Distributed Transactions: Two-Phase Commit Protocol
Issue #62: System Design Interview Roadmap
🎯 Today's Deep Dive: Master the Two-Phase Commit Protocol with production-grade insights, real failure patterns, and hands-on implementation. Plus: complete demo system you can run locally.
The Million-Dollar Race Condition
Picture this: You're building the payment system for a global e-commerce platform. A customer in Tokyo clicks "Buy Now" for a $2,000 laptop. In that split second, your system needs to charge their credit card, update inventory, create a shipping order, and send a confirmation email. But here's the catch—these operations happen across four different services, running on different servers, in different data centers.
What happens if the payment succeeds but the inventory update fails? You've charged the customer but can't fulfill the order. What if the shipping service crashes after creating the order but before the email service confirms? You're left with phantom shipments and confused customers.
💡 The Core Challenge: This isn't a hypothetical scenario—it's the daily reality for any distributed system handling critical transactions. Welcome to the world of distributed transactions, where the Two-Phase Commit Protocol (2PC) serves as both a lifeline and a potential bottleneck.