尝试实现 Mqtt 5.0 keepAlive 功能 - 但我仍然被 Broker 断开连接

Question

我想我会添加

keepalive: 120

到我的 Mqtt Broker 连接代码，但我仍然被 Broker 断开连接并显示以下消息（根据我的 Chrome 网络选项卡）：

.M.K..HThe client was idle for too long without sending an MQTT control packet.

例如

这是我的

Angular 13

代码中的连接字符串（带有

keepalive: 120

）

    getBrokerConnection(): IMqttServiceOptions {
        const d = new Date();
        const tempId =
            'HarBrowser' + (d.getUTCMinutes() + d.getUTCMilliseconds() + Math.random()).toFixed(8).toString();
        const username = atob(this.config.getConfig('mqttUser'));
        const password = atob(this.config.getConfig('mqttPass'));
        const brokerAddr = this.config.getConfig('mqttBrokerAddress');
        const port = this.config.getConfig('mqttPort');
        const protocol = this.config.getConfig('mqttProtocol');
        return {
            hostname: brokerAddr,
            port: port,
            path: '/mqtt',
            clean: true, // CleanSession=true does not persist the prev client session
            connectTimeout: 30000,
            keepalive: 120,
            reconnectPeriod: 0, // 0 to disable auto-reconn (to prevent many front-end errors)
            clientId: tempId,
            username: username,
            password: password,
            protocol: protocol,
            connectOnCreate: false,
            protocolVersion: 5,
        };
    }

据我所知，

Mqtt client

负责向代理发送

pingreq

以保持连接有效（根据 https://docs.oasis-open.org/mqtt/mqtt/v5. 0/os/mqtt-v5.0-os.html#_Toc3901045)

我确实多次看到此事件记录到 Chrome 控制台，所以我假设这是我的 Mqtt 客户端根据

pingreq

参数发送该

keepalive

：

 this.mqttService.onPacketsend.subscribe((res) => console.log(`onPacketsend event ${res}`)); 

现在我应该以编程方式发送

pingreq

，还是应该将它内置到这个Angular 包装器中到

mqtt.js

？我有点不清楚我做错了什么，因为我被经纪人断开了连接。