分布式锁实现方案--redis、zookeeper、mysql

这个问题涉及到了分布式锁的几种实现方式，以下是简单的实现方法和示例代码：

1. 使用Redis实现分布式锁：

import redis
import time
import uuid
 
def acquire_lock(conn, lock_name):
    identifier = str(uuid.uuid4())
    end = time.time() + 10  # 10秒超时
    lock_name = 'lock:' + lock_name
 
    while time.time() < end:
        if conn.setnx(lock_name, identifier):
            return identifier
        time.sleep(0.001)
 
    return False
 
def release_lock(conn, lock_name, identifier):
    lock_name = 'lock:' + lock_name
    pipe = conn.pipeline(True)
    while True:
        try:
            pipe.watch(lock_name)
            if pipe.get(lock_name) == identifier:
                pipe.multi()
                pipe.delete(lock_name)
                pipe.execute()
                return True
            pipe.unwatch()
            break
        except redis.exceptions.WatchError:
            pass
    return False

2. 使用Zookeeper实现分布式锁：

import zookeeper
 
zk = zookeeper.init("localhost:2181")
 
def acquire_lock(lock_path):
    lock_path = "/" + lock_path
    zk.exists(lock_path, True, None)
    lock_node = lock_path + "/lock-" + str(zookeeper.get_cnxid())
    zk.create(lock_node, "", [zookeeper.EPHEMERAL], True)
    children = zk.get_children(lock_path, True)
    lock_nodes = sorted(child for child in children 
                        if child.startswith('lock-'))
    if lock_node == lock_path + "/" + lock_nodes[0]:
        return True
    for lock_node in lock_nodes:
        if lock_node < our_lock_node:
            zk.exists("/" + lock_path + "/" + lock_node, True, None)
 
def release_lock(lock_path):
    zk.stop()

3. 使用MySQL实现分布式锁：

import MySQLdb
import time
 
def acquire_lock(cursor, lock_name):
    end_time = time.time() + 10
    while time.time() < end_time:
        try:
            cursor.execute("SELECT GET_LOCK(%s, 1)", (lock_name,))
            if cursor.fetchone()[0] == 1:
                return True
        except MySQLdb.OperationalError:
            pass
        time.sleep(0.001)
    return False
 
def release_lock(cursor, lock_name):
    cursor.execute("SELECT RELEASE_LOCK(%s)", (lock_name,))

以上代码仅为示例，实际应用时需要考虑更多的异常处理和性能优化。