How to implement distributed log tracing across multiple services?

Distributed tracing allows tracking requests passing through multiple microservices by linking logs and metrics into a single chain.

Main implementation steps:

1. Implementing a unique trace identifier (trace ID): When a request comes in, a trace ID is generated and passed between services via HTTP headers or other protocols.

2. Creating spans: Each service creates spans — individual operations with start and end timestamps, linked to the trace ID.

3. Data collection and aggregation: Spans are sent to a tracing collection system (e.g., Jaeger, Zipkin, OpenTelemetry Collector).

4. Visualization and analysis: Tools visualize call chains, helping identify bottlenecks and errors.

Example using OpenTelemetry in Java:

// Initialize tracing
Tracer tracer = OpenTelemetry.getTracer("exampleTracer");

// Create a span
Span span = tracer.spanBuilder("operationName").startSpan();
try {
    // Service logic
} finally {
    span.end();
}

It is important to ensure the transfer of tracing context between services, for example, via HTTP headers traceparent and tracestate according to W3C Trace Context.