I am trying to use a function node and the mqtt package in a function node.
So my code is executed on start (which is probably what's causing problems starting the flows here).
I do not have any code that handles closing mqtt connection/, the instance is started upon a deployment and never exited.
And what's even funnier , the code is doing console.log on connection. after first redeploy (restarting on docker, then redeploying), and after each redeploy i am seeing another connection in my EMQX dashboard.
And the message is received successfully and processed to the output (only one, a little bit slower than when we have only one client connected)
How can i successfully close a mqtt connection from a function node.
Tried saving the mqtt.connect object in context, and using it on stop, but no luck.
Here is the code:
// If no existing client, create a new one
var client = mqtt.connect(`${env.get('configuration').protocol}${env.get('configuration').url}`, {
port: env.get('configuration').MQTTport,
username: env.get('configuration').MQTTusername,
password: env.get('configuration').MQTTpassword,
clean: true
});
client.on("connect", function () {
console.log("connected")
node.status({fill:"green",shape:"dot",text:"connected"});
});
client.on("error", function (error) {
node.status({fill:"red",shape:"ring",text:"disconnected"});
console.log(`modbus-calendar-MQTT: ${env.get('configuration').hvacId} \n ${error}`);
if (error.toString().includes('Authentication failed')) {
var delay = Math.random() * (60000 - 20000) + 20000;
setTimeout(() => {
console.log("Attempting to reconnect...");
client.reconnect();
}, delay);
}
});
client.subscribe(`modbus-calendar/${env.get('configuration').hvacId}/#`, { qos: 2 });
client.on('message', function (topic, message, packet) {
msg.received = JSON.parse(message).Data;
msg.topic = topic;
node.send(msg);
});
EDIT #1 I know i can turn on the Use Username as Client ID and only keep one connection for a username, but designing to run the flow on a raspberry pi, and actually have not tested if this haves a particular memory impact.
EDIT #2 When Use Username as Client ID is enabled after each deploy / restart flows memory memory usage is increased by 3.9-4.2mb (not happening when all flows disabled). The increase is 2.8-3.2mb when Use Username as Client ID is disabled.
