Errors, traces, logs, metrics: when to reach for what
Blog post from Sentry
Errors, traces, logs, and metrics are four fundamental telemetry tools used in application instrumentation, each serving distinct purposes and workflows. Errors help identify what broke, traces monitor request flows and timing, metrics track trends over time, and logs capture the state of the system at specific moments. While these signals can overlap, each is tailored to answer different questions and support various workflows, and their effectiveness depends on how they are used and integrated. In Sentry, these telemetry tools are unified under one SDK, facilitating seamless instrumentation and correlation by sharing a trace_id. This integration allows developers and AI agents to optimize code paths and identify issues effectively by providing structured data, which can be queried and analyzed to understand and improve application performance.