opentelemetrylisted

# OpenTelemetry ## Span Naming Use short, low-cardinality names from semantic conventions: - HTTP: `GET /users/{id}` (method + route template, never full URL path) - DB: `SELECT users` (operation + table) - RPC: `grpc.health.v1.Health/Check` - Messaging: `orders process` (destination + operation) ## Attributes Use [semantic convention](https://opentelemetry.io/docs/specs/semconv/) attribute names — never invent your own: - HTTP: `http.request.method`, `url.full`, `http.response.status_code`, `server.address` - DB: `db.system`, `db.statement`, `db.namespace` - General: `error.type`, `service.name` Import from the versioned semconv package (e.g., `go.opentelemetry.io/otel/semconv/v1.x`). ## Status Only set status on errors: `span.SetStatus(codes.Error, err.Error())`. Never set `Ok` — unset is the success state. Call `RecordError` alongside `SetStatus`; it only adds a span event, doesn't change status. For HTTP: 4xx is `Error` on client spans, `Unset` on server spans. 5xx is always `Error`. ## Testing Use in-memory exporters with `SimpleSpanProcessor` (not batch — batch introduces timing). Assert on exported spans' names, attributes, and status. No mocking needed. ## Boundaries Instrument network calls, I/O, and queue operations — not every function. Use span events (`AddEvent`) instead of separate log statements for events within a traced operation.