Shopify将库存预留系统从Redis迁移至MySQL，成功支撑了2025年黑五购物节的高并发需求[1]。该时期平台达到每分钟510万美元的销售峰值，较上年增长11%[1]。
迁移方案充分利用了MySQL 8的SKIP LOCKED特性，采用一行一个库存单位的设计架构[1]。每个商品与位置的组合维护1000行的有限库存池，在突发流量吸收能力和查询性能间取得平衡[1]。通过改进复合主键设计，Shopify将每次预留操作所需的锁数从2个降低至1个[1]。同时采用READ COMMITTED隔离级别来避免间隙锁对补充操作的阻塞[1]。
在优化过程中，Shopify团队发现真正的瓶颈并非来自查询性能，而是数据库连接池被其他业务流程长期占用[1]。通过在ProxySQL层使用SQL注释标签追踪连接时间，问题得以定位[1]。随后的数据库清理和配置优化移除了50%的读操作和33%的事务，实现了系统容量扩展[1]。迁移期间，Shopify采用影子模式同时运行Redis和MySQL进行验证，逐步灰度切换以确保稳定性[1]。
Shopify transitioned its inventory reservation system from Redis to MySQL, achieving significant performance gains during peak shopping periods.[1] The e-commerce platform reached sales of $5.1 million per minute during Black Friday 2025, representing an 11% increase compared to the previous year.[1]
The migration leveraged MySQL 8's SKIP LOCKED feature, enabling a one-row-per-inventory-unit design that eliminated row-level lock contention.[1] Each product-location combination maintained a limited pool of 1,000 rows to balance burst absorption capacity with query performance.[1] Engineers optimized the composite primary key design to reduce locks per reservation from two to one, and adopted READ COMMITTED isolation level to prevent gap locks from blocking replenishment operations.[1]
The implementation process revealed that the primary bottleneck was not query performance but rather database connection pool exhaustion caused by other business processes.[1] Using SQL comment tags in ProxySQL to track connection times, the team identified long-held connections that were starving the inventory system.[1] Database cleanup and configuration improvements eliminated 50% of read operations and 33% of transactions, enabling successful capacity expansion.[1] Shopify employed a shadow mode strategy with dual-write operations, running both Redis and MySQL in parallel to validate the system before gradually rolling out the MySQL-only version.[1]