In 2023, OpenTelemetry announced that it achieved stability for logs, metrics, and traces. By 2024, the community has decided to extend Otel into profiling, the fourth pillar of observability.
Bringing all four pillars of observability together creates a link among Logs, Metrics, Traces, and Profiling telemetry.
- Metrics to profiles: You will be able to go from a spike in CPU usage or memory usage to the specific pieces of the code which are consuming that resource
- Traces to profiles: You will be able to understand not just the location of latency across your services, but when that latency is caused by pieces of the code it will be reflected in a profile attached to a trace or span
- Logs to profiles: Logs often give the context that something is wrong, but profiling will allow you to go from just tracking something (Out Of Memory errors, for example) to seeing exactly which parts of the code are using up memory resources
