Ensuring Atomicity in Distributed Transactions for Microservices

In microservices architectures, maintaining data consistency across multiple, independently functioning services is a fundamental challenge. Unlike monolithic applications, where a single, centralized database allows for ACID (Atomicity, Consistency, Isolation, Durability) transactions, microservices often require each service to have its own database. This decentralized approach introduces complications for distributed transactions, where each service must complete its part of a transaction for the entire operation to be considered successful.

For example, in an e-commerce system, processing an order involves multiple services, each with its own responsibilities and databases:

• Product Catalog Service verifies product availability.
• Cart Service adds items to the user’s cart.
• Payment Service processes payments.
• Order Service completes the order and updates inventory.

In such a distributed environment, if any of these services fails during the transaction (e.g., the Payment Service fails after deducting funds but before completing the order), inconsistencies arise, leaving the transaction incomplete and resulting in poor user experience and potentially significant data issues.