RPC

Design

• Context: Every RPC entry point or client call MUST accept context.Context as the first argument.
• Tracing: All RPCs MUST be instrumented with OpenTelemetry.
  • Server: Extract context, start span.
  • Client: Inject context, start span.

Resilience

Timeouts

Set a deadline on every outgoing request.

ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
defer cancel()

Scenario	Timeout
Inter-service (same datacenter)	2s
External API	5-10s
User-facing	1s
Background jobs	30-60s

Retries

Use exponential backoff with jitter for transient failures.

• gRPC: Use grpc_retry middleware.
• HTTP: Use go-retryablehttp.