Introduction: The Challenge of Data Consistency in Distributed Systems
Maintaining data consistency in distributed system environments is a critical challenge. Transactions spanning multiple databases form a single logical unit of work, and partial completion can lead to data inconsistency. 2PC (Two-Phase Commit) is a leading protocol to address this issue. 2PC ensures that either all participating nodes successfully complete the transaction, or no changes are made, preserving the ACID properties of the data.
Core Concepts and Principles
2PC is a protocol that guarantees the ACID properties (Atomicity, Consistency, Isolation, Durability) of distributed transactions. It consists of a Coordinator and Participants and proceeds in two phases: Prepare Phase and Commit Phase.
Prepare Phase
The Coordinator sends a message to all Participants to prepare the transaction. Each Participant executes the transaction, logs the results, and sends a Ready (Vote-Commit) or Failure (Vote-Abort) response to the Coordinator.
Commit Phase
If the Coordinator receives Ready responses from all Participants, it sends a Commit message, instructing them to commit the transaction. If it receives even one Failure response, it sends a Rollback message, instructing them to roll back all changes. Participants then commit or roll back the transaction as instructed by the Coordinator.
Latest Trends and Changes
Recent global IT trends such as AI, Cloud Computing, and enhanced Cybersecurity are highlighting the importance of technologies that ensure data consistency in distributed system environments. According to PwC's 2026 Semiconductor Industry Trends Outlook, the proliferation of AI is expected to rapidly expand the server and automotive semiconductor markets, which may increase the complexity of distributed systems and exacerbate the difficulty of maintaining data consistency. Reports from major institutions like Gartner and IDC suggest that the importance of hardware and cloud specifically designed for AI will increase further by 2026.
Practical Implementation Strategies
2PC is widely used in distributed systems where data consistency is critical, such as banking and reservation systems. For example, in a banking system, an account transfer transaction spans multiple databases (account information, transaction history, etc.). 2PC ensures that the transfer operation is either fully completed, or all changes are rolled back, preventing inconsistencies in account balances. In MSA environments, transaction patterns such as the SAGA pattern, 2PC, and CQRS are used to maintain data consistency.
Expert Recommendations
💡 Technical Insight
Cautions When Adopting the Technology: 2PC can be complex to implement and may cause performance degradation. In particular, a failure in the Coordinator can cause a Blocking problem, halting the entire system. Therefore, the decision to apply 2PC should be made after carefully considering the system's requirements and constraints. Considering alternative technologies such as the SAGA pattern is also a good approach.
Outlook for the Next 3-5 Years: The enforcement of the AI Framework Act (scheduled for January 22, 2026) may impose obligations on high-impact AI and generative AI, which could affect data management and transaction processing methods. The importance of technologies that ensure data consistency in cloud environments is expected to increase further.
Conclusion
2PC is an important protocol for ensuring data consistency in distributed transaction environments. However, it also has drawbacks such as implementation complexity, performance degradation, and Blocking problems. Therefore, an appropriate transaction processing method should be selected considering the characteristics and requirements of the system. With the advancement of technologies such as AI and Cloud Computing, the importance of maintaining data consistency will further increase, and various technical approaches for this are expected to be researched.