I have a MQTT Client (lets call it Client-1) using java PAHO, this is pub and sub to topics without problem,
on the other side of the globe I have another client (lets call it SuperClient) that can public topics as commands for my Clients...
one of those commands is "DISCONNECT-NOW", in my Client-1 I have implemented the callback where I recieve correctly that msg, however, when I try to disconnect according to that command I get an Exception:
ReasonCode: 32107
Message: Disconnecting using a Callback-method is not allowed
LocalizedMsg: Disconnecting using a Callback-method is not allowed
Exception: Disconnecting using a Callback-method is not allowed (32107)
Disconnecting using a Callback-method is not allowed (32107)
at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:31)
at
org.eclipse.paho.client.mqttv3.internal.ClientComms.disconnect(ClientComms.java:460)
at
org.eclipse.paho.client.mqttv3.MqttAsyncClient.disconnect(MqttAsyncClient.java:632)
at
org.eclipse.paho.client.mqttv3.MqttAsyncClient.disconnect(MqttAsyncClient.java:601)
at
org.eclipse.paho.client.mqttv3.MqttAsyncClient.disconnect(MqttAsyncClient.java:608)
at
org.eclipse.paho.client.mqttv3.MqttClient.disconnect(MqttClient.java:256)
at co.ve.de.MqttBroker.disconnect(MqttBroker.java:94) at
co.ve.de.Implementation.lambda$1(Implementation.java:53) at
co.ve.de.MqttBroker$1.messageArrived(MqttBroker.java:132) at
org.eclipse.paho.client.mqttv3.internal.CommsCallback.deliverMessage(CommsCallback.java:475)
at
org.eclipse.paho.client.mqttv3.internal.CommsCallback.handleMessage(CommsCallback.java:379)
at
org.eclipse.paho.client.mqttv3.internal.CommsCallback.run(CommsCallback.java:183)
at java.lang.Thread.run(Unknown Source)
my question: is there any way to disconnect asynchronously from the network without doing some weird long polling ??
Thanks!
Try running the call to disconnect on a separate thread.
messageArrived(java.lang.String topic, MqttMessage message) {
if (disconnect){
new Thread().run(new Runnable(){
public void run() {
client.disconnect();
}
});
}
}
Related
I have an embedded ActiveMQ Artemis 2.17.0 broker that has no pre-configured queues. I'd like for the client to connect to the broker and have its queue created automatically if it doesn't exist. This works just fine the 1st time when I run the client but on the second time I connect again to the broker the client throws an error :
errorType=QUEUE_EXISTS message=AMQ229019: Queue hornetq already exists on address router
Is it possible to configure the client or the server in such a way that if a queue is already in existence it should not attempt to recreate it again?
Below are the programs I am running:
Server
try {
ActiveMQServer server = new ActiveMQServerImpl(new ConfigurationImpl()
.setPersistenceEnabled(true)
.setBindingsDirectory("./router/data/bindings")
.setLargeMessagesDirectory("./router/data/large")
.setPagingDirectory("./router/data/paging")
.setJournalDirectory("./router/data/journal")
.setSecurityEnabled(false)
.addAcceptorConfiguration("tcp", "tcp://0.0.0.0:61617?protocols=CORE,AMQP"));
server.start();
} catch (Exception ex) {
System.err.println(ex);
}
Client
ServerLocator serverLocator = ActiveMQClient.createServerLocator("tcp://127.0.0.1.3:61617");
ClientSessionFactory factory = serverLocator.createSessionFactory();
ClientSession session = factory.createSession();
session.createQueue(new QueueConfiguration("router::hornetq")
.setAutoCreateAddress(Boolean.FALSE)
.setAutoCreated(Boolean.FALSE)
.setRoutingType(RoutingType.ANYCAST));
ClientProducer producer = session.createProducer("router::hornetq");
ClientMessage message = session.createMessage(true);
message.getBodyBuffer().writeString("Core Queue Message");
producer.send(message);
session.start();
ClientConsumer consumer = session.createConsumer("router::hornetq");
ClientMessage msgReceived = consumer.receive();
System.out.println("message = " + msgReceived.getBodyBuffer().readString());
session.close();
I'm using the fully qualified queue name here (i.e. router::hornetq) because I have multiple queues on the router address.
