Received an MQTT packet from a not connected client (CONNECT not sent yet)

[paulocabrita-ionos]

Dear all,

I'm doing some tests using HONO + DITTO and I'm having an issue. I'm following the C2E Tour and following the instructions. All of them worked fine but when I try to use the MQTT adapter instead of the HTTP. I have 2 exceptions:

2023-10-09 17:32:06,003 ERROR [io.qua.ver.cor.run.VertxCoreRecorder] (vert.x-eventloop-thread-1) Uncaught exception received by Vert.x: java.lang.IllegalStateException: Received an MQTT packet from a not connected client (CONNECT not sent yet)                             ││     at io.vertx.mqtt.impl.MqttServerConnection.checkConnected(MqttServerConnection.java:468)                                                                                                                                                                                    ││     at io.vertx.mqtt.impl.MqttServerConnection.handlePublish(MqttServerConnection.java:361)                                                                                                                                                                                     ││     at io.vertx.mqtt.impl.MqttServerConnection.handleMessage(MqttServerConnection.java:158)                                                                                                                                                                                     ││     at io.vertx.mqtt.impl.MqttServerImpl.lambda$null$1(MqttServerImpl.java:102)                                                                                                                                                                                                 ││     at io.vertx.core.impl.EventLoopContext.emit(EventLoopContext.java:55)                                                                                                                                                                                                       ││     at io.vertx.core.impl.ContextBase.emit(ContextBase.java:239)                                                                                                                                                                                                                ││     at io.vertx.core.net.impl.NetSocketImpl.handleMessage(NetSocketImpl.java:390)                                                                                                                                                                                               │
│     at io.vertx.core.net.impl.ConnectionBase.read(ConnectionBase.java:157)                                                                                                                                                                                                      │
│     at io.vertx.core.net.impl.VertxHandler.channelRead(VertxHandler.java:153)                                                                                                                                                                                                   │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)                                                                                                                                                                   │
│     at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286)                                                                                                                                                                                         │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)                                                                                                                                                                   │
│     at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346)                                                                                                                                                                               │
│     at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:333)                                                                                                                                                                               │
│     at io.netty.handler.codec.ReplayingDecoder.callDecode(ReplayingDecoder.java:349)                                                                                                                                                                                            │
│     at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290)                                                                                                                                                                                   │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)                                                                                                                                                                   │
│     at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)                                                                                                                                                                        │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)                                                                                                                                                                 │
│     at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)                                                                                                                                                                                 │
│     at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:800)                                                                                                                                                    │
│     at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:499)                                                                                                                                                                                              │
│     at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:397)                                                                                                                                                                                                       │
│     at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)                                                                                                                                                                             │
│     at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)                                                                                                                                                                                                │
│     at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)                                                                                                                                                                                    │
│     at java.base/java.lang.Thread.run(Unknown Source)
2023-10-09 17:32:06,003 ERROR [io.qua.ver.cor.run.VertxCoreRecorder] (vert.x-eventloop-thread-1) Uncaught exception received by Vert.x: java.lang.IllegalStateException: Received an MQTT packet from a not connected client (CONNECT not sent yet)                             │
│     at io.vertx.mqtt.impl.MqttServerConnection.checkConnected(MqttServerConnection.java:468)                                                                                                                                                                                    │
│     at io.vertx.mqtt.impl.MqttServerConnection.handleDisconnect(MqttServerConnection.java:445)                                                                                                                                                                                  │
│     at io.vertx.mqtt.impl.MqttServerConnection.handleMessage(MqttServerConnection.java:200)                                                                                                                                                                                     │
│     at io.vertx.mqtt.impl.MqttServerImpl.lambda$null$1(MqttServerImpl.java:102)                                                                                                                                                                                                 │
│     at io.vertx.core.impl.EventLoopContext.emit(EventLoopContext.java:55)                                                                                                                                                                                                       │
│     at io.vertx.core.impl.ContextBase.emit(ContextBase.java:239)                                                                                                                                                                                                                │
│     at io.vertx.core.net.impl.NetSocketImpl.handleMessage(NetSocketImpl.java:390)                                                                                                                                                                                               │
│     at io.vertx.core.net.impl.ConnectionBase.read(ConnectionBase.java:157)                                                                                                                                                                                                      │
│     at io.vertx.core.net.impl.VertxHandler.channelRead(VertxHandler.java:153)                                                                                                                                                                                                   │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)                                                                                                                                                                   │
│     at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286)                                                                                                                                                                                         │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)                                                                                                                                                                   │
│     at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346)                                                                                                                                                                               │
│     at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:318)                                                                                                                                                                                   │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)                                                                                                                                                                 │
│     at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)                                                                                                                                                                   │
│     at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)                                                                                                                                                                        │
│     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)                                                                                                                                                                 ││     at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)                                                                                                                                                                 ││     at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)                                                                                                                                                                                 ││     at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:800)                                                                                                                                                    ││     at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:499)                                                                                                                                                                                              ││     at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:397)                                                                                                                                                                                                       ││     at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)                                                                                                                                                                             ││     at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)                                                                                                                                                                                                ││     at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)                                                                                                                                                                                    ││     at java.base/java.lang.Thread.run(Unknown Source)

My goal:

• to send data to the Hono MQTT endpoint and having a DT (from Ditto) changed with the values that are being sent from a Python script.

What I have done:

• Creation of a new Digital Twin (DT) using the demo tenant of the Tour
• Sending data to the DT using the Hono HTTP endpoint;
• Checking if the values of the DT are changed. And yes, it works perfectly;
• Sending data to the same DT using the Hono MQTT endpoint. I created a json payload with the structure of my DT. When I send the MQTT payload (using a python script), I have the 2 above exceptions and the python script gives no error;

What I have followed:

• C2E Tour;
• This python script from the Examples folder of the Ditto Repo. This Repo uses Mosquitto and not Hono;

I'm not sure what is this but I think it's related to this issue: vert-x3/vertx-mqtt#94

Any thoughts?

[sophokles73]

This is not necessarily related to vert-x3/vertx-mqtt#94 but might also have its reason in your client starting to send PUBLISH packets before it has received the CONNACK from Hono. Can you check in your Python MQTT client if you are actually waiting for the CONNACK before sending any data?

[paulocabrita-ionos]

Yes. You are absolutely right. It was related to the connect stage. I had to put a while loop in order to fix it.

If someone will face this issue, I did the following:

client.connect(broker_ip, MQTT_BROKER_PORT, 60)
while not client.connected_flag: #wait in loop
    print("In wait loop")
    time.sleep(1)

But... I'm facing another issue which I think it's related to a no such endpoint in the mqtt adapter.
I will close this one and open another one.

Thank you very much.