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Redis Python客户端打开了许多连接

redis-py redis python

2

Muthu · 技术社区 · 7 年前

我正在使用以下代码连接Redis服务器。我看到大量连接处于TIME\u WAIT状态。可能有什么问题?

root@ubuntu:~$ netstat | grep :6479 | grep TIME_WAIT |wc -l
9061
root@ubuntu:~$ netstat | grep :6479 | grep ESTABLISHED |wc -l
7

我曾想过使用以下代码在Redis server上完成操作后关闭连接。但我发现了这个错误。

@staticmethod
def disconnectRedisConnection(r_server):
    if r_server is not None and r_server:
        r_server.connection.disconnect()

r_server.connection.disconnect()
AttributeError: 'Redis' object has no attribute 'connection'

对于使用Redis完成操作后等待连接/关闭连接的巨大时间有何想法?

import threading
from time import sleep
import time, datetime
import traceback
import CACHE_CONST
import json
import os

import MySQLdb
import redis

# Static methods to interact with the Redis cache server
class CacheUtil(object):

    # Log Errors
    @staticmethod
    def log_message(msg):
        log_file = None
        log_file = open (os.path.abspath(CACHE_CONST.REDIS_LOG_FILE), "a")
        print(msg)
        if (log_file):
            message = time.strftime("%d-%m-%Y %H:%M:%S")    
            message += " :: " + str(msg)
            log_file.write(message + "\n")

    @staticmethod
    def saveToCache(hashName, hashValue):
        r_server = CacheUtil.getRedisConnection()
        r_server.hmset(hashName, hashValue)
        CacheUtil.disconnectRedisConnection(r_server)

    @staticmethod
    def getTrackerDetailsByID(trackerId):
        trackerDetail = None
        r_server = None
        hashName = "tDetails:" + str(trackerId)
        try:
            if trackerId is not None:
                print("getTrackerDetailsByID ")
                r_server = CacheUtil.getRedisConnection()
                trackerDetail = r_server.hgetall(hashName)
            else:
                CacheUtil.log_message("getDetailsByID failed with empty trackerId ")
        except:
            CacheUtil.log_message("getDetailsByID failed, ll fetch from DB " + str(traceback.format_exc()))
        finally:
            CacheUtil.disconnectRedisConnection(r_server)
        return trackerDetail

    @staticmethod
    def getRedisConnection():
        print("Get Redis Connection on Util ")
        r_server = redis.Redis(host=CACHE_CONST.REDIS_SERVER_URL, port=CACHE_CONST.REDIS_SERVER_PORT, db=0, password=CACHE_CONST.REDIS_PASS_PHRASE, socket_connect_timeout=2, socket_timeout=2)
        return r_server;

    @staticmethod
    def disconnectRedisConnection(r_server):
        if r_server is not None and r_server:
            r_server.connection.disconnect()

1 回复 | 直到 7 年前

1

4

GuangshengZuo 7 年前

实际上,当你打电话给 redis.Redis()

每次发送redis之类的命令时。set()或其他,它将从其连接池中检索连接,并使用此连接发送此命令并等待回复。当请求完成后,它将连接放回连接池以供重用。因此,您不需要自己管理连接。看看这个 https://github.com/andymccurdy/redis-py 了解更多信息。

import threading
from time import sleep
import time, datetime
import traceback
import CACHE_CONST
import json
import os

import MySQLdb
import redis
r_server = redis.Redis(host=CACHE_CONST.REDIS_SERVER_URL, port=CACHE_CONST.REDIS_SERVER_PORT, db=0, password=CACHE_CONST.REDIS_PASS_PHRASE, socket_connect_timeout=2, socket_timeout=2)

# Static methods to interact with the Redis cache server
class CacheUtil(object):

    # Log Errors
    @staticmethod
    def log_message(msg):
        log_file = None
        log_file = open (os.path.abspath(CACHE_CONST.REDIS_LOG_FILE), "a")
        print(msg)
        if (log_file):
            message = time.strftime("%d-%m-%Y %H:%M:%S")    
            message += " :: " + str(msg)
            log_file.write(message + "\n")

    @staticmethod
    def saveToCache(hashName, hashValue):
        r_server.hmset(hashName, hashValue)

    @staticmethod
    def getTrackerDetailsByID(trackerId):
        hashName = "tDetails:" + str(trackerId)
        try:
            if trackerId is not None:
                print("getTrackerDetailsByID ")
                trackerDetail = r_server.hgetall(hashName)
            else:
                CacheUtil.log_message("getDetailsByID failed with empty trackerId ")
        except:
            CacheUtil.log_message("getDetailsByID failed, ll fetch from DB " + str(traceback.format_exc()))
        return trackerDetail

更新

    # COMMAND EXECUTION AND PROTOCOL PARSING
def execute_command(self, *args, **options):
    "Execute a command and return a parsed response"
    pool = self.connection_pool
    command_name = args[0]
    connection = pool.get_connection(command_name, **options)
    try:
        connection.send_command(*args)
        return self.parse_response(connection, command_name, **options)
    except (ConnectionError, TimeoutError) as e:
        connection.disconnect()
        if not connection.retry_on_timeout and isinstance(e, TimeoutError):
            raise
        connection.send_command(*args)
        return self.parse_response(connection, command_name, **options)
    finally:
        pool.release(connection)

对于使用Redis完成操作后等待连接/关闭连接的时间过长有何想法

这是关于TCP连接终止过程的图像。当客户端(启动器)为服务器(接收器)FIN发送ACK时,它进入Time\u WAIT状态。

最后一次确认时,该连接必须在TIME_WAIT状态下保持MSL的两倍。这让TCP (它们不使用序列号,也不由TCP重新传输),但因为另一方将重新传输其FIN(它确实消耗序列号)。实际上,TCP总是会重新传输直到收到最终确认。

还有一篇关于 the purpose about TIME_WAIT