Singleflight

Prerequisite: Part 3 of the System Design Masterclass. Read Part 2: Load Balancing L4/L7 to understand the traffic layer before diving into the caching tier. Answer-first: Effective caching strategy selection hinges on the acceptable consistency window and the read/write access pattern of the workload. Write-Through suits financial records; Write-Behind suits analytics and event counters; Cache-Aside is the default for read-heavy API responses. How Does Cache Stampede Happen? Answer-first: Cache Stampede (thundering herd) occurs when a popular cached key expires and multiple concurrent goroutines simultaneously detect a cache miss — then all query the database simultaneously. The burst of duplicate DB queries can exceed connection pool capacity and cause cascading failure. ...

← Previous | Series hub | Next → Chapter 2: The 3 Deadliest Cache Vulnerabilities Caching is the ultimate shield for databases in distributed systems. However, poorly implemented caches can become the exact reason your system crashes. In this chapter, we dissect three classic caching phenomenons and how to defend against them using Golang. 1. Cache Penetration Answer-first: Cache penetration occurs when attackers query non-existent IDs, bypassing the cache entirely. Defend against it by caching NULL values or utilizing Bloom Filters at the memory level. ...