saga-orchestration

# Saga Orchestration

Patterns for managing distributed transactions and long-running business processes.

## When to Use This Skill

- Coordinating multi-service transactions
- Implementing compensating transactions
- Managing long-running business workflows
- Handling failures in distributed systems
- Building order fulfillment processes
- Implementing approval workflows

## Core Concepts

### 1. Saga Types

```
Choreography                    Orchestration
┌─────┐  ┌─────┐  ┌─────┐     ┌─────────────┐
│Svc A│─►│Svc B│─►│Svc C│     │ Orchestrator│
└─────┘  └─────┘  └─────┘     └──────┬──────┘
   │        │        │               │
   ▼        ▼        ▼         ┌─────┼─────┐
 Event    Event    Event       ▼     ▼     ▼
                            ┌────┐┌────┐┌────┐
                            │Svc1││Svc2││Svc3│
                            └────┘└────┘└────┘
```

### 2. Saga Execution States

| State | Description |
|-------|-------------|
| **Started** | Saga initiated |
| **Pending** | Waiting for step completion |
| **Compensating** | Rolling back due to failure |
| **Completed** | All steps succeeded |
| **Failed** | Saga failed after compensation |

## Templates

### Template 1: Saga Orchestrator Base

```python
from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from enum import Enum
from typing import List, Dict, Any, Optional
from datetime import datetime
import uuid

class SagaState(Enum):
    STARTED = "started"
    PENDING = "pending"
    COMPENSATING = "compensating"
    COMPLETED = "completed"
    FAILED = "failed"


@dataclass
class SagaStep:
    name: str
    action: str
    compensation: str
    status: str = "pending"
    result: Optional[Dict] = None
    error: Optional[str] = None
    executed_at: Optional[datetime] = None
    compensated_at: Optional[datetime] = None


@dataclass
class Saga:
    saga_id: str
    saga_type: str
    state: SagaState
    data: Dict[str, Any]
    steps: List[SagaStep]
    current_step: int =