Redis：构建高可扩展性系统的利器

sentinel monitor mymaster 127.0.0.1 6379 2
sentinel down-after-milliseconds mymaster 5000
sentinel failover-timeout mymaster 60000

# 使用redis-py实现哨兵模式
import redis

sentinel = redis.RedisSentinel(
    [('127.0.0.1', 26379)],
    Socket_timeout=0.1,
)

redis_master = sentinel.master_for('mymaster', socket_timeout=0.1)
redis_slave = sentinel.slave_for('mymaster', socket_timeout=0.1)

redis_master.set('key', 'value')
print(redis_slave.get('key'))

import redis

class RedisLock(object):
    def __init__(self, name, acquire_timeout=10, expire_time=60):
        self.redis = redis.Redis()
        self.name = 'redis_lock_key_{}'.fORMat(name)
        self.acquire_timeout = acquire_timeout
        self.expire_time = expire_time

    def acquire_lock(self):
        start_time = time.time()
        while True:
            end_time = time.time()
            if self.redis.setnx(self.name, 1):
                self.redis.expire(self.name, self.expire_time)
                return True
            elif end_time - start_time > self.acquire_timeout:
                return False
            time.sleep(0.1)

    def release_lock(self):
        self.redis.delete(self.name)
        
redis_lock = RedisLock('test')
if redis_lock.acquire_lock():
    try:
        # 操作共享资源
        pass
    finally:
        redis_lock.release_lock()

import redis
import threading

def subscribe_channel(redis, channel):
    pub_sub = redis.pubsub()
    pub_sub.subscribe(channel)
    for message in pub_sub.listen():
        print(message)

redis_sub = redis.StrictRedis(decode_responses=True)
redis_pub = redis.StrictRedis(decode_responses=True)

redis_thread = threading.Thread(target=subscribe_channel, args=(redis_sub, 'test_channel'))
redis_thread.start()

redis_pub.publish('test_channel', 'Hello, Redis!')

import redis

redis_client = redis.Redis()

add_script = redis_client.reGISter_script("""
    local current_value = redis.call('get', KEYS[1])
    current_value = tonumber(current_value) or 0
    current_value = current_value + tonumber(ARGV[1])
    redis.call('set', KEYS[1], current_value)
    return current_value
""")

add_script(keys=['test_lua_key'], args=[1])