13 Best Open Source & Free Monitoring Tools In 2023

Monitoring is necessary for businesses to make sure that the required system is up and working. Monitoring various aspects of the IT infrastructure can be quite pesky and cause many difficulties if not done properly.

Regardless of the company’s size, one cannot ignore the need for Server, network, and infrastructure monitoring using the best monitoring tool. All modern cloud and on-premise infrastructure come with the best monitoring solutions.

Also, when it comes to DevOps, monitoring, and observability plays a key role in the team’s performance.

The following are the key areas when it comes to monitoring.

1. Real-time Server Monitoring
2. Network Performance Monitoring
3. Container Monitoring (Docker/Kubernetes/Mesos etc.)
4. Cloud Infrastructure Monitoring (Public & Private)
5. Application monitoring.
6. Cloud-native monitoring.

Professional or Business-grade tech solutions are generally regarded as costly, but that’s not necessarily always the case.

Following is the key list of key indicators for the best monitoring software.

1. Provide indicators on outages and service degradation
2. Detect service outages and unauthorized activities
3. Scalable
4. Able to handle and process huge amounts of monitoring data
5. Collect predefined system/application metrics in real-time
6. Able to provide long-term insights for better capacity planning.
7. Highly available
8. Support all modern cloud, containerized applications, and cloud-native applications.
9. Support metric visualization tools
10. Good traceability 
11. Have a good user-friendly interface.

Numerous absolutely free and open-source network monitoring tools can be considered while looking for monitoring solutions. Let’s take a look at the top-rated open-source monitoring tools and see what works for you!

1. Prometheus

Prometheus is an open-source cloud-native monitoring solution primarily fixated on data gathering and analysis based on time-series data. It enables users to set up monitoring capabilities by utilizing the in-built toolset.

It is an ideal monitoring setup for containerized environments like kubernetes and the best open-source server monitoring tool.

It is able to assemble several metrics on servers, kubernetes, and various devices using SNMP pings and inspect network bandwidth usage from the device point of view, along with the other functions. The PromQL system analyzes data and permits the program to produce plots, tables, and other graphics on the systems it monitors.

The alert manager is another component of Prometheus. It handles alerting for all alerting rules configured in Prometheus.

Prometheus can collect system metrics, application metrics, and metrics from modern containerized applications. Also, it has very good integration with tools like Grafana for visualizing metrics. Grafana is one of the best open-source monitoring dashboards.

2. Zabbix

Zabbix is open-source monitoring software with an easy-to-use interface for users with a low learning curve that provides enterprise-class solutions to large organizations. It is a centralized system that stores the data in a relational DB for efficient processing.

Here is what Zabbix can do.

1. Network Monitoring
2. Server Monitoring
3. Cloud Monitoring
4. Application Monitoring
5. Service Monitoring

3. Nagios

Nagios is an open-source monitoring tool that has been in the market since 1999. It provides numerous facilities like integration with third-party apps using an additional plugin. Considering the length of time that Nagios has been in the industry, there are plenty of plugins written for it.  It can monitor a variety of components including Oss, applications, websites, middleware, web servers, etc.

4. Riemann

Riemann is an ideal open-source monitoring tool for distributed systems. It’s a low-latency even processing system capable of collecting metrics from a variety of distributed systems. It is designed to handle millions of even per second with low latency. It is an apt monitoring tool for highly distributed scalable systems.

5. Sensu

Sensu is endorsed as a full-stack monitoring tool. By means of a single platform, you can monitor services, applications, servers, and reports on business KPIs. Its monitoring does not require a separate workflow.  It supports all the popular Operating Systems like Windows, Linux, etc.

6. Icinga

Icinga is an open-source network monitoring tool that calculates the availability and performance of the network. Through a web interface, your business can observe applications and hosts around your complete network infrastructure. The tool is scalable and easily configurable to function with each type of device. There exist a few Icinga modules for very specific monitoring capabilities, like monitoring for VMWare’s vSphere cloud environment and business process modeling.

