This is probably some silly mistake I'm missing, but here is the issue:
I am trying to insert a simple "hello" message into a Rabbit queue, with a predefined exchange and routing key.
This is the code that I am using:
private static void send_equity_task_to_rabbitmq(ConnectionFactory factory) throws IOException,TimeoutException{
Connection connection = factory.newConnection();
Channel channel = connection.createChannel();
channel.queueDeclare("b", false, false, false, null);
channel.exchangeDeclare("b", "direct");
channel.basicPublish("b","b",null, "hello".getBytes());
channel.close();
connection.close();
}
public static void main(String[] argv) throws TimeoutException,IOException {
ConnectionFactory factory = new ConnectionFactory();
factory.setHost("127.0.0.1");
Date start_time= Calendar.getInstance().getTime();
Long start_time_timestamp=System.currentTimeMillis();
System.out.println("[INFO] Starting connection to queue at:"+start_time);
send_equity_task_to_rabbitmq(factory);
Long end_time_timestamp=System.currentTimeMillis();
System.out.println("[INFO] Message sent and processed successfully after:"+ (end_time_timestamp-start_time_timestamp)+" miliseconds");
}
}
The code runs without any error. However, when I check the amount of records inside the "b" queue, I get:
$ rabbitmqctl list_queues
Listing queues ...
b 0
...done.
I don't have consumers for this queue at the moment, so I assume since it has 0 records, that I am using basicPublish badly.
What could be wrong?
Thank you.
I think you need to bind the queue to the exchange. You've created a queue called "b" and an exchange called "b". The exchange will distribute messages to queues that are bound to it, using the "b" routingKey, but as the "b" queue isn't bound to the "b" exchange, the "b" exchange doesn't publish to that queue.
Related
I need to send my messages to Dead letter queue from azure topic subscription incase of any error while reading and processing the message from topic. So I tried testing pushing message directly to DLQ.
My sample code will be like
static void sendMessage()
{
// create a Service Bus Sender client for the queue
ServiceBusSenderClient senderClient = new ServiceBusClientBuilder()
.connectionString(connectionString)
.sender()
.topicName(topicName)
.buildClient();
// send one message to the topic
senderClient.sendMessage(new ServiceBusMessage("Hello, World!"));
}
static void resceiveAsync() {
ServiceBusReceiverAsyncClient receiver = new ServiceBusClientBuilder()
.connectionString(connectionString)
.receiver()
.topicName(topicName)
.subscriptionName(subName)
.buildAsyncClient();
// receive() operation continuously fetches messages until the subscription is disposed.
// The stream is infinite, and completes when the subscription or receiver is closed.
Disposable subscription = receiver.receiveMessages().subscribe(message -> {
System.out.printf("Id: %s%n", message.getMessageId());
System.out.printf("Contents: %s%n", message.getBody().toString());
}, error -> {
System.err.println("Error occurred while receiving messages: " + error);
}, () -> {
System.out.println("Finished receiving messages.");
});
// Continue application processing. When you are finished receiving messages, dispose of the subscription.
subscription.dispose();
// When you are done using the receiver, dispose of it.
receiver.close();
}
I tried getting the deadletter queue path
String dlq = EntityNameHelper.formatDeadLetterPath(topicName);
I got path of dead letter queue like = "mytopic/$deadletterqueue"
But It's not working while passing path as topic name. It throwing a Entity topic not found exception.
Any one can you please advise me on this
Reference :
How to move error message to Azure dead letter queue using Java?
https://learn.microsoft.com/en-us/azure/service-bus-messaging/service-bus-dead-letter-queues#moving-messages-to-the-dlq
How to push the failure messages to Azure service bus Dead Letter Queue in Spring Boot Java?
https://learn.microsoft.com/en-us/azure/service-bus-messaging/service-bus-java-how-to-use-topics-subscriptions-legacy#receive-messages-from-a-subscription
You probably know that a message will be automatically moved to the deadletter queue if you throw exceptions during processing, and the maximum delievery count is exceeded. If you want to explicitly move the message to the DLQ, you can do so as well. A common case for this is if you know that the message can never succeed because of its contents.
