Context and Problem
Distributed systems often lack traditional ACID transactions, requiring alternative consistency mechanisms:
- Operations across multiple services may fail partially
- Rollback mechanisms are needed when failures occur
- Data inconsistency can arise due to partial updates
Solution
Compensating transactions roll back failed operations through explicit undo actions:
- Define compensating actions for each business operation
- If a failure occurs, trigger compensating actions to revert changes
- Use event-driven workflows to manage rollback processes
Benefits
- Data Consistency
- Ensures system state remains valid even after failures
- Fault Tolerance
- Allows systems to recover from partial failures
- Decoupled Transactions
- Works without requiring distributed ACID transactions
Trade-offs
- Complexity
- Requires defining and managing compensating actions
- Delay in Rollbacks
- Rollbacks may not be instant, leading to temporary inconsistencies
- Business Logic Overhead
- Application logic must support failure handling mechanisms
Issues and Considerations
- Orchestration Complexity
- Managing compensating actions across multiple services
- Idempotency
- Ensuring compensating actions do not introduce side effects
- Monitoring
- Detecting and handling rollback failures effectively
When to Use This Pattern
- Your system spans multiple independent services
- Traditional ACID transactions are not feasible
- You need a mechanism to handle partial failures gracefully