OpenTelemetry — SDK instrumentation, OTLP protocol and collector — CI/CD, GitOps, DevSecOps & Observability

Observability is the ability to understand the internal state of a system from its external outputs. The three pillars of observability are metrics—numeric time-series measurements like request rate and error rate—logs—structured or unstructured text records of discrete events—and traces—causal chains of spans that describe how a request propagates across services. OpenTelemetry is the CNCF-graduated vendor-neutral standard for collecting and exporting all three signals from applications and infrastructure.

Before OpenTelemetry, every observability vendor required proprietary instrumentation libraries. Switching from Datadog to Prometheus required rewriting all telemetry code throughout the application codebase. OpenTelemetry solves this with a single instrumentation API that decouples the application code from the observability backend: the application emits telemetry using the OTel SDK, the OpenTelemetry Collector routes that telemetry to any backend, and switching backends requires only a Collector configuration change—no application code changes.

Analogy🏏Cricket

Think of it like cricket: Imagine the BCCI's team management system for an international tour with matches in three different countries simultaneously. Rather than a coordinator manually managing each match day's logistics, the system reads the official tour schedule document and automatically dispatches the right squad, equipment, and support staff to each venue. When the tour schedule changes—a match is rescheduled, a squad member is replaced—the system detects the change and updates the arrangements automatically. Just as the tour management system uses the official document as the source of truth and orchestrates multiple concurrent deployments to multiple venues, ArgoCD uses the Git repository as the source of truth and orchestrates multiple concurrent Application syncs to multiple clusters. Just as the system provides a dashboard showing which venues are 'ready', 'delayed', or 'degraded', ArgoCD provides a dashboard showing which Applications are Synced, OutOfSync, or Degraded. This reveals why ArgoCD is valued at scale: managing dozens of applications across multiple clusters manually is operationally equivalent to coordinating an international cricket tour by phone.