OpenTelemetry Span JSON Generator

A span records one operation inside a distributed trace: it carries a name, an identifier of its own, the identifier of the trace it belongs to, a kind and an outcome. Chained by the same trace identifier, spans reconstruct a request's path across several services — which is the whole reason distributed instrumentation exists.

Fill in the name and, if you already have one, the trace identifier, and the page assembles the span as JSON. The sizes are not negotiable: the trace identifier is 16 bytes, or 32 hexadecimal digits, and the span identifier is 8 bytes, or 16 digits. An identifier of the wrong length is dropped by the collector, and an all-zero identifier is explicitly invalid in the specification.

The natural use is assembling an example to test a collector or an exporter configuration without instrumenting a whole application. Worth noting what a minimal span leaves out: the start and end timestamps, the attributes, the events and the parent span identifier — the last of which forms the tree. A span with no parent is the root of the trace.