coding, monitoring.
Let us take the monitoring concept here, in general monitoring is like monitoring something which is critically required to us or someone. In DevOps, control is a continuous activity of monitoring server or application in the aspects of downtime and frequent failures. Why can’t I use a tool for this activity? To avoid my time on monitoring as this can be a possible solution. Here it comes Nagios.
Nagios is a continuous monitoring and open source to monitor infrastructure services like server, applications, network devices like switches. In infrastructure, we may contain various servers and multiple applications running on top of it. So, securing the forms is a major for every organization but finding the alert before some unsecured program runs is also a smart and essential task. I think Nagios plays a significant role here. Nagios can check the status of the device with agents or with native protocols. Nagios planned and designed to work on a Linux environment, and we can monitor Linux, windows, Unix base devices using Nagios.
Nagios has a simple architecture for its well-defined execution, and it helps Nagios to become a leader in the market. Nagios is a server-client architecture. Nagios server is a machine where its core activities will run, and the Nagios server uses plugin concept to communicate with the remote servers or devices. Nagios server contains some background services that will run continuously and to fulfil our exact requirement that is called Nagios daemon. This daemon enables the exchange of information between the Nagios system and subsystem.
As I mentioned above, Nagios supports Agent and agent-less working mechanism. Let’s see how it works. Nagios agent is a program that runs in client machine to exchange information to the server. It will help the server to import data from the client machines easily. While coming to agent-less, it uses a default or native protocols which client machines are having and running like messaging protocols.
Nagios main aim is to focus on a few mandatory things for infrastructure automation, so using Nagios what we can do more? Using Nagios, we can monitor remote machine memory, and disk usages, CPU loads and processes which are currently running, in next level of monitoring of Nagios will cover services and protocols. Using Nagios, we can monitor network services like SMTP, HTTP, SNMP, SSH, FTP, POP and other standard networking protocols. Monitoring is in two ways; one is using the terminal or CLI based and other is GUI (web-based using CGI component in Nagios server).
Nagios send alerts to the team who are working on it like via emails or SMS based on the interest of groups. Simple it will send alerts like a warning, Down, up.
Nagios has two projects, mainly.
1. Nagios core – Free
It is freely available to monitor infrastructure servers and network devices.
2. Nagios XI – Enterprise solution
It is an extension for Nagios core and equipped with advanced features compared to the Nagios core.
- Continuous monitoring of servers and problem detection
- It is useful to reduce downtime to run the business smoothly
- It will send alerts immediately if server down or up.
- It is very accurate in handling the service status like stopped or running.
- Easily manageable and secured
My experience: I used Nagios core to monitor 200 servers with multiple application on top of it. It is effortless to manage applications and servers with less downtime. It will be add on if we configure SMS alerts also or we can run it with email too.