[Bug]: Client continuously connects, gets disconnected, reconnects

[QuentinFarizon]

MQTTjs Version

5.9.0

Broker

Mosquitto (from Stackhero)

Environment

NodeJS

Description

When I connect to the broker, the connection gets closed very quickly after established.
I can chain one or two publish or subscribe immediately after connection success, but 500ms - 1s later it gets closed.

Minimal Reproduction

return mqtt.connect(<STACKHERO_MOSQUITTO_URL_TLS>, {
auth: <...>
})

Debug logs

  mqttjs:client MqttClient :: version: 5.9.0 +0ms
  mqttjs:client MqttClient :: environment node +0ms
  mqttjs:client MqttClient :: options.protocol mqtts +0ms
  mqttjs:client MqttClient :: options.protocolVersion 4 +0ms
  mqttjs:client MqttClient :: options.username admin +0ms
  mqttjs:client MqttClient :: options.keepalive 60 +0ms
  mqttjs:client MqttClient :: options.reconnectPeriod 1000 +0ms
  mqttjs:client MqttClient :: options.rejectUnauthorized undefined +0ms
  mqttjs:client MqttClient :: options.properties.topicAliasMaximum undefined +0ms
  mqttjs:client MqttClient :: clientId mqttjs_4fdb8f15 +0ms
  mqttjs:client MqttClient :: setting up stream +0ms
  mqttjs:client connect :: calling method to clear reconnect +1ms
  mqttjs:client _clearReconnect : clearing reconnect timer +0ms
  mqttjs:client connect :: using streamBuilder provided to client to create stream +0ms
  mqttjs:client connect :: pipe stream to writable stream +22ms
  mqttjs:client connect: sending packet `connect` +0ms
  mqttjs:client _writePacket :: packet: {
  mqttjs:client   cmd: 'connect',
  mqttjs:client   protocolId: 'MQTT',
  mqttjs:client   protocolVersion: 4,
  mqttjs:client   clean: true,
  mqttjs:client   clientId: 'mqttjs_4fdb8f15',
  mqttjs:client   keepalive: 60,
  mqttjs:client   username: 'admin',
  mqttjs:client   password: '<my-password>',
  mqttjs:client   properties: undefined
  mqttjs:client } +0ms
  mqttjs:client _writePacket :: emitting `packetsend` +1ms
  mqttjs:client _writePacket :: writing to stream +0ms
  mqttjs:client _writePacket :: writeToStream result true +5ms
(node:1534689) [SEQUELIZE0018] DeprecationWarning: The "field" option in attribute definitions has been renamed to "columnName".
(Use `node --trace-deprecation ...` to show where the warning was created)
  mqttjs:client writable stream :: parsing buffer +38ms
  mqttjs:client parser :: on packet push to packets array. +0ms
  mqttjs:client work :: getting next packet in queue +0ms
  mqttjs:client work :: packet pulled from queue +0ms
  mqttjs:client _handlePacket :: emitting packetreceive +0ms
  mqttjs:client _handleConnack +1ms
  mqttjs:client _setupKeepaliveManager :: keepalive 60 (seconds) +0ms
  mqttjs:client KeepaliveManager: set keepalive to 60000ms +0ms
  mqttjs:client connect :: sending queued packets +1ms
  mqttjs:client deliver :: entry undefined +0ms
  mqttjs:client _resubscribe +0ms
  mqttjs:client (mqttjs_4fdb8f15)stream :: on close +1s
  mqttjs:client _flushVolatile :: deleting volatile messages from the queue and setting their callbacks as error function +0ms
  mqttjs:client stream: emit close to MqttClient +0ms
  mqttjs:client close :: connected set to `false` +0ms
  mqttjs:client close :: clearing connackTimer +0ms
  mqttjs:client _destroyKeepaliveManager :: destroying keepalive manager +0ms
  mqttjs:client close :: calling _setupReconnect +0ms
  mqttjs:client _setupReconnect :: emit `offline` state +0ms
MQTT offline
  mqttjs:client _setupReconnect :: set `reconnecting` to `true` +1ms
  mqttjs:client _setupReconnect :: setting reconnectTimer for 1000 ms +0ms
  mqttjs:client reconnectTimer :: reconnect triggered! +1s
  mqttjs:client _reconnect: emitting reconnect to client +1ms
MQTT broker reconnected
  mqttjs:client _reconnect: calling connect +0ms
  mqttjs:client connect :: calling method to clear reconnect +0ms
  mqttjs:client _clearReconnect : clearing reconnect timer +0ms
  mqttjs:client connect :: using streamBuilder provided to client to create stream +0ms
  mqttjs:client connect :: pipe stream to writable stream +2ms
  mqttjs:client connect: sending packet `connect` +0ms
  mqttjs:client _writePacket :: packet: {
  mqttjs:client   cmd: 'connect',
  mqttjs:client   protocolId: 'MQTT',
  mqttjs:client   protocolVersion: 4,
  mqttjs:client   clean: true,
  mqttjs:client   clientId: 'mqttjs_4fdb8f15',
  mqttjs:client   keepalive: 60,
  mqttjs:client   username: 'admin',
