What is OpenTelemetry (OTel), why is it needed, and what does it look like?

OpenTelemetry (OTel) is an open standard and a set of tools for collecting telemetry data (traces, metrics, logs) from distributed systems. It helps developers and operators understand application behavior, identify bottlenecks, and troubleshoot errors.

Why is it needed:

• Unification of data collection from different services and languages.
• Ensuring compatibility with various monitoring and tracing systems.
• Simplifying diagnostics and performance analysis.

What it looks like:

• SDKs for different programming languages that allow instrumenting code.
• APIs for creating and sending trace and metric data.
• Exporters that send data to monitoring systems (Jaeger, Prometheus, Zipkin, etc.).

Example in Go for creating a span (trace):

import (
    "context"
    "go.opentelemetry.io/otel"
    "go.opentelemetry.io/otel/trace"
)

func main() {
    tracer := otel.Tracer("example-tracer")
    ctx, span := tracer.Start(context.Background(), "operation-name")
    defer span.End()

    // Your code here
}

Thus, OpenTelemetry helps collect and analyze application data in a unified format.