If your IT team needs a low-cost, lock-in-free cloud monitoring tool, open source might be the way to go.
Cloud computing continues to skyrocket in popularity. But because infrastructure and other cloud services are accessed on-demand and over the internet, they call for a different approach to monitoring than traditional, on-premises models. As a result, IT teams must seek out new tools -- of which there are many.
For the purposes of this piece, we'll focus on open source cloud monitoring tools, the pros and cons, as well as a breakdown of five popular open source options that support the cloud.
Pros and cons of open source cloud monitoring
There are lots of proprietary cloud monitoring tools. Some are built into specific cloud platforms. For example, AWS has Amazon CloudWatch, while Microsoft has Azure Monitor. Others, such as SolarWinds, Splunk and Instana, are third-party offerings that work with any type of cloud environment.
But a proprietary, closed source monitoring tool is not always the best fit. These tools typically cost money, though some are available in free tiers with limited functionality or scalability. Tools that are built into public clouds also pose a lock-in risk because they only work with certain clouds, which makes it that much harder to migrate to another cloud or extend into a multi-cloud architecture.
For these reasons, open source cloud monitoring tools are an attractive alternative. Their main advantages include:
- Cost. Open source monitoring tools are usually free to install and use.
- Agnosticism. Open source tools generally work with any type of environment or configuration.
- Data ownership. When you deploy open source monitoring software on infrastructure that you control, you retain full ownership over the data it collects. This is not always the case with commercial tools, which collect and store data on the vendor's infrastructure.
- Integrations. Most open source cloud monitoring tools are easy to integrate with other tools or services. This can be valuable if you want to pair the tool with another one that handle tasks such as data storage and visualizations.
The main downside to open source monitoring platforms is that they may be more difficult to deploy and manage. As a result, the indirect staff costs required to run them could be higher. It may also be difficult to obtain professional support for the tools, though many are backed by commercial companies that offer support services for a fee. Lastly, there can be great variety in the maturity of different open source monitoring tools -- some are not as feature-rich as others.
Five mature open source cloud monitoring tools
Despite some of the limitations, there are several open source cloud monitoring tools that are mature and ready for production use. Consider the following five options -- in no particular order -- when building a cloud monitoring strategy based on open source software.
First released in 2001, Zabbix is a tried-and-true monitoring tool with highly flexible configurations. It can collect cloud monitoring data using agents, which may be useful when monitoring cloud-based VMs. It also integrates with services like Amazon CloudWatch to collect metrics directly from cloud environments.
Zabbix can be somewhat difficult to set up, especially for monitoring cloud environments. IT originated long before anyone was talking about the cloud, so it wasn't designed to be simple to deploy as a cloud monitoring tool. Zabbix's ability to scale is also limited: It only supports up to 1,000 nodes.
If you need a highly customizable monitoring tool for small- to medium-sized cloud environments, Zabbix is a great fit. But it is harder to work with than other open source cloud monitoring software listed here, and it can't scale to support very large environments.
Nagios has many similarities to Zabbix. It's been around for nearly 20 years, making it a well-established monitoring tool. And it offers the same level of flexibility in terms of configurations and data collection.
A major difference between the two is that Nagios is available in two versions. Nagios Core is free, while Nagios XI is a paid platform that offers better usability and extra features. Zabbix comes in only one version. Nagios' dual-version model may be attractive if you think you may need more features than the free platform provides. In that case, start with Nagios Core and upgrade to Nagios XI if needed later.
If you need more features than Nagios Core offers, but you don't want to upgrade to Nagios XI, consider Icinga. Created in 2009 as a fork off of Nagios, Icinga offers many of the same features as Nagios Core but adds other capabilities to simplify monitoring and increase usability with features such as a more intuitive interface.
However, Icinga doesn't directly integrate with most cloud services, which could be a serious reason to avoid it. You can't collect data directly from CloudWatch, for example. Instead, Icinga imports data from workloads running in the cloud, such as VMs. This is fine, if your cloud environments consist mostly of basic components like VMs, but it is cumbersome if you need to monitor other types of cloud services, like serverless functions.
Grafana, which dates back to 2014, is a monitoring tool designed for the cloud age. Technically speaking, Grafana is, for the most part, a visualization tool. It needs to integrate with other tools to collect data, which it then displays in ways that simplify interpretation.
While this may seem to be a limitation, it is, in many respects, a strength because Grafana provides a great deal of flexibility in selecting a data collector. You can use another open source tool, like Prometheus, or you can collect it directly from a cloud service.
Grafana's biggest limitation is that it is not great in situations when you want to compare data from multiple clouds or a hybrid cloud. Grafana can only display data from one data source at a time. While it's possible to integrate multiple data sources to interpret them at the same time, doing so requires custom queries.
Still, Grafana stands apart from most other open source cloud monitoring tools in that it was built first and foremost for the cloud. And it, arguably, comes closest among all open source tools to delivering a seamless experience comparable to that of commercial alternatives.
Although Zenoss is slightly older than Grafana, it has also evolved into a cloud-focused monitoring tool. Not only does it monitor a variety of cloud services, but it also has predictive features designed to help teams understand what will happen in the future.
Zenoss Community Edition, the open source version of the platform, is free. Other versions, which offer additional features, cost money.
In its open source form, Zenoss' scalability is limited and it is more difficult to deploy. In this respect, Zenoss is comparable to Nagios, which also offers limited functionality, unless you upgrade to a paid version.