You cannot send new messages directly to the DLQ, because then you would have two messages in the system. You need to call a special operation on the parent entity. Also, <topic path>/$deadletterqueue does not work, because this would be the DLQ of all subscriptions. The correct entity path is built like this:
<queue path>/$deadletterqueue
<topic path>/Subscriptions/<subscription path>/$deadletterqueue
https://github.com/Azure/azure-service-bus/blob/master/samples/Java/azure-servicebus/DeadletterQueue/src/main/java/com/microsoft/azure/servicebus/samples/deadletterqueue/DeadletterQueue.java
This sample code is for queues, but you should be able to adapt it to topics quite easily:
// register the RegisterMessageHandler callback
receiver.registerMessageHandler(
new IMessageHandler() {
// callback invoked when the message handler loop has obtained a message
public CompletableFuture<Void> onMessageAsync(IMessage message) {
// receives message is passed to callback
if (message.getLabel() != null &&
message.getContentType() != null &&
message.getLabel().contentEquals("Scientist") &&
message.getContentType().contentEquals("application/json")) {
// ...
} else {
return receiver.deadLetterAsync(message.getLockToken());
}
return receiver.completeAsync(message.getLockToken());
}
// callback invoked when the message handler has an exception to report
public void notifyException(Throwable throwable, ExceptionPhase exceptionPhase) {
System.out.printf(exceptionPhase + "-" + throwable.getMessage());
}
},
// 1 concurrent call, messages are auto-completed, auto-renew duration
new MessageHandlerOptions(1, false, Duration.ofMinutes(1)),
executorService);
I would like to know how my Selenium framework can dequeue a message sitting in a message queue. I have built an application to send a JSON string containing k/v pairs to a message queue.
My architecture is as follows and separate apps:
A JSP Web Application exists accepting parameters resulting in a JSON string
A message sender exists and takes the JSON string and publishes it to a Queue
A message consumer exists and consumes the Messages. Its basically just sitting here
A Selenium Java Framework exists, but I would like to process the messages and for each message it will interpret the k/v pairs and kicks off the script.
I would like to use the messages already in the queue and process these messages within the selenium framework, how can I achieve this?
I will appreciate the help. I have edited the question with the code
This is the code snippet to send the JSON Message
public class MessageSender {
public static void main(String[] args) throws IOException {
SingleNumberLogin generateLogin = new SingleNumberLogin();
//function call to build the JSON object
String jsonQueue = generateLogin.buildJASONObject();
ConnectionFactory conFactory = new ConnectionFactory();
try {
Connection connInterface = conFactory.newConnection();
Channel mqChannel = connInterface.createChannel();
mqChannel.queueDeclare("MyQueue",false,false,false,null);
//Just assigning json to another string, then publish the message
String myMessage = jsonQueue;
mqChannel.basicPublish("","MyQueue",false ,false, null,myMessage.getBytes());
}catch (
IOException | TimeoutException e)
{
System.out.println(e.getStackTrace());
}
conFactory.setUsername("guest");
conFactory.setPassword("guest");
conFactory.setVirtualHost("/");
conFactory.setHost("localhost");
conFactory.setPort(5672);
}
}
code snippet for consumer code that I have inserted into the startup function of the automation script, so if a message arrives a single test case is executed
#BeforeTest
public static void initializeTestBaseSetup() throws Exception, IOException, TimeoutException {
ConnectionFactory conFactory = new ConnectionFactory();
Connection connInterface = conFactory.newConnection();
Channel mqChannel = connInterface.createChannel();
mqChannel.queueDeclare("MyQueue",false,false,false,null);
mqChannel.basicConsume("MyQueue", true, (consumerTag, message) -> {
//convert to byte array
String m = new String (message.getBody(), "UTF-8");
System.out.println("Message received" + m);
}, consumerTag -> {
});
}
Output JSON
JSON Message received 2020-08-28T20:39:30.845{
"NUMBER": "0000011111",
"Type": "BAU",
"User": "MyUser ",
"Email": "riidonesh#gmail.com",
}
When tested in isolation, it works perfectly fine, what I mean is that I send the message and check that the consumer receives it, adding the consumer code to my framework is where i am stuck.
I would suggest you don't think about what you have as a "selenium framework" - think of it as a "java framework".
Selenium is a set of libraries that allow you automate the web browser at a GUI level. The framework is the coded solution to facilitate creation and management of your test suite - it doesn't have to be limited to selenium and chances that's already just one of its components.
Trying to answer your question directly:
SELENIUM cannot read messages
JAVA can read messages
If your rabbitmq has a web front end then you may be able to use selenium for it, but this isn't a very efficient or a logical solution.
What you might want to consider, and what i would do, is extending your framework to use the rabbitmq libraries to process messages as you need. These libraries are designed for this task.
You say:
I would like to process the messages and for each message it will
interpret the k/v pairs and kicks off the script.
I understand this to mean that the messages are the pre-req data for the tests. If you want to read the values of a message before the test you can either:
Place the get/read in a generic #Before method
or if it's a specific message per test case, add it into the start of the test.
