478254400a
- Updated service template structure in `ARCHITECTURE.md` and `README.md` for clarity and usability. - Enhanced bilingual documentation across skills, increasing the number of available skills from 15 to 25. - Added new sections on event-driven architecture, inter-service communication, and performance optimization. - Improved formatting and removed outdated references to streamline the documentation experience.
97 lines
2.8 KiB
Markdown
97 lines
2.8 KiB
Markdown
---
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name: data-consistency-patterns
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description: Data consistency patterns for distributed microservices including Saga patterns, distributed transactions, eventual consistency, compensation, and idempotency. Use when handling distributed transactions, implementing eventual consistency, or managing data synchronization across services.
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---
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# Data Consistency Patterns
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## When to Use This Skill
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Use this skill when:
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- Implementing distributed transactions across multiple services
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- Handling eventual consistency in microservices
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- Implementing Saga patterns for distributed workflows
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- Designing compensation strategies for failed transactions
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- Implementing idempotent operations
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- Managing data synchronization across services
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- Handling conflict resolution
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## Core Concepts
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### ACID vs BASE
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**ACID (Traditional):** Atomicity, Consistency, Isolation, Durability
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**BASE (Distributed):** Basic Availability, Soft state, Eventual consistency
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### Consistency Models
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- **Strong Consistency**: All nodes see same data at same time
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- **Eventual Consistency**: System becomes consistent over time
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- **Weak Consistency**: No guarantees about when consistency occurs
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## Key Patterns
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### Saga Orchestrator Pattern
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```typescript
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// Centralized orchestrator coordinates steps
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const saga = new SagaOrchestrator();
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await saga.execute({
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sagaId: 'saga_123',
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steps: [
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{ name: 'create-order', execute: createOrder, compensate: cancelOrder },
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{ name: 'reserve-inventory', execute: reserveInventory, compensate: releaseInventory },
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{ name: 'process-payment', execute: chargePayment, compensate: refundPayment },
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],
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data: {},
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status: 'pending',
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});
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```
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### Saga Choreography Pattern
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```typescript
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// Services react to events
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eventConsumer.on('order.created', async (event) => {
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await inventoryService.reserve(event.data.items);
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await eventPublisher.publish('inventory.reserved', {...});
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});
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```
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### Idempotency
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```typescript
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// Execute operation with idempotency check
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await idempotencyHandler.execute(
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idempotencyKey,
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async () => await userService.create(data)
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);
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```
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### Optimistic Locking
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```typescript
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// Update with version check
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await optimisticLockService.updateWithLock(
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repository,
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id,
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(current) => ({ ...current, name: newName })
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);
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```
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## Best Practices
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1. **Design Compensations**: Every step needs compensation
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2. **Idempotent Steps**: Make steps idempotent for retries
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3. **Conflict Resolution**: Define resolution strategies
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4. **Monitoring**: Track saga execution and consistency lag
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5. **Read Models**: Use separate read models for queries (CQRS)
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## Resources
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- [Saga Pattern](https://microservices.io/patterns/data/saga.html)
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- [Event-Driven Architecture](./event-driven-architecture.md)
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- [Error Handling Patterns](./error-handling-patterns.md)
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- Skill Source: `.cursor/skills/data-consistency-patterns/SKILL.md`
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