I am using IBM MQ to produce messages while receiving it through a consumer on my client. To create the connection I'm using JmsConnectionFactory, along with provided properties to set up the connection with the server. So from what I understand is, as the consumer the only way to recognize the messages produced by the server is through the onMessage call. I'm currently testing this by creating a local producer and local consumer and assuring that every message sent by the producer is received by the consumer.
I'm running into the following problems:
I'm not receiving all messages produced.
Depending on the size of the message, more of them are received if they are smaller.
Here is code for the creation of the producer:
JmsConnectionFactory cf = ff.createConnectionFactory();
cf.setStringProperty(WMQConstants.WMQ_HOST_NAME, qm.getHost());
int port = ###;
cf.setIntProperty(WMQConstants.WMQ_PORT, port);
cf.setStringProperty(WMQConstants.WMQ_CHANNEL, qm.getChannel());
cf.setIntProperty(WMQConstants.WMQ_CONNECTION_MODE, WMQConstants.WMQ_CM_CLIENT);
cf.setStringProperty(WMQConstants.WMQ_QUEUE_MANAGER, qm.getQueueManagerName());
Connection connection = cf.createConnection(qm.getUser().getUsername(), qm.getUser().getPassword());
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Destination destination = session.createQueue(qm.getDestinationName());
LOG.debug("Destination Created at " +qm.getDestinationName());
msgSender = session.createProducer(destination);
msgSender.setDeliveryMode(DeliveryMode.PERSISTENT);
And this is how the producer is sending messages:
/**
* msgSender is the MessageProducer object
**/
private void produceMessages(int numOfMessages) throws JMSException, InterruptedException {
for (int i = 0; i < numOfMessages; i++) {
String text = "Message #" +i;
TextMessage message = session.createTextMessage(text);
msgSender.send(message);
}
}
On the consumer side, I am simply printing received messages and verifying visually:
#Override
public void onMessage(Message m) {
System.out.println(((TextMessage)m).getText());
}
I am not fully familiar with how IBM MQ works. Could the reason for the missing messages reside on the MQ simply ignoring messages that are produced before a message is fully sent?
I would say the issue is residing on your consumer side, rather than your simulated producer. Your message producer should be sending messages to MQ just fine, but multiple consumers are probably competing to retrieve these messages from the connection you have set up (given the same queue manager properties). So unless no one else is trying to consume from your IBM MQ, you're going to be expected to miss some messages.
You should use other method of send(Message m, CompletionListener l) to send new messages only after completion.
And if you use "Best Effort", it still will lose messages. You can try "Express" instead.
Related
I am using RMQ and it's JMS client to publish messages to RMQ (this is a requirement i have, I can't use their java client instead of JMS client).
So, basically I do this:
RMQConnectionFactory factory = new RMQConnectionFactory() ;
factory.setUsername(props.getProperty("rmq.username"));
factory.setPassword(props.getProperty("rmq.password"));
factory.setHost(props.getProperty("rmq.host"));
factory.setVirtualHost(props.getProperty("rmq.virtualHost"));
factory.setPort(Integer.parseInt(props.getProperty("rmq.port")));
Connection connection = factory.createConnection();
connection.start();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
String queueName = managerProps.getProperty("rmq.queue.name");
Queue queue = session.createQueue(queueName);
producer = session.createProducer(queue);
TextMessage msg = session.createTextMessage(text);
msg.setText(text);
producer.send(msg);
I have a policy set up on RMQ overflow: reject-publish, so if it's over the limit RMQ is supposed to send a nack when the queue is full, but I don't seem to get it.
The question is - how do I determine if the message was rejected? I assume the producer.send(msg) to be synchronous and throw exception if the message is not published, but I don't get any exceptions, it just looks like everything got published.
JMS spec has a send(msg, CompletionListener) with a listener with two methods onCompletion and onException, but it doesn't look like RMQ JMS client implemented this method.
