mqtt node js模块的Mosquitto持久性问题

Question

我正在尝试使用 mosquitto 代理运行基本队列实现，当消费者和生产者正常运行时它工作正常。如果我运行生产者然后我运行消费者我无法获得消息（数据）。我在将消息发布到主题时使用 qos:2。我正在使用 mqtt.js

的 nodejs 语言

consumer.js

const mqtt = require ('mqtt');
var options = {}
options.clientId = 'mqttjs_consumer'
options.clean = false
options.debug = true
var client  = mqtt.connect('mqtt://localhost',options);

client.on('connect', function () {
  client.subscribe('topic/sample',function(){
    console.log('client has subscribed successfully');
  });

});

client.on('message', function (topic, message){
  console.log(message.toString());
});

Producer.js

const mqtt = require ('mqtt');
var options = {}
options.clientId = 'mqttjs_producer'
options.debug = true
var client  = mqtt.connect('mqtt://localhost',options);

client.on('connect', function(){
  client.publish('topic/sample','message_data',{qos:2},function(err,status){
    console.log(err,status)
    process.exit(0)
  })
});

Answer 1

您需要订阅 QOS 2，而不仅仅是使用 QOS 2 发布。

const mqtt = require ('mqtt');
var options = {}
options.clientId = 'mqttjs_consumer'
options.clean = false
options.debug = true
var client  = mqtt.connect('mqtt://localhost',options);

client.on('connect', function () {
  client.subscribe('topic/sample',{qos:2}, function(){
    console.log('client has subscribed successfully');
  });

});

client.on('message', function (topic, message){
  console.log(message.toString());
});

mqtt node js模块的Mosquitto持久性问题

Mosquitto persitence problems with mqtt nodejs module

mqtt

mosquitto