Top 15 OpenTelemetry Questions Answered

If you're just starting out with OpenTelemetry, you're in the right place. Whether you’re a developer or an operations engineer, understanding OpenTelemetry is key to unlocking powerful observability across your systems. Let’s answer your most asked questions.

What is OpenTelemetry?

OpenTelemetry is an open-source set of APIs, libraries, and tools for collecting, processing, and exporting telemetry data from your applications. It provides a unified approach to gathering traces, metrics, and logs, helping you monitor the performance of your systems with less hassle.

Why Should I Use OpenTelemetry?

OpenTelemetry simplifies the process of observability by offering a standardized framework that works with many different backends. Instead of relying on multiple, disconnected monitoring tools, you can use OpenTelemetry to collect and export data consistently across various systems.

What Are the Key Components of OpenTelemetry?

OpenTelemetry isn’t just a framework; it’s made up of several components that work together to give you a comprehensive observability solution.

Here’s a breakdown:

1. API

The API defines how to collect telemetry data. As a developer, you’ll interact with this API to instrument your code and start tracking things like traces and metrics.

2. SDK

The SDK is the implementation of the API, responsible for actually generating and exporting telemetry data. It connects your application’s telemetry to external observability platforms like Prometheus or Jaeger.

3. Collector

The OpenTelemetry Collector is a component that aggregates and processes telemetry data before exporting it to backends. It acts as a proxy, taking care of things like batching and transforming data, making it easier to manage observability at scale.

4. Instrumentation Libraries

OpenTelemetry provides pre-built instrumentation libraries for popular frameworks and libraries. These let you quickly add observability to your application without needing to do much custom work.

What Are the Main Types of Telemetry Data?

OpenTelemetry helps you collect three main types of telemetry data: traces, metrics, and logs. Let’s break each down:

1. Traces: What Are They and Why Do They Matter?

Traces track the flow of a single request across your system, giving you a detailed view of how it moves through different services. They are invaluable for debugging performance bottlenecks and identifying where failures occur in a distributed system.

2. Metrics: How Do They Help You Monitor Performance?

Metrics give you a quantitative view of your system’s health. You can measure things like latency, throughput, and error rates. This data is essential for spotting trends, such as a slow increase in latency or an uptick in errors, so you can take action before things go wrong.

3. Logs: What Role Do Logs Play in Observability?

Logs are more granular than metrics or traces. They record specific events in your application, such as errors, warnings, or status changes. Logs help you troubleshoot issues by providing contextual information that can guide your debugging efforts.

What Should I Instrument First with OpenTelemetry?

When you first start with OpenTelemetry, it's best to begin with the most critical parts of your application, such as:

• Key APIs and Services: These are the core parts of your application that handle most of the traffic or business logic.
• User Authentication/Authorization: Instrumenting user login and permission-checking processes help you trace access-related issues.
• Database Calls: These often cause performance bottlenecks, so tracking database query performance can yield helpful insights.
• External APIs: Any third-party API calls your app makes should be traced for performance monitoring.

Starting here ensures that you have visibility into the most important components first.

Can I Use OpenTelemetry Without the Collector?

Yes, you can use OpenTelemetry without the Collector. In simple setups, you can configure your SDK to export data directly to your chosen observability backend (e.g., Jaeger, Prometheus, or even Last9). The Collector is optional but highly recommended for production environments, as it provides a central point for processing and exporting data.

Can the OpenTelemetry Collector Handle Millions of Requests Per Second?

Yes, the OpenTelemetry Collector can handle millions of requests per second, but it depends on the configuration and infrastructure. It’s designed to be scalable and can be tuned for performance to handle high-throughput environments. For extremely high loads, consider running the Collector in a distributed setup and configuring batching, filtering, and load balancing to ensure optimal performance.

What Are Common Issues When Setting Up OpenTelemetry?

