Scheduler Pattern in Design Patterns

1. Introduction

The Scheduler Pattern is a design pattern that is used to manage the execution of tasks or jobs based on a specific schedule or time. This pattern is essential in scenarios where tasks need to be executed at predetermined times or intervals.

2. Key Concepts

3. Implementation

Here is a simple implementation of the Scheduler pattern in Python:

import time
import threading

class Task:
    def __init__(self, name):
        self.name = name

    def execute(self):
        print(f'Task {self.name} is being executed.')

class Scheduler:
    def __init__(self):
        self.tasks = []

    def add_task(self, task, delay):
        self.tasks.append((task, delay))
        threading.Timer(delay, task.execute).start()

scheduler = Scheduler()
scheduler.add_task(Task('Task 1'), 5)  # Execute after 5 seconds
scheduler.add_task(Task('Task 2'), 10) # Execute after 10 seconds
            

In this example, tasks are scheduled to run after a specified delay using threading.

4. Best Practices

• Use a robust scheduling library if available.
• Implement retries for failed tasks.
• Monitor and log scheduled tasks for debugging.
• Consider using a message queue for task distribution.

5. FAQ