7. Cacti

Cacti is an open-source network monitoring tool built on RRD Tool’s data classification and plotting system. The tool utilizes data-gathering functionality and network polling to collect information on various devices on networks of any scope. This comprises the capability to create custom scripts for data gathering along with the facility for SNMP polling. It then showcases this information in easy-to-comprehend plots which can be organized in whichever hierarchy as per your business’s convenience.

8. LibreNMS

LibreNMS is an open-source network monitoring system that utilizes multiple network protocols to observe every device on your network. The LibreNMS API can recover, manage, and plot the data it collects and facilitates horizontal scaling to grow its monitoring abilities along with your network. The tool presents a flexible alerting system that is custom-made to communicate to you by the method that suits best your company. They offer their iOS and Android

9. Observium Community

Observium Community is the free counterpart of Observium’s network monitoring tool. In the free version of the Observium Community, you can monitor a limitless amount of devices along with taking complete advantage of Obersvium’s network mapping attributes. The Observium network monitoring tool features the programmed discovery of connected devices. It also comes well-appointed with discovery protocols to make sure that the map of your network is the latest. In this manner, you can keep track of new devices as they connect with the network.

10. Pandora FMS

Pandora FMS is an open-source monitoring tool that aids businesses to observe their whole IT substructure. It not just features network monitoring capabilities but also Unix and Windows servers and virtual interfaces. For networks, Pandora FMS comprises top-notch features like SNMP support, ICMP polling, network latency monitoring, as well as system overload. Agents can also be installed on devices to observe aspects like device temperature and overheating, as well as for logfile happenings.

11. LogRhythm NetMon Freemium

LogRhythm NetMon Freemium is a free version of LogRhythm NetMon that offers similar business-grade module capturing and analysis abilities as the full version. Though there are restrictions or limits on data processing and module storage, the freemium version still permits the users to perform network risk detection and response functions built on data packet analysis. It also offers a similar network threat alerting system as the full version, letting you stay updated on your network’s performance and security.

12. Famatech Advanced IP Scanner

Famatech’s Advanced IP Scanner is free of cost network monitoring as well as a scanning tool that offers analysis on Local Area Networks and LAN devices. The advanced IP Scanner allows the scanning of devices on the network and remotely regulates the connected computers and other resources. It provides the ability to switch computers off from the tool if the device is not in use and is using resources. The tool connects with Famatech’s Radmin solution for distant IT management, so you can manage the IPs wherever you are.

13. AppNeta PathTest

AppNeta PathTest is a free network volume testing tool intended to aid businesses to comprehend the true ability of their network. PathTest seeks to advance layer three and layer four performance by exhibiting a precise depiction of your network’s maximum capabilities. It deliberately floods your network with data packets to fill the network to its full capacity. Users can set the duration of this test up to a maximum of 10 seconds and run the tests at any time.

Conclusion

Monitoring provides supervisors with a crisp view of the services, applications, and devices running on their network and the ability to track the performance of these resources. This facilitates active management rather than responding to issues as and when they happen.

Open-source monitoring tools are utilized to monitor the status of the framework being used, so as to have warnings of defects, failures, or issues and to improve them. There are monitoring tools for servers, networks, cloud infrastructure, containers, databases, security, execution, site and web use, and applications.

Sometimes, it is wise to use default monitoring systems that come with the infrastructure providers. One example is the AWS cloudwatch. However, open-source monitoring tools provide a lot of functionality to monitor your infrastructure components with a lot of customization.

Opting for an appropriate open-source monitoring solution for your business is not as easy as it seems.

IT professionals like Network and DevOps Engineers need to consider multiple factors while searching for an open-source monitoring solution for their enterprises, such as compatibility, facility, effortlessness, and budget.

As a DevOps engineer myself, I can’t think of a project where we never used monitoring tools. So if you want to become a devops engineer, I would highly suggest you look at open-source monitoring tools.

Also, if you’re looking for the best service discovery tools, read my reviews on the best open-source service discovery tools.