Is there another way to make sure that message made it through?
RabbitMQ use Publisher Confirms to guarantee that a message isn't lost, so if your Queue overflow behavior is reject-publish, the confirm channel will got a nack. It is also contains in many AMQP client.
But in JMS client, I have check the code in rabbitmq-jms-client, and no send implementaion contains CompletionListener. So if you want to enjoy reliable publish, please use AMQP client.
I did some digging, the CompletionListener is part of JMS 2.0 and RMQ only implements JMS 1.1, that's the reason it's not there.
But it looks like I can do something with transactions. I would need to change the code like this:
RMQConnectionFactory factory = new RMQConnectionFactory() ;
// ... skipping the code here
connection.start();
// set session to be transacted
session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
String queueName = managerProps.getProperty("rmq.queue.name");
Queue queue = session.createQueue(queueName);
producer = session.createProducer(queue);
TextMessage msg = session.createTextMessage(text);
msg.setText(text);
producer.send(msg);
// commit transaction
session.commit();
This will work if the queue is not full, but will throw an exception after a rejected message with this:
Caused by: com.rabbitmq.client.ShutdownSignalException: channel error; protocol method: #method(reply-code=406, reply-text=PRECONDITION_FAILED - partial tx completion, class-id=90, method-id=20)
I can then catch the exception and do what I need to do to resend/save the message.
After I went to multiple sites and learned JMS I wrote a JMS standalone client to read messages from a database and send them one by one. I also want to receive message one by one message and then update the database.
I need to send a message to a queue and the other application using standard JMS which will consume a TextMessage and whose body will be read as an ISO-8859-1 string. Also they will similarly send reply as a TextMessage.
I wrote a for loop to read the message one by one from the DB.
I am new to JMS so could you please correct me whether my below code works properly to read and send messages to a queue and receive and update the DB. Is there any thing I need to change in the JMS Type or any thing I need to correct. Does the for loop work fine?
/*MQ Configuration*/
MQQueueConnectionFactory mqQueueConnectionFactory = new MQQueueConnectionFactory();
mqQueueConnectionFactory.setHostName(url);
mqQueueConnectionFactory.setChannel(channel);//communications link
mqQueueConnectionFactory.setPort(port);
mqQueueConnectionFactory.setQueueManager(qmgr);//service provider
mqQueueConnectionFactory.setTransportType(JMSC.MQJMS_TP_CLIENT_MQ_TCPIP);
/*Create Connection */
QueueConnection queueConnection = mqQueueConnectionFactory.createQueueConnection();
queueConnection.start();
/*Create session */
QueueSession queueSession = queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
/*Create response queue */
// Queue queue = queueSession.createQueue("QUEUE.RESPONSE");
int messageCount = 0;
Queue queue = queueSession.createQueue(replytoQueueName);
QueueSender queueSender = null;
QueueReceiver queueReceiver=null;
for (Testbean testBean : testbeanList) {
String testMessage = testBean.getMessage();
/*Create text message */
textMessage = queueSession.createTextMessage(testMessage);
logger.info("Text messages sent: " + messageCount);
textMessage.setJMSReplyTo(queue);
textMessage.setJMSType("mcd://xmlns");//message type
textMessage.setJMSExpiration(2*1000);//message expiration
textMessage.setJMSDeliveryMode(DeliveryMode.PERSISTENT); //message delivery mode either persistent or non-persistemnt
/*Create sender queue */
// QueueSender queueSender = queueSession.createSender(queueSession.createQueue("QUEUE.REQEST"));
queueSender = queueSession.createSender(queueSession.createQueue(outputQName));
queueSender.setTimeToLive(2*1000);
queueSender.send(textMessage);
/*After sending a message we get message id */
System.out.println("after sending a message we get message id "+ textMessage.getJMSMessageID());
String jmsCorrelationID = " JMSCorrelationID = '" + textMessage.getJMSMessageID() + "'";
/*Within the session we have to create queue reciver */
queueReceiver = queueSession.createReceiver(queue,jmsCorrelationID);
/*Receive the message from*/
Message message = queueReceiver.receive(60*1000);
// String responseMsg = ((TextMessage) message).getText();
byte[] by = ((TextMessage) message).getText().getBytes("ISO-8859-1");
logger.info(new String(by));
String responseMsg = new String(by,"UTF-8");
testDAO rmdao = new testDAO();
rmdao.updateTest(responseMsg, jmsCorrelationID);
messageCount += 1;
}
queueSender.close();
queueReceiver.close();
queueSession.close();
queueConnection.close();
Couple of things:
I would create your QueueSender and the Queue object its sending messages to outside the for loop since they don't appear to be changing.
