OTLP Receiver to OTLP Exporter: Does the OpenTelemetry Collector preserve incoming W3C tracestate entries unchanged?

The goal is to confirm whether an OpenTelemetry Collector, when receiving spans through an OTLP receiver from an SDK‑instrumented service, forwards the original W3C traceparent and tracestate headers unchanged via its OTLP exporter to a downstream backend. This concerns the preservation of trace context across the Collector boundary.

The OTLP specification defines how span context is encoded but does not require the Collector to normalize or retain every tracestate entry. Consequently, handling of malformed, duplicated, or excessively large tracestate values may differ depending on the Collector version, the specific contrib exporter in use, and the language SDK that generated the incoming span.

Does the Collector drop tracestate entries that fail syntactic validation?

Does it deduplicate identical tracestate key‑value pairs before re‑injection?

When the combined tracestate size exceeds an internal limit, are excess entries truncated, discarded, or does the export fail?