Observability

Snakeway provides built‑in observability primitives intended for production deployments of a high‑performance edge proxy. The observability subsystem is designed to expose operational signals while keeping overhead predictable and minimal in the request hot path.

The system focuses on three goals:

• structured logs suitable for machine ingestion
• distributed tracing using OpenTelemetry
• a separation between control plane instrumentation and data plane execution

The implementation favors explicit initialization and deterministic startup ordering to avoid hidden runtime behavior.

Summary

The observability subsystem in Snakeway is intentionally minimal in the request hot path while still exposing the signals required to operate the proxy in production environments. Control plane components manage exporter lifecycles and asynchronous telemetry tasks, while data plane code emits structured events and tracing spans with minimal overhead.

Design Principles

Structured Logging

Snakeway uses the tracing ecosystem for structured logging. Logs are emitted as JSON events with flattened fields to make ingestion by log aggregation systems straightforward.

Logs are intended to represent operational state transitions such as:

• startup and shutdown events
• configuration reload activity
• certificate automation lifecycle
• device pipeline execution outcomes
• upstream proxy interactions

The logging system supports two output modes:

• standard output for container environments
• rolling file logs when SNAKEWAY_LOG_DIR is configured

File logging uses a non‑blocking writer to ensure the request path is not affected by disk IO.

Distributed Tracing

Distributed tracing is implemented through OpenTelemetry and the tracing-opentelemetry integration layer.

The OpenTelemetry pipeline is configured through the Snakeway runtime configuration and includes:

• OTLP exporter endpoint
• service metadata such as service.name and service.version
• sampling strategy

Tracing spans originate from the tracing instrumentation already used for structured logging. The subscriber bridges these spans into the OpenTelemetry exporter.

The exporter operates using a batch processor that runs on the control plane runtime. This avoids blocking request processing while traces are exported.

Runtime Metadata

Snakeway attaches resource metadata to every exported trace. The metadata follows OpenTelemetry semantic conventions and includes service attributes such as:

• service name
• service version
• instance identifier derived from the system hostname

This information allows telemetry backends to distinguish between instances in multi‑node deployments.

Sampling

The current implementation supports a parent‑based sampling model. The sampling decision propagates across nested spans so that trace hierarchies remain coherent.

Additional sampling strategies may be introduced later, but the default configuration ensures that traces remain complete once a root span has been sampled.

Request Instrumentation

Request processing is instrumented through spans created within the Pingora gateway implementation. A typical trace hierarchy represents the full request lifecycle:

• request span
• routing span
• device pipeline spans
• upstream proxy span

The device pipeline model allows individual devices to emit spans describing enrichment, filtering, or policy evaluation performed on the request.

Shutdown Behavior

The OpenTelemetry tracer provider is stored globally so that the exporter can flush pending spans during shutdown. This ensures that traces generated during the final moments of process execution are not lost.

Graceful shutdown hooks trigger exporter shutdown before the process exits.