#Algorithms
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A Comprehensive Guide to Caching: From CPU Architectures to Modern Distributed Systems
10 min read • Published onCaching is more than just a performance optimization technique—it’s a fundamental design pattern that has shaped the evolution of computing from its earliest days. From the hardware-level innovations that solved the processor-memory performance gap to the sophisticated distributed systems that power the modern internet, caching represents a recurring solution to the universal problem of latency.This comprehensive guide explores caching through multiple lenses: its architectural history, the mathematical principles that govern its effectiveness, the algorithms that determine its behavior, and the practical implementations that make it work at scale. Whether you’re designing a new system or optimizing an existing one, understanding these concepts is essential for building performant, scalable applications.
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LRU Cache: From Classic Implementation to Modern Alternatives
16 min read • Published onCaching is the unsung hero of high-performance applications. When implemented correctly, it can dramatically reduce latency, ease database load, and create a snappy, responsive user experience. Statistics show that even a one-second delay can cut conversions by 7%. For decades, the go-to solution for developers has been the Least Recently Used (LRU) cache, a simple yet effective strategy for keeping frequently used data close at hand.But what happens when this trusty tool fails? While LRU is a powerful default, it has a critical flaw that can cripple performance under common workloads. This vulnerability has spurred decades of research, leading to a new generation of smarter, more resilient caching algorithms that build upon LRU’s foundation.This guide will take you on a journey from the classic LRU cache implementation to understanding its limitations and exploring modern alternatives. We’ll dive deep into LRU’s inner workings, examine when it fails, and discover how advanced algorithms like LRU-K, 2Q, and ARC address these shortcomings.