When setting up OpenTelemetry, some common challenges include:

• Incorrect Instrumentation: Failing to instrument key parts of your application can result in missing telemetry data.
• Data Volume: Handling large volumes of telemetry data can overwhelm your observability backend if not properly configured.
• Incompatible Backends: Ensure your chosen backend supports OpenTelemetry; some may require specific configuration.
• Configuration Complexity: OpenTelemetry offers a lot of customization, but the complexity can lead to misconfiguration if you’re new to it.

How Should I Manage Attributes in Telemetry Data?

Attributes help provide context for your telemetry data. When managing them, follow these guidelines:

• Keep Them Consistent: Ensure your attribute names and values are standardized across your application for consistency.
• Use Meaningful Names: Use clear, descriptive names for attributes (e.g., http.status_code, db.query_time) so they are easily understandable.
• Limit Cardinality: High-cardinality attributes (like user IDs or session tokens) can increase storage costs and complexity, so try to avoid overusing them.
• Use Structured Data: For complex data, use structured attributes (like JSON objects) to store more detailed context.

How Do I Install OpenTelemetry Collector?

To install the OpenTelemetry Collector, follow these basic steps:

1. Download the Collector: You can download the pre-built binary or use Docker for containerized setups.
2. Configure the Collector: Define the pipelines (e.g., traces, metrics, logs) and set up the exporters to your backend.
3. Run the Collector: Start the Collector using your chosen method (e.g., as a service, via Docker, etc.).

For detailed installation steps, refer to the OpenTelemetry Collector guide.

What Tools Support OpenTelemetry?

OpenTelemetry is widely supported by many tools and services, including:

• Backends: Jaeger, Prometheus, Zipkin, and Last9 (for OpenTelemetry-native observability).
• Cloud Providers: AWS, GCP, and Azure support OpenTelemetry integrations.
• Libraries/Frameworks: Popular frameworks like Spring, Express, Django, and Flask have built-in OpenTelemetry instrumentation libraries.
• Visualization Tools: Grafana, Kibana, and others can integrate with OpenTelemetry for visualizing traces, metrics, and logs.

What Is the Best Practice for Batching Telemetry Data?

Batching helps improve the efficiency of your telemetry pipeline by grouping telemetry data into batches before sending it to the backend. Best practices for batching include:

• Adjust Batch Size: Set an optimal batch size based on your infrastructure’s performance and the backend's ingestion capabilities.
• Control Batch Interval: Set a reasonable time interval for sending batches to avoid too frequent or too infrequent data exports.
• Use Asynchronous Processing: Asynchronous batch processing can reduce the impact on your application’s performance.

What Causes Data Latency in OpenTelemetry and How Can It Be Troubleshoot?

One common challenge with OpenTelemetry is latency in trace data, which can be caused by several factors:

• Network Delays: Long network paths between your app and the observability backend can introduce delays.
• Backlog in Exporters: If your exporters are overwhelmed, it can result in delayed telemetry data.
• Collector Overload: If you're using the OpenTelemetry Collector, ensure it’s configured properly to handle the load.

To resolve latency issues, consider optimizing the batch size, using compression for data transmission, or scaling the Collector to handle more requests.

How Can High Cardinality in OpenTelemetry Traces Be Managed Effectively?

High cardinality occurs when there are too many unique attribute values in traces, such as user IDs, session tokens, or request paths. This can overwhelm your backend and increase storage costs.

To manage high cardinality:

• Filter or Aggregate Data: Reduce the number of attributes tracked by using filters or aggregations.
• Limit Dynamic Attributes: Avoid dynamically generated attributes unless absolutely necessary.
• Use Sampling: In high-traffic applications, consider implementing trace sampling to reduce the volume of trace data being collected.

How to Troubleshoot and Resolve Data Loss in OpenTelemetry?

Data loss can happen if your telemetry data isn’t being exported or collected properly. Some potential causes and solutions include:

• Exporter Failures: Check if your exporters are failing or timing out, especially during peak traffic.
• Buffer Overflow: If the collector or SDK buffers become full, data may be dropped. Consider increasing buffer sizes or batch sizes to avoid this.
• Network or Backend Failures: Ensure that network connections to the backend are stable, and your backend is properly configured to handle incoming data.