Without the corresponding consumer code it's ultimately impossible to tell if the selector will work or not, but not invoking setCorrelationID() on the message you send looks a bit strange to me. Using the provider-assigned message ID may be a common pattern with IBM MQ request/reply applications, but the general pattern for using a correlation ID is to invoke setJMSCorrelationID() on the sent message. This makes the code more clear and also allows the application to directly control the uniqueness of the correlation ID. This is potentially important for application portability (e.g. if you migrated from IBM MQ to a different JMS provider) since different JMS providers use styles/formats of message ID specific to their particular implementation. Also, regarding the message ID the JMS spec states, "The exact scope of uniqueness is provider defined," which in my opinion is not a strong enough guarantee of uniqueness especially when using something like java.util.UUID.randomUUID().toString() is so simple.
You should ensure that you're using an XA transaction for both the JMS & database work so that they are atomic.
Close your JMS resources in a finally block.
I am using the latest ActiveMQ with persistence and I have implemented already the producer and consumer which are working as intended. However I cannot get to producer to resend messages when the consumer is back from downtime. It only starts sending messages produces after the consumer is back up.
Producer
private void someInitFunction(){
connection = factory.createConnection();
connection.start();
session = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
destination = session.createQueue(queueName);
producer = session.createProducer(destination);
producer.setDeliveryMode(DeliveryMode.PERSISTENT);
}
private void onNewMessage(Serialized data){
try{
ObjectMessage message = createObjectMessage();
message.setObject(data);
producer.send(message);
} catch(Exception e){ log.error("consumer not available");}
}
What I want to achieve is to make the producer re-send the messages that failed to deliver while the consumer is down. So as an example: producer sends message 1,2 and consumer receives them but then it goes offline. Producer sends 3,4 while consumer is offline and the messages should be stored until consumer becomes available and 3,4 are resent for the consumer to receive.
I have read http://activemq.apache.org/how-do-durable-queues-and-topics-work.html and enabled durable queue using DeliveryMode.PERSISTENT but messages are not resent on-reconnect.
Any Ideas ?
I'm learning how to use ActiveMQ and now we are facing the following problem.
Suppose that I have a topic named topic.test on ActiveMQ which have two subscribers.
In a given moment, I have only one of those subscribers waiting for messages, and a producer send a message for the topic I mentioned above.
Ok, the connected subscriber get the message, but shouldn't the other subscriber receive that message later when it is connected? Well, in my case it's not happening: my subscribers are only receiving messages while connected. All the other messages, which were sent while they were not connected are not being received by them. What could I be doing wrong?
Here is some of the source code I wrote to test ActiveMQ. Maybe you could find what is wrong with it.
