MQTT Paho Python客户端订阅服务器，如何永远订阅？

尝试在不断开连接的情况下简单订阅Mosquitto代理，以从发布特定主题数据的设备获取所有消息，将它们保存在BD中，并将它们发布到执行“staff”操作的php中

这是我的订阅

import paho.mqtt.client as mqtt
from mqtt_myapp import *

topic="topic/#"                 # MQTT broker topic
myclient="my-paho-client"           # MQTT broker My Client
user="user"                     # MQTT broker user
pw="pass"                       # MQTT broker password
host="localhost"                # MQTT broker host
port=1883                       # MQTT broker port
value="123"                     # somethin i need for myapp

def on_connect(mqttc, userdata, rc):
    print('connected...rc=' + str(rc))
    mqttc.subscribe(topic, qos=0)

def on_disconnect(mqttc, userdata, rc):
    print('disconnected...rc=' + str(rc))

def on_message(mqttc, userdata, msg):
    print('message received...')
    print('topic: ' + msg.topic + ', qos: ' + 
          str(msg.qos) + ', message: ' + str(msg.payload))
    save_to_db(msg)
    post_data(msg.payload,value)

def on_subscribe(mqttc, userdata, mid, granted_qos):
    print('subscribed (qos=' + str(granted_qos) + ')')

def on_unsubscribe(mqttc, userdata, mid, granted_qos):
    print('unsubscribed (qos=' + str(granted_qos) + ')')

mqttc = mqtt.Client(myclient)
mqttc.on_connect = on_connect
mqttc.on_disconnect = on_disconnect
mqttc.on_message = on_message
mqttc.on_subscribe = on_subscribe
mqttc.on_unsubscribe = on_unsubscribe
mqttc.username_pw_set(user,pw)
mqttc.connect(host, port, 60)
mqttc.loop_forever()

这是我的mqtt_myapp.py：

import MySQLdb
import requests # pip install requests

url = "mydomain/data_from_broker.php"

def save_to_db(msg):
    with db:
        cursor = db.cursor()
        try:
            cursor.execute("INSERT INTO MQTT_LOGS (topic, payload) VALUES (%s,%s)", (msg.topic, msg.payload))
        except (MySQLdb.Error, MySQLdb.Warning) as e:
            print('excepttion BD ' + e)
            return None

def post_data(payload,value):
    datos = {'VALUE': value,'data-from-broker': payload}
    r = requests.post(url, datos)
    r.status_code
    print('response POST' + str(r.status_code))

db = MySQLdb.connect("localhost","user_db","pass_db","db" )

当我在后台使用

python-t mqtt_subscribe.py运行python脚本时&

我会为其他客户端发布消息，但是在我的subscribe.py脚本运行数小时后，会发生套接字错误。

.log：

 ...
    1475614815: Received PINGREQ from my-paho-client
    1475614815: Sending PINGRESP to my-paho-client
    1475614872: New connection from xxx.xxx.xxx.xxx on port 1883.
    1475614872: Client device1 disconnected.
    1475614872: New client connected from xxx.xxx.xxx.xxx as device1(c0, k0, u'user1').
    1475614872: Sending CONNACK to device1(0, 0)
    1475614873: Received PUBLISH from device1(d0, q1, r0, m1, 'topic/data', ... (33 bytes))
    1475614873: Sending PUBACK to device1 (Mid: 1)
    1475614873: Sending PUBLISH to my-paho-client (d0, q0, r0, m0, 'topic/data', ... (33 bytes))
    1475614874: Received DISCONNECT from device1
    1475614874: Client device1 disconnected.
...
    1475625566: Received PINGREQ from my-paho-client
    1475625566: Sending PINGRESP to my-paho-client
    1475625626: Received PINGREQ from my-paho-client
    1475625626: Sending PINGRESP to my-paho-client
    1475625675: New connection from xxx.xxx.xxx.xxx on port 1883.
    1475625675: Client device1 disconnected.
    1475625675: New client connected from xxx.xxx.xxx.xxx as device1 (c0, k0, u'user1').
    1475625675: Sending CONNACK to device1 (0, 0)
    1475625677: Received PUBLISH from device1 (d0, q1, r0, m1, 'topic/data', ... (33 bytes))
    1475625677: Sending PUBACK to device1 (Mid: 1)
    1475625677: Sending PUBLISH to my-paho-client (d0, q0, r0, m0, 'topic/data', ... (33 bytes))
    1475625677: Socket error on client my-paho-client, disconnecting.
    1475625677: Received DISCONNECT from device1
...

有什么问题吗？有什么想法或建议吗

---

提前感谢

如果“on_message”方法中的代码引发异常，而您没有捕获到它，您将断开连接。 尝试取消对除print语句之外的所有语句的注释。可能以下语句之一正在引发异常

 save_to_db(msg)
 post_data(msg.payload,value)

---

插入数据库时，请使用

？

而不是

%s

。

---

如果我想捕获“on_message”事件，我应该在哪里编写“save_to_db”代码？你可以在那里编写代码，只要确保你捕获了那里的所有异常，如果你不想断开连接。试着理解，就因为我没有捕获异常，脚本就断开了连接？即使我捕捉到异常并且什么都不做脚本也不会停止？塞巴斯蒂安克，你能给我一个研究这个问题的参考吗？非常感谢。我在java实现中遇到了这个问题，我想python的行为也是如此。请查看javadoc-->MqttCallback-->messageArrived。这里描述了这种行为。“脚本断开”-我认为发生的情况是，未捕获的异常导致处理MQTT连接的线程死亡，这会中断TCP连接，也就是说，您不再订阅，因为您不再连接。如果您（在不可靠/不可预测的网络上连接时总是这样）明智地使用try/except（即不要简单地忽略所有异常，这比不使用try/except更糟糕），您将能够确保线程在异常发生时不会死亡。这是针对sqlite的，而不是针对MySQLdb的。

cursor.execute('''INSERT INTO users(name, phone, email, password)
                  VALUES(?,?,?,?)''', (name1,phone1, email1, password1))