Cloudflare Traces: Proxy Insights to OpenTelemetry Spans

Bridging the Proxy Observability Gap

Cloudflare's move to expose its proxy layer as OpenTelemetry spans is a substantial step forward for distributed tracing, addressing a long-standing blind spot for developers. Previously, understanding what happened within the proxy infrastructure – security rules, transformations, routing decisions – required inferring behavior from logs, a cumbersome and often incomplete process. By automatically generating spans for these components, Cloudflare provides developers with granular visibility into the request path, enabling them to pinpoint performance bottlenecks and diagnose issues with unprecedented accuracy. The integration with W3C trace context propagation further enhances its utility, allowing traces to flow seamlessly across different services and infrastructure components, creating a more holistic view of system behavior.

The shift in pricing from per-span to volume-based ingestion and retention is a critical change. While a move to volume-based pricing is common in observability platforms and can be more predictable for high-volume, low-granularity tracing, it introduces new considerations. Developers will need to carefully manage their sampling strategies to balance the need for detailed insights with cost control. The ability to define sophisticated Trace Rules for sampling, targeting specific traffic patterns or debugging scenarios, becomes paramount. However, the current limitations, such as the absence of automatic instrumentation for certain Cloudflare features like DDoS rules and Access, and the planned but not yet implemented authenticated context propagation, indicate that the observability story is still evolving. The promise of broader automatic instrumentation and richer context propagation in the future is exciting, but immediate adoption will necessitate a clear understanding of current coverage and pricing implications.

Key Points

• Cloudflare Traces is now in open beta, extending automatic tracing to the entire request path beyond Workers.
• New spans are automatically generated for security rules, transformations, cache decisions, routing, and origin handling, appearing as OpenTelemetry spans.
• This addresses a significant gap in distributed tracing by providing visibility into the proxy layer without manual instrumentation.
• Context propagation is supported, allowing Cloudflare spans to join upstream traces and forward trace context downstream.
• Sampling is controlled via a rules engine, enabling fine-grained control over which requests are traced for cost management and targeted debugging.
• Spans are exported via OTLP to any compatible backend, emphasizing Cloudflare's commitment to OpenTelemetry and data portability.
• Pricing has shifted from per-span to volume-based ingestion and retention, with specific free and paid tiers and usage-based charges.
• Future plans include broader automatic instrumentation, authenticated context propagation, and enhanced OpenTelemetry API support in Workers.

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📖 Source: Cloudflare Traces Turns the Proxy Layer into OpenTelemetry Spans, with New Volume-Based Pricing