You're working in java so you can do whatever you want really.
To get you started, the rabbitmq tutorial starts here.
This is there hello world example for reading messages from the queue:
public class Recv {
private final static String QUEUE_NAME = "hello";
public static void main(String[] argv) throws Exception {
ConnectionFactory factory = new ConnectionFactory();
factory.setHost("localhost");
Connection connection = factory.newConnection();
Channel channel = connection.createChannel();
channel.queueDeclare(QUEUE_NAME, false, false, false, null);
System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
}
}
I try to implement a queue browser for ActiveMQ.
The code shown below should display the text messages in the queue named 'Q1'. There are two messages in there. In general it works but the last e.hasMoreElements() call needs up to 20 seconds. I wanted to update the list every 500 millis. Why is that so slow?When i press 'update' in the browser view for http://localhost:8161/admin/browse.jsp?JMSDestination=Q1 e.hasMoreElements() returns immediately. What's going on here? How to achieve a 'realtime' view?
//init:
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
Connection connection = connectionFactory.createConnection();
connection.start();
Session session = connection.createSession(true, Session.CLIENT_ACKNOWLEDGE);
Queue queue = session.createQueue("Q1");
boolean run = true;
while (run) {
LOG.info("--------------------------------------------------------------------------------");
QueueBrowser browser = session.createBrowser(queue);
Enumeration e = browser.getEnumeration();
while (e.hasMoreElements()) { //<- very slow before returning false after last message. why?
Object o = e.nextElement();
if (o instanceof ActiveMQTextMessage) {
LOG.info(((ActiveMQTextMessage) o).getText());
} else {
LOG.info(o.toString());
}
}
Thread.sleep(500);
browser.close();
}
session.close();
connection.close();
After my previous comment, I've discovered that calling setTransactedIndividualAck(true) on the connection factory solves the problem
ActiveMQConnectionFactory cf2 = new ActiveMQConnectionFactory(...);
cf2.setTransactedIndividualAck(true);
I'm not sure that this is the right thing to do for the problem but at least it works now. See the message on the ActiveMQ user forum here:
http://activemq.2283324.n4.nabble.com/JMS-browser-getEnumeration-hasMoreElements-takes-15s-on-last-element-td4709969.html
I had the same issue. But changing the acknowledgment on the session eliminated the delay.
Try this:
Session session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
I found that calling Session.commit() within my hasMoreElements() loop stopped the hanging using activemq-broker version 5.14.5:
while(enumeration.hasMoreElements()) {
final Message message = (Message)enumeration.nextElement();
final TextMessage textMessage = (TextMessage)message;
session.commit();
}
I did more research to see if this was a bug with ActiveMQ or not and found that activemq-broker version 5.15.1 did not hang, even without calling commit() after each iteration. All prior versions of the broker hanged on the final call to hasMoreElements(). It doesn't seem like the contributors deliberately fixed this particular issue, since the bug report on JIRA that the change referenced was for something different. The change that fixed this issue changed part of the iterate() method of the org.apache.activemq.broker.region.Queue class from:
// are we done browsing? no new messages paged
if (!added || browser.atMax()) {
browser.decrementQueueRef();
browserDispatches.remove(browserDispatch);
}
to
// are we done browsing? no new messages paged
if (!added || browser.atMax()) {
browser.decrementQueueRef();
browserDispatches.remove(browserDispatch);
} else {
wakeup();
}
To confirm this was the change that fixed the issue, I went to the previous version, 5.15.0 and forced wakeup() to be called using a debugger and the call to hasMoreElements() did not hang.
After some research and try i switched to the more up-to-date JMX technology. There are no performance issues while walking through the queues.
Some code:
JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi");
JMXConnector connector = JMXConnectorFactory.connect(url, null);
connector.connect();
connection = connector.getMBeanServerConnection();
ObjectName name = new ObjectName(getObjectNameByBrokerName(brokerName));
brokerMBean = (BrokerViewMBean) MBeanServerInvocationHandler.newProxyInstance(connection, name, BrokerViewMBean.class, true);
ObjectName[] objNames = brokerMBean.getQueues();
for (ObjectName objName : objNames) {
QueueViewMBean queueMBean = (QueueViewMBean) MBeanServerInvocationHandler.newProxyInstance(connection, objName, QueueViewMBean.class, true);
System.out.println(queueMBean.getName());
}
You have to activate jmx in the configuration. It's de-activated by default.