  mqttjs:client   password: '<my-password>',
  mqttjs:client   properties: undefined
  mqttjs:client } +0ms
  mqttjs:client _writePacket :: emitting `packetsend` +0ms
  mqttjs:client _writePacket :: writing to stream +0ms
  mqttjs:client _writePacket :: writeToStream result true +1ms
  mqttjs:client writable stream :: parsing buffer +34ms
  mqttjs:client parser :: on packet push to packets array. +1ms
  mqttjs:client work :: getting next packet in queue +0ms
  mqttjs:client work :: packet pulled from queue +0ms
  mqttjs:client _handlePacket :: emitting packetreceive +0ms
  mqttjs:client _handleConnack +0ms
  mqttjs:client _setupKeepaliveManager :: keepalive 60 (seconds) +0ms
  mqttjs:client KeepaliveManager: set keepalive to 60000ms +0ms
  mqttjs:client connect :: sending queued packets +0ms
  mqttjs:client deliver :: entry undefined +0ms
  mqttjs:client _resubscribe +0ms
  mqttjs:client (mqttjs_4fdb8f15)stream :: on close +1s
  mqttjs:client _flushVolatile :: deleting volatile messages from the queue and setting their callbacks as error function +0ms
  mqttjs:client stream: emit close to MqttClient +0ms
  mqttjs:client close :: connected set to `false` +0ms
  mqttjs:client close :: clearing connackTimer +0ms
  mqttjs:client _destroyKeepaliveManager :: destroying keepalive manager +0ms
  mqttjs:client close :: calling _setupReconnect +0ms
  mqttjs:client _setupReconnect :: emit `offline` state +0ms
MQTT offline
  mqttjs:client _setupReconnect :: set `reconnecting` to `true` +1ms
  mqttjs:client _setupReconnect :: setting reconnectTimer for 1000 ms +0ms
  mqttjs:client reconnectTimer :: reconnect triggered! +1s
  mqttjs:client _reconnect: emitting reconnect to client +0ms
MQTT broker reconnected
  mqttjs:client _reconnect: calling connect +0ms
  mqttjs:client connect :: calling method to clear reconnect +0ms
  mqttjs:client _clearReconnect : clearing reconnect timer +0ms
  mqttjs:client connect :: using streamBuilder provided to client to create stream +1ms
  mqttjs:client connect :: pipe stream to writable stream +1ms
  mqttjs:client connect: sending packet `connect` +0ms
  mqttjs:client _writePacket :: packet: {
  mqttjs:client   cmd: 'connect',
  mqttjs:client   protocolId: 'MQTT',
  mqttjs:client   protocolVersion: 4,
  mqttjs:client   clean: true,
  mqttjs:client   clientId: 'mqttjs_4fdb8f15',
  mqttjs:client   keepalive: 60,
  mqttjs:client   username: 'admin',
  mqttjs:client   password: '<my-password>',
  mqttjs:client   properties: undefined
  mqttjs:client } +0ms
  mqttjs:client _writePacket :: emitting `packetsend` +0ms
  mqttjs:client _writePacket :: writing to stream +0ms
  mqttjs:client _writePacket :: writeToStream result true +1ms
  mqttjs:client writable stream :: parsing buffer +44ms
  mqttjs:client parser :: on packet push to packets array. +0ms
  mqttjs:client work :: getting next packet in queue +0ms
  mqttjs:client work :: packet pulled from queue +0ms
  mqttjs:client _handlePacket :: emitting packetreceive +0ms
  mqttjs:client _handleConnack +0ms
  mqttjs:client _setupKeepaliveManager :: keepalive 60 (seconds) +0ms
  mqttjs:client KeepaliveManager: set keepalive to 60000ms +0ms
  mqttjs:client connect :: sending queued packets +1ms
  mqttjs:client deliver :: entry undefined +0ms
  mqttjs:client _resubscribe +0ms
  mqttjs:client (mqttjs_4fdb8f15)stream :: on close +1s
  mqttjs:client _flushVolatile :: deleting volatile messages from the queue and setting their callbacks as error function +0ms
  mqttjs:client stream: emit close to MqttClient +0ms
  mqttjs:client close :: connected set to `false` +0ms
  mqttjs:client close :: clearing connackTimer +0ms
  mqttjs:client _destroyKeepaliveManager :: destroying keepalive manager +0ms
  mqttjs:client close :: calling _setupReconnect +0ms
  mqttjs:client _setupReconnect :: emit `offline` state +0ms
MQTT offline
  mqttjs:client _setupReconnect :: set `reconnecting` to `true` +0ms
  mqttjs:client _setupReconnect :: setting reconnectTimer for 1000 ms +0ms

[robertsLando]

The reason why the connection is closed is not clear looking at the logs, I just see the stream is closed after 1s receiving the connack.

mqttjs:client (mqttjs_4fdb8f15)stream :: on close +1s

This makes me think it's the broker closing the connection for some reason (like another client connecting with the same clientId). I suggest to check your logs on broker side