Load-Balancing

Table of Contents Introduction The Problem Space: Why Simple Hashing Fails at Scale Fundamentals of Consistent Hashing 3.1 The Ring Metaphor 3.2 Virtual Nodes (VNodes) 3.3 Hash Functions and Their Role Designing a Consistent Hashing Library from Scratch 4.1 Choosing a Language: Go Example 4.2 Core Data Structures 4.3 Adding & Removing Nodes 4.4 Key Lookup Logic 4.5 Putting It All Together Integrating Consistent Hashing into Real Systems 5.1 Distributed Caching (e.g., Memcached, Redis Cluster) 5.2 NoSQL Databases (Cassandra, DynamoDB) 5.3 Content Delivery Networks (CDNs) and Edge Routing Handling Node Dynamics: Scaling Up & Down Gracefully 6.1 Data Migration Strategies 6.2 Replication & Fault Tolerance Advanced Variants and Optimizations 7.1 Rendezvous (Highest Random Weight) Hashing 7.2 Weighted Nodes & Capacity‑Based Distribution 7.3 Multi‑Probe & Jump Consistent Hashing Performance Considerations & Benchmarks Best Practices, Common Pitfalls, and Gotchas 10 Real‑World Case Studies 10.1 Amazon Dynamo’s Ring Architecture 10.2 Apache Cassandra’s Token Allocation 10.3 Netflix’s EVCache 11 Conclusion 12 Resources Introduction Scalable distributed systems are the backbone of modern web services, from massive key‑value stores to globally replicated caches and content‑delivery networks. One of the most recurring challenges in these environments is load balancing—distributing client requests or data partitions evenly across a dynamic set of nodes while minimizing data movement when the cluster topology changes. ...

Introduction In modern web architecture, the term reverse proxy appears in almost every conversation about scalability, security, and reliability. While a forward proxy sits between clients and the internet, a reverse proxy sits in front of one or more servers, acting as an intermediary for inbound traffic. It receives client requests, applies a set of policies, and forwards those requests to the appropriate backend service. The response then travels back through the same proxy, allowing the proxy to perform transformations, caching, authentication, and more before delivering the final payload to the client. ...

Introduction In today’s cloud‑first, API‑driven world, securing data in transit is non‑negotiable. Transport Layer Security (TLS)—the modern successor to Secure Sockets Layer (SSL)—provides confidentiality, integrity, and authentication for network traffic. However, encrypting every packet end‑to‑end can impose considerable computational overhead on application servers, especially when they must handle thousands of concurrent connections. Enter SSL termination (often called TLS termination). This architectural pattern offloads the heavy lifting of TLS handshakes and encryption/decryption to a dedicated component—typically a load balancer, reverse proxy, or edge gateway—allowing backend services to operate on plain HTTP. By terminating TLS at a strategic point in the network, teams gain performance benefits, simplify certificate management, and enable advanced routing features, all while preserving end‑user security expectations. ...

Introduction vLLM has quickly become one of the most popular inference engines for serving large language models efficiently, thanks to its paged attention and strong OpenAI-compatible API. But as soon as you move beyond a single GPU or a single model server, you run into familiar infrastructure questions: How do I distribute traffic across multiple vLLM servers? How do I handle failures and keep latency predictable? How do I roll out new model versions without breaking clients? This is where the vLLM Router comes in. ...

Introduction HAProxy is the de facto open-source load balancer and reverse proxy for high-traffic websites, APIs, and microservices. It’s fast, battle-tested, extremely configurable, and equally at home terminating TLS, routing based on headers or paths, defending against abuse, or load balancing TCP streams. This zero-to-hero guide takes you from first principles to production-ready configurations. We’ll cover installation, core concepts, practical configuration patterns, TLS, health checks, observability, advanced features like ACLs and stick tables, and safe reloads—with copy-and-pasteable examples. ...