OpenTelemetry 101: A nontechnical guide for IT leaders and enthusiasts

If you work in software development, SRE, or DevOps, you’ve likely heard the terms observability, telemetry, and tracing. These concepts are crucial for understanding how applications behave in production environments, and they’re an essential part of modern software development practices.

You’ve also likely heard OpenTelemetry mentioned in the context of observability. In this article, we’ll cover OpenTelemetry 101: what it is, how it works, and why it’s important for modern software development. You’ll get a high-level overview of how to get started with OpenTelemetry and its key components.

What is OpenTelemetry?

OpenTelemetry is an open source observability project that encompasses a set of APIs, libraries, agents, and instrumentation standards. Using OpenTelemetry, developers can collect and process telemetry data from applications, services, and systems.

To understand what this means, let’s first look at two of the core concepts: observability and telemetry.

Observability

Observability is the ability to determine a system’s health by analyzing the data it generates, such as logs, metrics, and traces.

Unlike traditional monitoring, which focuses on watching individual metrics for system health indicators with no overall context, observability goes deeper, analyzing telemetry data for a comprehensive view of the system’s internal state in context of the wider system.

Telemetry

Telemetry involves collecting and analyzing data from distributed sources to provide insights into how a system is performing. There are three main types of telemetry data:

• Metrics. Quantitative measurements that track the performance and health of systems over time. Metrics are typically aggregated and stored in time series databases for monitoring and alerting purposes.
• Logs. Text-based records of events and activities generated by applications and infrastructure components. Logs are used for debugging, troubleshooting, and auditing purposes.
• Traces. Detailed records of the flow of requests through distributed systems, including timing information and contextual data. Traces are used for performance analysis, latency optimization, and root cause analysis.

OpenTelemetry 101

In this context, OpenTelemetry’s unified set of platform-agnostic APIs, libraries, agents, and instrumentation standards allows developers to collect, process, and visualize this telemetry data from applications. The OpenTelemetry Protocol (OTLP) plays a critical role in this framework by standardizing how systems format and transport telemetry data, ensuring that data is interoperable and transmitted efficiently. This standardization, in turn, enables comprehensive observability by integrating data for a holistic perspective and enabling proactive issue resolution.

Overall, OpenTelemetry offers the following advantages:

• Standardized data collection. It enhances observability by providing standardized tools and APIs for collecting, processing, and exporting metrics, logs, and traces.
• Interoperability and vendor neutrality. A common set of APIs and data formats ensures interoperability across different tools and platforms. This interoperability allows organizations to avoid vendor lock-in and switch between or integrate multiple observability tools without reinstrumenting their applications.
• Enhanced context and correlation. It enriches telemetry data with relevant attributes, aiding in the correlation of metrics, logs, and traces for a comprehensive understanding of system behavior.
• Integration with existing tools. It integrates with existing observability tools, enhancing data collection and analysis while providing standardized data formats for deeper insights and improved interoperability. For example, a company using a log aggregation tool can use OpenTelemetry to gain additional trace data without disrupting its setup, thus enabling a gradual and smooth transition from legacy systems to modern observability.
• Future-proof observability. It evolves continuously through contributions from a vibrant community and support from major tech companies, which ensures that it stays aligned with the latest industry standards, technological advancements, and best practices.

OpenTelemetry components

OpenTelemetry is composed of several key components, including tracers, instrumentation libraries, and the OpenTelemetry Collector.

Tracers and instrumentation

Tracers in OpenTelemetry track the flow of requests through different parts of an application, similar to tracking a package from one postal center to another. They record the journey of data through services to help identify where delays or issues occur.

Instrumentation involves adding code to your application to collect this tracking information, akin to installing security cameras in a store to monitor customer movement and behavior. Depending on the language and framework of your application, you’ll be working with a number of different instrumentation libraries.

Both tracers and instrumentation libraries are essential components for collecting and recording insights on application performance. While traces actively record and follow the path of data through an application, instrumentation libraries provide the necessary code to easily integrate these tracers and other telemetry data collection mechanisms into an application.

Metrics and logs

Metrics are numerical data points that measure an application’s performance. Think of metrics as an application’s vital signs, like heart rate or blood pressure in a health checkup. They tell you things like how many users are accessing the service, how long requests take, or how much memory the application uses.

Logs are detailed records of events that happen within an application. It’s similar to keeping a diary where you note down every significant event of your day. Logs do this for applications by recording errors, transactions, and other important actions. They provide context and details that help you diagnose problems when things go wrong.

The OpenTelemetry Collector

The OpenTelemetry Collector is a centralized service that gathers an applications’ telemetry data (metrics, logs, and traces). It’s like a postal sorting center that collects mail from different places, organizes it, and then sends it to the right destination. The Collector can process this data, filter out unnecessary information, and send useful insights to various monitoring and analysis tools.

Getting started with OpenTelemetry

Getting started with OpenTelemetry involves installing the appropriate libraries and agents for your programming language and environment. OpenTelemetry supports a variety of languages, including Java, Python, JavaScript, and more, making it accessible to most applications. A full list of the supported frameworks and languages can be found at the OpenTelemetry Registry.

