Day 9 of #DistributedDilemmas: Distributed transactions are a myth at scale

Two-phase commit falls apart under network partitions. Design for compensation, not for distributed atomicity.

2PC’s (2 Phase Commit) Fundamental Limitations:
When coordinator-participant communication fails after prepare phase, 2PC enters indefinite blocking where participants can’t safely commit/abort without coordinator. This creates the “cask effect” where one failure paralyzes the whole system. https://cs.stackexchange.com/questions/76192/why-is-two-phase-commit-2pc-blocking

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Alibaba__Cloud ‘s distributed transaction solution uses Saga(Compensation Pattern) to handle cross-service payments:

1. Order service creates order record
2. Payment service deducts funds
3. Notification service sends receipt

If any step fails:

1. Payment Service → Reverse deduction
2. Order Service → Mark order failed
3. Notification → Cancel pending emails

https://www.alibabacloud.com/blog/an-in-depth-analysis-of-distributed-transaction-solutions_597232

Day 9 on X ↗