分布式锁和消息队列:Redis和RabbitMQ的实现
在实现分布式锁和消息队列时,可以使用Redis和RabbitMQ。以下是两种场景的简化示例代码:
分布式锁的实现:
使用Redis实现分布式锁:
import redis
import uuid
def acquire_lock(conn, lock_name):
identifier = str(uuid.uuid4())
lock_key = 'lock:' + lock_name
end = time.time() + 10 # 10秒后自动释放锁
while time.time() < end:
if conn.setnx(lock_key, identifier): # 尝试获取锁
conn.expire(lock_key, 10) # 设置锁的过期时间
return identifier
time.sleep(0.001)
return False
def release_lock(conn, lock_name, identifier):
lock_key = 'lock:' + lock_name
with conn.pipeline() as pipe:
while True:
try:
pipe.watch(lock_key)
if pipe.get(lock_key) == identifier:
pipe.multi()
pipe.delete(lock_key)
pipe.execute()
return True
pipe.unwatch()
break
except redis.exceptions.WatchError:
pass
return False
消息队列的实现:
使用RabbitMQ实现消息队列:
import pika
def setup_queue(queue_name):
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.queue_declare(queue=queue_name, durable=True)
return connection, channel
def publish_message(queue_name, message):
connection, channel = setup_queue(queue_name)
channel.basic_publish(
exchange='',
routing_key=queue_name,
body=message,
properties=pika.BasicProperties(
delivery_mode=2, # 使消息持久化
),
)
print(" [x] Sent %r" % message)
connection.close()
def consume_message(queue_name, on_message_callback):
connection, channel = setup_queue(queue_name)
def callback(ch, method, properties, body):
on_message_callback(body)
channel.basic_consume(
queue=queue_name, on_message_callback=callback, auto_ack=True
)
print(" [*] Waiting for messages. To exit press CTRL+C")
channel.start_consuming()
使用这两段代码,你可以实现分布式锁和消息队列的功能。在实际应用中,你需要根据具体需求调整超时时间、重试策略、持久化设置等参数。
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