The installation process typically includes adding OpenTelemetry dependencies to your project and initializing the OpenTelemetry software development kit (SDK). The OpenTelemetry website provides detailed documentation for each language to guide you through the necessary steps to set up your environment.

Configuring OpenTelemetry for your applications

Once you install the libraries, the next step is to configure OpenTelemetry to collect telemetry data from your applications. This involves setting up instrumentation to capture metrics, logs, and traces. You can set up instrumentation manually by adding specific code snippets to your application, or automatically using OpenTelemetry auto-instrumentation agents.

You’ll also need to configure exporters, which determine where OpenTelemetry will send the data it collects for analysis. Common exporters include Prometheus for metrics, Jaeger for traces, and Elasticsearch for logs. Configuration files or environment variables are typically used to set these parameters, making it straightforward to adapt the setup to your specific needs.

Depending on your use case, you can customize sampling rates, filtering rules, and other settings to optimize data collection and analysis. OpenTelemetry provides extensive documentation and examples to help you fine-tune your configuration for maximum effectiveness.

Best practices for implementing OpenTelemetry

To maximize the benefits of OpenTelemetry, follow the best practices outlined below.

Start small and incremental

Begin with a pilot project or a single service to validate your setup and understand the data being collected. This approach allows you to test and refine configurations, manage implementation complexity, and demonstrate value to stakeholders.

Focus on relevant telemetry data

Ensure you’re collecting the right type of telemetry data for effective observability by focusing on specific use cases and questions:

• Identify key metrics. Capture critical performance indicators such as request latency, error rates, and resource usage.
• Contextualize data. Add relevant context to telemetry data, like service names, environment tags, and custom attributes.
• Employ efficient sampling. Use trace sampling to manage data volume without losing essential insights.

Ensure security and data privacy

To avoid leaking sensitive information through telemetry data, you should ensure telemetry data is encrypted in transit and at rest using protocols like TLS. You must also implement robust access controls to restrict who can view and manage telemetry data and anonymize or redact sensitive information before sending telemetry data. These practices not only protect sensitive information but also maintain compliance with data privacy regulations.

Implement efficient sampling techniques

Implement efficient sampling techniques to manage data volume. For example, you can use trace sampling to capture a representative subset of traces and gather enough information to diagnose issues effectively.

Aggregate metrics at the source

Reduce data volume and processing overhead by aggregating metrics at the source. Aggregating metrics within your application or at the edge will minimize the amount of data sent to observability backends.

Leverage existing tools

Integrate OpenTelemetry with existing logging and tracing tools to enhance your current monitoring infrastructure. OpenTelemetry can complement and extend your existing observability tools to ensure a unified and effective strategy.

OpenTelemetry use cases

There are several use cases for OpenTelemetry, including:

• Monitoring and troubleshooting distributed systems. OpenTelemetry provides end-to-end visibility in distributed systems by capturing detailed traces of requests across multiple services. For example, if a user experiences slow response times in an e-commerce application, OpenTelemetry can trace the request through various microservices to pinpoint the service causing the delay. This visibility simplifies troubleshooting and allows IT teams to quickly identify and resolve issues, minimizing downtime and improving system reliability.
• Performance optimization. By collecting and analyzing metrics and traces, OpenTelemetry helps identify system inefficiencies. For instance, if an application is experiencing high latency, OpenTelemetry can reveal that a specific database query is taking too long to execute. This data-driven approach enables IT teams to optimize slow-performing components, thus enhancing application efficiency and user experience.
• Integration with existing tools. OpenTelemetry integrates seamlessly with existing observability tools, exporting telemetry data to monitoring and analytics platforms. For example, an organization using Prometheus for monitoring can incorporate OpenTelemetry to gain additional trace data to enrich its observability strategy. This interoperability allows organizations to enhance their current monitoring infrastructure with comprehensive telemetry data, ensuring a unified and effective observability strategy.

The future of OpenTelemetry

OpenTelemetry is rapidly evolving, with continuous updates, enhancements, and contributions from a vibrant community of developers and organizations, and more importantly, it keeps getting wider adoption.

The best way to stay up-to-date with OpenTelemetry is to follow the project’s public roadmap, which outlines upcoming features, improvements, and initiatives.

That said, one of the most exciting features will be the client instrumentation project which will allow developers to have true end-to-end visibility into their application latency and performance. With traditional monitoring and logging, you often get a siloed view of the application performance, but this development will allow you to see the application performance from the browser interaction all the way through the system’s backend.

OpenTelemetry 101: Flexible, customizable telemetry gathering for comprehensive observability

OpenTelemetry is a standard way for organizations to create, gather, and customize metrics, traces, and logs for more comprehensive insights into system behavior. Using this standardized approach to telemetry data, developers gain greater observability of their systems and can become more proactive by continuously analyzing system behavior and identifying anomalies before they’re critical issues.

Additionally, because OpenTelemetry is open source, you can avoid vendor lock-in. This vendor neutrality makes OpenTelemetry future-proof as developers create new tools and libraries. Above all, it’s an effective approach for enabling analysis across a variety of observability backends.