API Gateway

← Previous Chapter: Part 1: CAP, PACELC & Clean Architecture | Series Hub: System Design Masterclass | Next Chapter: Part 3: Caching Strategies, Redis/Valkey & Stampede Prevention → Prerequisite: Read Part 1: CAP, PACELC & Clean Architecture Primer to understand distributed trade-offs and composite availability foundations. Answer-first: Layer 4 load balancers route packets via eBPF and Direct Server Return to achieve sub-millisecond wire speed, while Layer 7 API gateways inspect HTTP headers and enforce token bucket rate limits. Combining kernel-bypass XDP packet filtering with Go reverse proxy buffer pools sustains 100,000 requests per second with sub-5ms P99 latency bounds across distributed clusters. ...

Series Index | ← Previous Chapter: Part 3: Spatial Indexing | Next Chapter: Part 5: Route Visualization UI → Answer-first: High-concurrency routing API gateways built on Go 1.25, Kratos, and Dapr enforce defense-in-depth safeguards around downstream graph engines (GraphHopper, OSRM). Implementing Singleflight request coalescing, Sony Gobreaker circuit breaking, and flattened 1D continuous Protobuf memory arrays eliminates cascading failures, cuts duplicate queries by 99%, and guarantees sub-15ms P99 gateway SLAs. 1. Distributed Systems Reality: The Cascading Failure Hazard Writing a simple Go client using standard library http.Get() to invoke GraphHopper or OSRM endpoints is trivial. However, deploying an enterprise Geospatial API Gateway handling tens of thousands of concurrent distance calculations per second exposes severe distributed systems vulnerabilities: ...

Answer-first: API Gateways govern north-south ingress traffic crossing untrusted perimeter boundaries, executing edge authentication, rate limiting, and protocol translation. Conversely, Service Meshes manage east-west internal pod-to-pod communication, enforcing mutual TLS zero-trust identity, distributed telemetry, and traffic shifting. Rather than competing alternatives, modern architectures deploy both symbiotically, with eBPF sockops bypassing kernel TCP stacks to eliminate sidecar proxy latency. Prerequisite: In-depth knowledge of OSI Layer 4/Layer 7 networking, Kubernetes Ingress and Gateway API specifications, Envoy proxy architecture, and mutual TLS fundamentals is required for this chapter. ...

High-throughput local LLM architecture guide combining vLLM PagedAttention virtual memory, Prefill-Decode disaggregation over RoCE v2/NVLink, and a custom Go API Gateway with SHA256 prompt prefix context-affinity routing, zero-allocation SSE streaming, and 71% cost savings over SaaS APIs.

Flash Sale Architecture: Rate Limiting & Redis Answer-first: High-concurrency flash sale systems absorb millions of synchronized user requests using a 5-Tier Traffic Shedding Architecture: Cloudflare CDN edge static asset caching, Envoy API Gateway atomic Token Bucket rate limiting, Redis Cluster Lua inventory reservations with hotkey slot splitting, partitioned Kafka queue buffering, and asynchronous Go worker pools executing batch upserts into TiDB/MySQL. Prerequisite: Familiarity with Go concurrency primitives, distributed database transactions in TiDB/MySQL, and Redis Cluster caching topology at scale. ...

21-Service Go Ecommerce Microservices Diagram E-Commerce Architecture Patterns: Monolith vs Microservices Answer-first: An ecommerce microservices architecture diagram structures enterprise retail platforms into 6 bounded domains—Commerce Flow, Product & Content, Logistics, Post-Purchase, Identity & Access, and Platform Operations—powering 21 Go microservices. Orchestrated via gRPC contracts and Dapr Pub/Sub event meshes, this design delivers sub-50ms P99 latency, isolates database-per-service failures, and automates rollbacks via distributed Saga workflows. Prerequisite: Familiarity with Domain-Driven Design (DDD), gRPC service contracts, Dapr event mesh Pub/Sub, and distributed Saga patterns in Go. ...