#Lab: Design Patterns Implementation

1import time
2
3class CircuitBreaker:
4    def __init__(self, failure_threshold=5, recovery_timeout=30):
5        self.failure_count = 0
6        self.failure_threshold = failure_threshold
7        self.recovery_timeout = recovery_timeout
8        self.last_failure_time = None
9        self.state = "CLOSED"
10    
11    def call(self, func, *args, **kwargs):
12        if self.state == "OPEN":
13            if time.time() - self.last_failure_time > self.recovery_timeout:
14                self.state = "HALF_OPEN"
15            else:
16                raise Exception("Circuit is OPEN")
17        
18        try:
19            result = func(*args, **kwargs)
20            self.failure_count = 0
21            self.state = "CLOSED"
22            return result
23        except Exception as e:
24            self.failure_count += 1
25            self.last_failure_time = time.time()
26            if self.failure_count >= self.failure_threshold:
27                self.state = "OPEN"
28            raise e

1import time
2import random
3
4def retry_with_backoff(func, max_retries=3, base_delay=1):
5    for attempt in range(max_retries):
6        try:
7            return func()
8        except Exception as e:
9            if attempt == max_retries - 1:
10                raise
11            delay = base_delay * (2 ** attempt) + random.uniform(0, 1)
12            time.sleep(delay)

1from flask import Flask, jsonify
2
3app = Flask(__name__)
4
5@app.route('/health')
6def health():
7    return jsonify({
8        "status": "healthy",
9        "checks": {
10            "database": check_database(),
11            "cache": check_cache()
12        }
13    })