If you were to make a list of major buzzwords du jour from the monitoring and observability space, it would almost certainly include OpenTelemetry and eBPF. Both technologies have become important sources of innovation in recent years for helping IT teams monitor and observe applications and services efficiently.
That said, OpenTelemetry and eBPF work in different ways and offer different pros and cons. Whether IT teams should take advantage of one technology, the other, or both depends on what they need to monitor and which types of monitoring data is most important to them.
With that reality in mind, let's break down the similarities and differences between OpenTelemetry and eBPF and discuss what to use when.
What Is OpenTelemetry?
OpenTelemetry is an open, vendor-neutral collection of tools and frameworks that businesses can use to help capture observability data from applications. By including OpenTelemetry instrumentation libraries in application code, then monitoring applications using OpenTelemetry-compliant tools, IT organizations can collect the data they need to help monitor and manage virtually any type of software.
The big idea behind OpenTelemetry is to standardize the way monitoring happens. No matter which types of applications you need to monitor or which types of monitoring data and logs you want from them, OpenTelemetry provides a consistent way to get it.
What Is eBPF?
The extended Berkeley Packet Filter, or eBPF, is a technology that makes it possible to run programs inside the Linux kernel without having to modify kernel source code or load kernel modules.
Using eBPF programs, IT teams can run code that collects data from applications and infrastructure. (They can also use eBPF for other tasks beyond monitoring, such as enforcing security rules.) Because the code runs inside the kernel, it's hyper-efficient. It's also very secure because eBPF programs are sandboxed from each other and have to pass validations before the kernel allows them to run.
OpenTelemetry vs. eBPF
So, at a high level, OpenTelemetry and eBPF serve the same core purpose: They streamline monitoring and observability workflows for modern applications.
If you look under the hood, however, you will realize that OpenTelemetry and eBPF do this in different ways. The key differences between OpenTelemetry and eBPF include:
- Implementation: To use OpenTelemetry, you have to integrate OpenTelemetry instrumentation into your applications. In contrast, eBPF programs run independently of applications, so there is no need to modify the applications themselves in order to use eBPF.
- Efficiency: Compared with OpenTelemetry, eBPF programs can in most cases collect data with lower levels of CPU and memory usage because they run directly in the kernel.
- Compatibility: Currently, eBPF works only with Linux-based workloads. (Development of a version of eBPF for Windows is underway, but it's not currently fully mature.) In contrast, OpenTelemetry works across most mainstream operating systems.
- Ease of use: In its current state, OpenTelemetry is, on the whole, easier to use than eBPF. That's because OpenTelemetry has been integrated into a wide range of application monitoring tools, whereas only a handful support eBPF. This means that getting up and running with eBPF will typically require more effort than using OpenTelemetry.
What to Use When: OpenTelemetry vs. eBPF
So, which observability solution should you use?
In general, the answer is that eBPF works best when performance is a key priority and when you lack the development resources to instrument OpenTelemetry inside your applications. You also, again, need to be running your workloads on Linux if you want to use eBPF.
On the other hand, OpenTelemetry makes more sense if you are creating new applications and can design them from the start to support the OpenTelemetry framework. It's also ideal for IT organizations that need to support both Windows- and Linux-based workloads.
Keep in mind, too, that OpenTelemetry and eBPF are not an either-or proposition. It's possible to use both of them at the same time, even for the same applications — which you might choose to do if, for example, you've already instrumented OpenTelemetry for an app but the resource consumption levels of your monitoring tools are too high, so you want to offload some of the monitoring work to eBPF programs.
About the author
Christopher Tozzi is a technology analyst with subject matter expertise in cloud computing, application development, open source software, virtualization, containers and more. He also lectures at a major university in the Albany, New York, area. His book, “For Fun and Profit: A History of the Free and Open Source Software Revolution,” was published by MIT Press.
