DevOps Tools Introduction #15: Tracing
Throughout the last few months, we’ve explored new topics each and every week in our DevOps Tools Introduction series. We’ve reached the last lesson, which introduces yet another topic a DevOps professional should know.
Modern distributed systems introduce a level of complexity that makes traditional monitoring approaches insufficient. When applications are decomposed into microservices, each request may traverse multiple services, networks, and infrastructure layers. In this context, distributed tracing becomes an essential capability for understanding system behavior, diagnosing issues, and improving performance.
This article introduces the core concepts of tracing, explores the fundamentals of OpenTelemetry, and provides an overview of commonly used open source telemetry analysis tools, along with key ideas around application instrumentation.
What is Tracing?
Tracing follows the lifecycle of a request as it propagates through different components of a distributed system. Unlike logs, which provide discrete events, or metrics, which provide aggregated data, tracing offers a causal view of how operations are executed across services.
Some definitions are useful before examining OpenTelemetry, the main open source tool used in tracing. A distributed trace represents the complete journey of a request. It is composed of multiple spans, where each span represents a unit of work performed by a service or component. Spans are organized hierarchically, forming a tree-like structure that reflects the relationships between operations.
Each trace is uniquely identified by a trace ID, while each span within that trace has its own span ID. These identifiers allow the system to correlate events across service boundaries.
A span typically contains:
- Timing information (start and end time)
- Metadata about the operation
- Relationships to parent and child spans
This structure enables engineers to visualize latency, identify bottlenecks, and understand dependencies between services.
Key Elements of Distributed Traces
To effectively work with tracing systems, it is important to understand the core elements that define spans and traces.
Span attributes are key-value pairs that provide contextual information about the operation, such as HTTP method, database query, or user ID. They enrich traces and make analysis more meaningful.
Events represent time-stamped annotations within a span, often used to capture significant occurrences during execution, such as retries or errors.
Links connect spans that are causally related but do not follow a strict parent-child relationship, which is useful in asynchronous or batch processing scenarios.
Status indicates the outcome of a span, such as success or error, and may include error descriptions.
Kind defines the role of the span, such as client, server, producer, or consumer, helping to clarify how the operation fits into the overall system.
Context Propagation
One of the most critical aspects of distributed tracing is context propagation. As a request moves across services, the tracing context must be passed along to ensure continuity of the trace.
This context includes the trace ID, span ID, and additional metadata. Without proper propagation, traces become fragmented, making it difficult to reconstruct the full execution path.
In practice, context is often propagated through HTTP headers or messaging systems, ensuring that each service can attach its spans to the correct trace.
OpenTelemetry
OpenTelemetry is an open source observability framework that provides a unified standard for collecting traces, metrics, and logs. It is a project managed by the Cloud Native Computing Foundation (CNCF) and has become the de facto standard for telemetry instrumentation in modern systems.
OpenTelemetry defines:
- APIs for generating telemetry data
- SDKs for processing and exporting data
- Semantic conventions for consistent naming and structure
By adopting OpenTelemetry, organizations can avoid vendor lock-in and ensure interoperability between different observability tools.
Instead of integrating directly with specific backends, applications instrumented with OpenTelemetry can export telemetry data to multiple systems, such as tracing backends, metrics platforms, or log aggregators.
Application Instrumentation
Application instrumentation refers to the process of modifying code to generate telemetry data. This can be done in two primary ways: manual instrumentation and automatic instrumentation.
Manual instrumentation involves explicitly creating spans and adding attributes in the application code. This approach provides fine-grained control but requires developer effort.
Automatic instrumentation uses libraries or agents that automatically generate spans for common frameworks and protocols, such as HTTP servers, database clients, and messaging systems. This approach reduces effort and accelerates adoption.
Effective instrumentation should focus on capturing meaningful operations, avoiding excessive noise while ensuring sufficient visibility into system behavior.
Open Source Telemetry Analysis Tools
Once telemetry data is collected, it must be stored, queried, and visualized. Several open source tools are widely used for this purpose.
Jaeger is a popular distributed tracing system originally developed by Uber. It provides powerful capabilities for trace visualization, dependency analysis, and performance monitoring.
Grafana Tempo is a high-scale tracing backend designed for efficiency and integration with the Grafana ecosystem. It emphasizes cost-effective storage by indexing only metadata while storing traces in object storage.
These tools allow engineers to explore traces, identify latency issues, and understand how requests flow through complex systems.
Why Tracing Matters
Tracing provides visibility into the internal workings of distributed systems that cannot be achieved with logs or metrics alone. It enables teams to:
- Diagnose performance bottlenecks
- Understand service dependencies
- Troubleshoot failures across multiple components
- Improve system reliability and user experience
As systems continue to grow in complexity, tracing becomes not just a useful tool, but a fundamental requirement for effective operations.
Understanding tracing, OpenTelemetry, and telemetry analysis tools is essential for anyone working with modern cloud-native systems. By instrumenting applications and adopting standardized observability frameworks, teams gain the ability to see what was previously invisible.
Tracing transforms how we understand systems—from isolated events to complete, end-to-end visibility—enabling more informed decisions and more resilient architectures.
Make sure to explore the official Learning Material for the DevOps Tools Engineer certification, available at no cost. It offers comprehensive coverage of the exam objectives and serves as a valuable guide to support and structure your studies.
