Manual Instrumentation
Manual instrumentation is a software development practice where developers explicitly add code to their applications to collect performance metrics, trace requests, and monitor behavior for observability purposes. It involves inserting custom logging, timing, and monitoring calls at strategic points in the codebase to track execution flow, latency, errors, and other key indicators. This approach provides fine-grained control over what data is collected and how it is structured, enabling detailed insights into application performance and health.
Developers should use manual instrumentation when they need precise, application-specific observability that automated tools cannot provide, such as tracking custom business logic, monitoring specific user journeys, or debugging complex distributed systems. It is particularly valuable in performance-critical applications, microservices architectures, and scenarios requiring detailed traceability for compliance or optimization, as it allows tailoring metrics to exact requirements without relying on generic auto-instrumentation.