Saga Framework

Overview

The Saga Pattern Implementation in Python is a robust and flexible library that facilitates managing complex transactions in distributed systems using the Saga pattern. It ensures data consistency and reliability by handling long-running transactions through a sequence of local transactions, each with corresponding compensating actions in case of failures.

Features

• Task Management: Easily add and manage a sequence of tasks that constitute a saga.
• Compensation Mechanism: Automatically compensates completed tasks in reverse order if a failure occurs.
• Context Handling: Share contextual information across tasks seamlessly.
• Comprehensive Logging: Detailed logging of saga execution, task progress, and error handling.
• Customizable Logging: Inject custom loggers to tailor logging to your needs.
• Exception Handling: Robust error handling with custom exceptions for clear error propagation.
• Extensible Design: Modular architecture allowing for easy extension and customization.

Table of Contents

• Installation
• Usage
• Documentation
• Contributing
• License
• Contact

Installation

You can install the Saga library using pip:

pip install saga-framework

Usage Here's a simple example demonstrating how to define and execute a saga with tasks and compensations:

from saga import Saga, Task, Context
from saga.logging import SagaLogger
from saga.errors import SagaExecutionException

# Define your tasks
class CreateOrderTask(Task):
    def execute(self, context: Context):
        # Logic to create an order
        print("Order created.")

    def compensate(self, context: Context):
        # Logic to compensate order creation
        print("Order creation compensated.")

class ChargePaymentTask(Task):
    def execute(self, context: Context):
        # Logic to charge payment
        print("Payment charged.")
        # Simulate failure
        raise SagaExecutionException("Payment failed.")

    def compensate(self, context: Context):
        # Logic to refund payment
        print("Payment refunded.")

# Initialize Saga with a logger
logger = SagaLogger()
saga = Saga(logger=logger)

# Add tasks to the saga
saga.add_task(CreateOrderTask())
saga.add_task(ChargePaymentTask())

# Execute the saga
try:
    saga.execute()
except SagaExecutionException as e:
    print(f"Saga failed: {e}")