Correlation id
A correlation ID is an identifier associated with related messages, events, or operations so they can be linked across components of a system.
Secure APIs
A trace ID is an identifier shared by telemetry records belonging to the same request execution or distributed processing path.
- How it is used
- Correlates telemetry from one API request for observability, debugging, and cybersecurity investigation.
- How deep it goes
- Explains request and distributed-service correlation, then demonstrates shared context in OpenTelemetry span logs and custom spans.
- Examples
- Uses GET /books span logs, distributed quote processing, and a POST /carts custom span with user and cart attributes.
- What you can do after
- Diagnose and debug requests with OpenTelemetry by searching a trace ID and creating correlated custom spans.
Go by Example
A trace ID is an identifier that correlates processing and log records belonging to the same request or distributed operation.
- How it is used
- Correlates HTTP request logs by propagating one request-scoped identifier through Context.
- How deep it goes
- Explains generation, Context storage, middleware propagation, and slog.Handler record enrichment, while deferring robust UUID generation.
- Examples
- Demonstrates a traceid package, HTTP middleware, LogHandler wrapper, and /health request logs carrying trace_id.
- What you can do after
- Apply it via net/http middleware and log/slog handlers to emit correlated request logs automatically.
gRPC Microservices in Go
A trace ID is an identifier that correlates all operations belonging to one distributed request.
- How it is used
- Groups activity from one distributed request so operators can inspect cross-service logs and request latency.
- How deep it goes
- Shows how to inject trace and span IDs into Go logs; mentions event correlation without implementing event propagation.
- Examples
- Uses an order-creation log entry and payment-command events with a reply channel.
- What you can do after
- Apply it via logrus and OpenTelemetry context to tag logs with identifiers for filtering one operation.
Kafka for Architects
A correlation ID is an identifier carried with related request and response messages so they can be matched.
- How it is used
- Matches requests with replies in request-response messaging across Kafka and RabbitMQ.
- How deep it goes
- Defines header-based matching and explains response-routing and lost-context problems, without detailing a complete recovery implementation.
- Examples
- Uses a CORRELATION_ID header in Kafka services and matching IDs on RabbitMQ request-reply queues.
- What you can do after
- Understand how a shared identifier pairs a reply with its request and why routing it to the originating service instance matters.
Cloud Observability in Action
A trace identifier is the identifier shared by spans belonging to one distributed request trace.
- How it is used
- Uses a shared request identifier to correlate spans, metrics, and logs during distributed-service investigation.
- How deep it goes
- Defines propagation and correlation, but defers detailed span-emission implementation.
- Examples
- Demonstrates metric exemplars linking to Jaeger traces during an error-rate investigation.
- What you can do after
- Diagnose distributed failures by navigating from a metric exemplar to traces and associated logs.
Read how Cloud Observability in Action explains correlation id →
Related concepts
- trajectoryused by · A trajectory is an ordered sequence of states, actions, events, or operations that records or describes progression through successive steps or over time.
- request-response APIused by · A request-response API is an interaction pattern in which a requester sends a request to a provider and receives a corresponding response.
- loguses · A log is a record of events, activity, or diagnostic information produced during the operation of a system or process, often ordered by time.
- spanhas part · A span is a record of an individual operation within a trace, typically including its timing, context, outcome, and relationships to other operations.
- contextuses · In Go, context.Context is an interface carrying cancellation signals, deadlines, and request-scoped values across function and service boundaries.
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