Given the following publisher in node.js and the following subscriber in java (this setup is fully functional) I have the following two questions:
What should I use as the third argument in queueBind and why? Why does it works as is ("test" is a random pick)?
Is there a way to specify queue in addition to exchange in rabbit.js? If yes then how? If not then why and which module should I use instead (code example would be welcome)?
// node.js
var context = require("rabbit.js").createContext();
var pub = context.socket('PUB');
pub.connect(config.exchange);
server.post("/message/:msg", function(req, res) {
pub.write(req.params.msg, 'utf8');
res.end();
});
// java
ConnectionFactory factory = new ConnectionFactory();
factory.setHost(host);
try {
Connection connection = factory.newConnection();
Channel channel = connection.createChannel();
channel.exchangeDeclare(exchange, "fanout");
String queueName = channel.queueDeclare().getQueue();
channel.queueBind(queueName, exchange, "test"); // Question1: what should I use as the third argument and why?
// Question2: is there a way to configure rabbit.js with a queue name instead?
//channel.queueDeclare(queueName, false, false, false, null);
QueueingConsumer consumer = new QueueingConsumer(channel);
channel.basicConsume(queueName, true, consumer);
try {
while (true) {
QueueingConsumer.Delivery delivery = consumer.nextDelivery();
String message = new String(delivery.getBody());
LOG.info("Received message: " + message);
}
} catch (InterruptedException e) {
LOG.catching(e);
} finally {
channel.close();
connection.close();
}
} catch (IOException e) {
LOG.catching(e);
}
Own answer, what I've digged up so far:
The third argument, the routing key, is what is known as topic in rabbit.js. By supplying test I am only subscribing to messages send to the test topic or without a topic set (default in rabbit.js). If I were to use topic in the publisher as well, I could use pub.publish(topic, message, encoding) instead of pub.write(message, encoding) or supply it to the connect method
Does not look so and still do not know why really. The argument goes that rabbit.js is a higher-level library and it, therefore, makes certain simplifications. Why exactly this simplification is made I do not know. However, I primarily wanted to use a single exchange for multiple communication threads, which I can also achieve by using topics/routing keys. So not a big deal.
i am new to JMS and going thru the example of Active MQ Hello world. Say i have a scenario whenever i make entry
under employee table in DB, i have to put the message in queue.here is the producer code snippet from hello world example
public static class HelloWorldProducer {
public void createMessageOnQueue() {
try {
// Create a ConnectionFactory
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("vm://localhost");
// Create a Connection
Connection connection = connectionFactory.createConnection();
connection.start();
// Create a Session
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
// Create the destination (Topic or Queue)
Destination destination = session.createQueue("TEST.FOO");
// Create a MessageProducer from the Session to the Topic or Queue
MessageProducer producer = session.createProducer(destination);
producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
// Create a messages
String text = "Hello world! From: " + Thread.currentThread().getName() + " : " + this.hashCode();
TextMessage message = session.createTextMessage(text);
// Tell the producer to send the message
System.out.println("Sent message: "+ message.hashCode() + " : " + Thread.currentThread().getName());
producer.send(message);
// Clean up
session.close();
connection.close();
}
catch (Exception e) {
System.out.println("Caught: " + e);
e.printStackTrace();
}
}
}
Now my question is if i close the connection and session, will it close the queue also? If yes,what will happen if message has not been consumed yet?
Second question is if i need to publish the message on same queue(i.e "TEST.FOO") second time , do i need to call createMessageOnQueue method second time. If yes, will it not create new queue with session.createQueue("TEST.FOO")?
Now my question is if i close the connection and session, will it
close the queue also? If yes,what will happen if message has not been
consumed yet?
message will still be on queue. No such thing as 'closing a queue'.
Second question is if i need to publish the message on same queue(i.e
"TEST.FOO") second time , do i need to call createMessageOnQueue
method second time. If yes, will it not create new queue with
session.createQueue("TEST.FOO")?
session.createQueue("TEST.FOO") does not necessarily create queue, it just get a reference to existing queue.
javadoc of session#createQueue()
Note that this method simply creates an object that encapsulates the
name of a topic. It does not create the physical topic in the JMS
provider. JMS does not provide a method to create the physical topic,
since this would be specific to a given JMS provider. Creating a
physical topic is provider-specific and is typically an administrative
task performed by an administrator, though some providers may create
them automatically when needed.
The queue is created once and only you can delete it manually.
Once the message is sent to a queue, it will wait on the queue until it's consumed (unlike topics).
You don't need to re-create the message if you want to send it twice. But then again, why would you send it two times?
I feel that your problem might be solved using JMS transactions.