Your client is using the core API which is a low-level API that does not support auto-queue creation. Your client is creating (or attempting to create) the queue manually, e.g.:
session.createQueue(new QueueConfiguration("router::hornetq")
.setAutoCreateAddress(Boolean.FALSE)
.setAutoCreated(Boolean.FALSE)
.setRoutingType(RoutingType.ANYCAST));
The exception you're seeing is no doubt being thrown here if the queue exists already. Creating a queue is not idempotent so you have 3 options from what I can see:
Simply catch the ActiveMQQueueExistsException that is being thrown here and ignore it.
Use ClientSession.queueQuery to see if the queue exists before you attempt to create it. If it exists then don't try to create it again. If it doesn't exist then create it. That said, if you have lots of clients like this running concurrently it's still possible you could get an ActiveMQQueueExistsException due to race conditions between the clients.
Use a client/protocol that supports auto-creation like the core JMS client or AMQP.
A few other things are worth mentioning:
Since you're not explicitly calling ClientSession.createAddress() you probably want to use setAutoCreateAddress(Boolean.TRUE).
Your consumer doesn't have to use router::hornetq. It can just use hornetq and it will receive any messages sent to the hornetq queue. Queue names are universally unique in the broker.
I am trying to implement an interface for my erlang program using jinterface. When I call the command OtpNode otpNode = new OtpNode(nodeName, cookie); java throws an IOException with
java.io.IOException: Nameserver not responding on DESKTOP-GIR29G3 when publishing javanode.
It doesn't seem to be common problem for people as I couldn't find anything similar online. It's a local node with the node name being "javanode" with no fullstops or dashes. Why would there be a DNS issue on a local node?
I have tried starting an erlang node in the directory the java program is started as well as starting the erlang console on my pc, but I'm very new to erlang so those were just wild guesses that some erlang VM must be running.
Here is the code that may help:
public Erlterface()
{
Thread t = new Thread(new Runnable() {
public void run() {
setupMBox();
}
});
t.start();
}
private void setupMBox()
{
try {
String nodeName = "javanode";
String cookie = "jinterface";
//String[] names = OtpEpmd.lookupNames();
OtpNode otpNode = new OtpNode(nodeName, cookie); //CRASH HAPPENS HERE
OtpMbox Mbox = otpNode.createMbox("javaserver");
The error from the console:
Connected to the target VM, address: '127.0.0.1:54025', transport: 'socket'
java.io.IOException: Nameserver not responding on DESKTOP-GIR29G3 when publishing javanode
at com.stellar.base.schedule.com.ericsson.otp.erlang.OtpEpmd.r4_publish(OtpEpmd.java:344)
at com.stellar.base.schedule.com.ericsson.otp.erlang.OtpEpmd.publishPort(OtpEpmd.java:141)
at com.stellar.base.schedule.com.ericsson.otp.erlang.OtpNode$Acceptor.publishPort(OtpNode.java:784)
at com.stellar.base.schedule.com.ericsson.otp.erlang.OtpNode$Acceptor.<init>(OtpNode.java:776)
at com.stellar.base.schedule.com.ericsson.otp.erlang.OtpNode.init(OtpNode.java:232)
at com.stellar.base.schedule.com.ericsson.otp.erlang.OtpNode.<init>(OtpNode.java:196)
at com.stellar.base.schedule.com.ericsson.otp.erlang.OtpNode.<init>(OtpNode.java:149)
at com.stellar.base.schedule.Erlterface.setupMBox(Erlterface.java:40)
at com.stellar.base.schedule.Erlterface.access$000(Erlterface.java:16)
at com.stellar.base.schedule.Erlterface$1.run(Erlterface.java:26)
at java.lang.Thread.run(Thread.java:745)
Thanks in advance
Dale
UPDATE ADDITIONAL INFORMATION:
I went into a dive to try and figure out where exactly the train leaves the rails but I'm taking wild guesses as to what I should flag as potential issues. I just want to add some additional information here to help:
In OptEpmd the following is caught before the io exception is thrown
java.net.ConnectException: Connection refused: connect
The final source is the native DeulSocketImpl class that I suppose calls on windows to do the final connection thingamabob ad it fails:
static native int connect0(int var0, InetAddress var1, int var2) throws IOException;
Am I missing something in setting up the erlang node? I surely don't have to start it manually? I've diabled my firewall completely to test it. How do I figure out why the connection was refused?
When I am trying to connect solace VMR Server and deliver the messages from a Java client called Vertx AMQP Bridge.
I am able to connect the Solace VMR Server but after connecting, not able to send messages to solace VMR.