My consummer code:
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
Connection connection = connectionFactory.createConnection();
connection.setClientID("leitorTeste");
conexao.start();
Session sessao = conexao.createSession(false, Session.AUTO_ACKNOWLEDGE);
Topic fonte = sessao.createTopic("topic.test");
MessageConsumer consumer = sessao.createConsumer(fonte);
javax.jms.Message presente = null;
while ((presente = consumer.receive()) != null) {
System.out.println(((TextMessage) presente).getText());
}
consumer.setMessageListener(new LeitorMensagens());
conexao.close();
And here is my producer code:
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
Connection connection = connectionFactory.createConnection();
Session sessao = conexao.createSession(true, Session.AUTO_ACKNOWLEDGE);
connection.start();
Destination destino = sessao.createTopic("topic.test");
MessageProducer produtorMensagem = sessao.createProducer(destino);
produtorMensagem.setDeliveryMode(DeliveryMode.PERSISTENT);
TextMessage message = sessao.createTextMessage("Hi!");
produtorMensagem.send(message);
sessao.commit();
connection.close();
Is there any other configuration I should add to ActiveMQ so that my consumers could get older messages?
You must make your consumers "permanent". Otherwise, AMQ "forgets" about them as soon as they unsubscribe. To do this, use Session.createDurableSubscriber()
There is something called a retroactive consumer policy you can also set on the broker. This is for Topic Subscribers - which aren't durable, but may wish to receive 'recent' messages they may have missed - see also Subscription Recovery Policy
I'm using ActiveMQ on a simulation of overloading servers in Java. And mainly it goes ok, but when I get over 600 requests the thing just go WTF!
I think the bottleneck is my Master Server which is this guy below. I'm already reusing the connection and creating various sessions to consume messages from clients. Like I said, I'm using about 50-70 sessions per connection, reutilizing the connection and queue. Any idea of what I can reuse/optimize of my components/listener below?
The architecture is the follow:
* = various
Client ---> JMS MasterQueue ---> * Master ---> JMS SlavaQueue ---> * SlaveQueue
Mainly I'm creating a Temp Queue for each session of Master --> Slave communication, is that a big problem on performance?
/**
* This subclass implements the processing log of the Master JMS Server to
* propagate the message to the Server (Slave) JMS queue.
*
* #author Marcos Paulino Roriz Junior
*
*/
public class ReceiveRequests implements MessageListener {
public void onMessage(Message msg) {
try {
ObjectMessage objMsg = (ObjectMessage) msg;
// Saves the destination where the master should answer
Destination originReplyDestination = objMsg.getJMSReplyTo();
// Creates session and a sender to the slaves
BankQueue slaveQueue = getSlaveQueue();
QueueSession session = slaveQueue.getQueueConnection()
.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
QueueSender sender = session
.createSender(slaveQueue.getQueue());
// Creates a tempQueue for the slave tunnel the message to this
// master and also create a masterConsumer for this tempQueue.
TemporaryQueue tempDest = session.createTemporaryQueue();
MessageConsumer masterConsumer = session
.createConsumer(tempDest);
// Setting JMS Reply Destination to our tempQueue
msg.setJMSReplyTo(tempDest);
// Sending and waiting for answer
sender.send(msg);
Message msgReturned = masterConsumer.receive(getTimeout());
// Let's check if the timeout expired
while (msgReturned == null) {
sender.send(msg);
msgReturned = masterConsumer.receive(getTimeout());
}
// Sends answer to the client
MessageProducer producerToClient = session
.createProducer(originReplyDestination);
producerToClient.send(originReplyDestination, msgReturned);
} catch (JMSException e) {
logger.error("NO REPLY DESTINATION PROVIDED", e);
}
}
}
Well, After some reading I found out how to optimize.
We should reuse some session variables, such as the sender and tempqueue. Instead of creating new ones.
Another approach is put the stack size for thread in Java lower, following this link
ActiveMQ OutOfMemory Can't create more threads
It could have to do with the configuration of the listener thread pool. It could be that up to a certain threshold number of requests per second the listener is able to keep up and process the incoming requests in a timely way, but above that rate it starts to fall behind. it depends on the work done for each incoming request, the incoming request rate, the memory and CPU available to each listener, and the number of listeners allocated.
If this is true, you should be able to watch the queue and see when the number of incoming messages start to back up. That's the point at which you need to increase the resources and number of listeners to process efficiently.