I am using below sender code from vertx client.
public class Sender extends AbstractVerticle {
private int count = 1;
// Convenience method so you can run it in your IDE
public static void main(String[] args) {
Runner.runExample(Sender.class);
}
#Override
public void start() throws Exception {
AmqpBridge bridge = AmqpBridge.create(vertx);
// Start the bridge, then use the event loop thread to process things thereafter.
bridge.start("13.229.207.85", 21196,"UserName" ,"Password", res -> {
if(!res.succeeded()) {
System.out.println("Bridge startup failed: " + res.cause());
return;
}
// Set up a producer using the bridge, send a message with it.
MessageProducer<JsonObject> producer =
bridge.createProducer("T/GettingStarted/pubsub");
// Schedule sending of a message every second
System.out.println("Producer created, scheduling sends.");
vertx.setPeriodic(1000, v -> {
JsonObject amqpMsgPayload = new JsonObject();
amqpMsgPayload.put(AmqpConstants.BODY, "myStringContent" + count);
producer.send(amqpMsgPayload);
System.out.println("Sent message: " + count++);
});
});
}
}
I am getting the error below:
Bridge startup failed: io.vertx.core.impl.NoStackTraceThrowable:
Error{condition=amqp:not-found, description='SMF AD bind response
error', info={solace.response_code=503, solace.response_text=Unknown
Queue}} Apr 27, 2018 3:07:29 PM io.vertx.proton.impl.ProtonSessionImpl
WARNING: Receiver closed with error
io.vertx.core.impl.NoStackTraceThrowable:
Error{condition=amqp:not-found, description='SMF AD bind response
error', info={solace.response_code=503, solace.response_text=Unknown
Queue}}
I have created queue and also topic correctly in solace VMR but not able to send/receive messages. Am I missing any configuration from solace VMR Server side? Is there any code-change required in the Vertx Sender Java code above? I am getting the error trace above when delivering message. Can someone help on the same?
Vertx AMQP Bridge Java client :https://vertx.io/docs/vertx-amqp-bridge/java/
There are a few different reason why you may be encountering this error.
It could be that the client is not authorized to publish guaranteed messages. To fix this, you need to enable "guaranteed endpoint create" in the client-profile on the Solace router side.
It may also be that the application is using Reply Handling. This is not currently supported with the Solace router. Support for this will be added in the 8.11 release of the Solace VMR. A workaround for this would be to set ReplyHandlingSupport to false.
AmqpBridgeOptions().setReplyHandlingSupport(false);
There is also a known issue in the Solace VMR which causes this error when unsubscribing from a durable topic endpoint. A fix for this issue will also be in the 8.11 release of the Solace VMR. A workaround for this is to disconnect the client without first unsubscribing.
How to handle the error "UNet Client Disconnect Error: Timeout"? How not reboot the application, when it occurs?
I now resolve this issue.
I think this can help you too.
myClient.RegisterHandler(MsgType.Error, OnError);
void OnError(NetworkMessage msg){
//Error handler code
}
This Error client receive with "UNET Client Disconnect Error: Timeout".
My solution: If i not have server. I set current client as Server.
I am writing an apache-camel RabbitMQ consumer. I would like to react somehow to connection problems (i.e. try to reconnect). Is it possible to configure apache-camel to automatically reconnect?
If not, how can I find out that a connection to the queue was interrupted? I've done the following test:
start the queue (and some producer)
start my consumer (it was getting messages as expected)
stop the queue (the messages stopped arriving, as expected, but no exception was thrown)
start the queue (no new messages were received)
I am using camel in Scala (via akka-camel), but a Java solution would be probably also OK
You can pass in the flag automaticRecoveryEnabled=true to the URI, Camel will reconnect if the connection is lost.
For automatic RabbitMQ resource recovery (Connections/Channels/Consumers/Queues/Exchanages/Bindings) when failures occur, check out Lyra (which I authored). Example usage:
Config config = new Config()
.withRecoveryPolicy(new RecoveryPolicy()
.withMaxAttempts(20)
.withInterval(Duration.seconds(1))
.withMaxDuration(Duration.minutes(5)));
ConnectionOptions options = new ConnectionOptions().withHost("localhost");
Connection connection = Connections.create(options, config);
The rest of the API is just the amqp-client API, except your resources are automatically recovered when failures occur.
I'm not sure about camel-rabbitmq specifically, but hopefully there's a way you can swap in your own resource creation via Lyra.
Current camel-rabbitmq just create a connection and the channel when the consumer or producer is started. So it don't have a chance to catch the connection exception :(.