Develop Reference

How to use MaxReconnectAttemps in ActiveMQ

I'm having an issue with ActiveMQ, I'm trying to connect using MaxReconnectAttemps but its seems to ignore the property. I'm putting an invalid destination so it tries to connect twice but it seems to be trying to connect indefinitely.
Any ideas as to set it up?
Thanks,
IConnectionFactory factory = new ConnectionFactory(("failover://(tcp://localhost:61616)?initialReconnectDelay=2000&maxReconnectAttempts=2"));
using (Connection connection = factory.CreateConnection(username,password) as Connection)
{
connection.ClientId = "ClientId";
using (ISession session = connection.CreateSession())
{
IQueue queue = session.GetQueue(queueName);
var producer = session.CreateProducer(queue);
producer.DeliveryMode = MsgDeliveryMode.Persistent;
ITextMessage request = session.CreateTextMessage("Hello World!");
producer.Send(request);
}
}

Since you are using the .NET client you need to use a prefix on the URI options for the failover transport, so to configure maxReconnectAttempts you need to pass the option like this:
failover:(tcp://localhost:61616)?transport.maxReconnectAttempts=3
It's a good idea to look at the documentation for the client you are using which is here.

Creating a new Queue Manager and Queue in Websphere MQ (using C#)

I'm writing an application that uses WebSphere MQ for messaging. For my unittests (flowtests), I want to verify that I have put the right messages on the response queue.
I'm trying to figure out how to do this. My main obstacle is that I think it might be scary to clear a queue before I run my unittest, because the same queue might be used by another application.
I thought a decent workaround would be to create a new queue manager and queue for my unittest and delete it after using it.
So my question is: Is it possible to create a queue manager and queue using C#?

For future reference and future people who want to create queues. I figured out how to create and delete IBM MQ queues (not queuemanagers) with PCF messaging. It is not very straightforward, but it can be done.
We have implemented it in a library and are using it to create and delete queues before and after integration tests respectivally. The most important part of code in this library is shown in the code sample below. Just add a reference to amqmdnet.dll and below code will create a queue and delete it.
string queueManagerName = "QM_LOCAL";
string queueName = "DeleteMeQueue";
Hashtable options = new Hashtable();
// This is a connection to a local server. For a remote server use 'TRANSPORT_MQSERIES_CLIENT', 'TRANSPORT_MQSERIES_XACLIENT' or 'TRANSPORT_MQSERIES_MANAGED'
options.Add(IBM.WMQ.MQC.TRANSPORT_PROPERTY, "TRANSPORT_MQSERIES_BINDINGS");
// For 'TRANSPORT_MQSERIES_CLIENT', 'TRANSPORT_MQSERIES_XACLIENT' or 'TRANSPORT_MQSERIES_MANAGED' uncomment the below
// string hostName = "RemoteServerName";
// string channelName = "SYSTEM.ADMIN.SVRCONN";
// int portNumber = 1414;
// options.Add(IBM.WMQ.MQC.HOST_NAME_PROPERTY, hostName);
// options.Add(IBM.WMQ.MQC.CHANNEL_PROPERTY, channelName);
// options.Add(IBM.WMQ.MQC.PORT_PROPERTY, portNumber);
// options.Add(IBM.WMQ.MQC.CONNECT_OPTIONS_PROPERTY, IBM.WMQ.MQC.MQC.MQCNO_STANDARD_BINDING);
IBM.WMQ.MQQueueManager queueManager = null;
IBM.WMQ.PCF.PCFMessageAgent agent = null;
try
{
// Initialize a connection to the (remote) queuemanager and a PCF message agent.
queueManager = new IBM.WMQ.MQQueueManager(queueManagerName, options);
agent = new IBM.WMQ.PCF.PCFMessageAgent(queueManager);
// Create queue
IBM.WMQ.PCF.PCFMessage createRequest = new IBM.WMQ.PCF.PCFMessage(IBM.WMQ.PCF.CMQCFC.MQCMD_CREATE_Q);
createRequest.AddParameter(IBM.WMQ.MQC.MQCA_Q_NAME, queueName);
createRequest.AddParameter(IBM.WMQ.MQC.MQIA_Q_TYPE, IBM.WMQ.MQC.MQQT_LOCAL);
createRequest.AddParameter(IBM.WMQ.MQC.MQIA_DEF_PERSISTENCE, IBM.WMQ.MQC.MQPER_PERSISTENT);
createRequest.AddParameter(IBM.WMQ.MQC.MQCA_Q_DESC, "Created by " + Environment.UserName + " on " + DateTime.UtcNow.ToString("o"));
IBM.WMQ.PCF.PCFMessage[] createResponses = agent.Send(createRequest);
// Delete queue
IBM.WMQ.PCF.PCFMessage deleteRequest = new IBM.WMQ.PCF.PCFMessage(IBM.WMQ.PCF.CMQCFC.MQCMD_DELETE_Q);
deleteRequest.AddParameter(IBM.WMQ.MQC.MQCA_Q_NAME, queueName);
IBM.WMQ.PCF.PCFMessage[] deleteResponses = agent.Send(deleteRequest);
}
finally
{
// Disconnect the agent and queuemanager.
if (agent != null) agent.Disconnect();
if (queueManager != null && queueManager.IsConnected) queueManager.Disconnect();
}

Creation of queue manager and queues are administrative jobs. Creation of queue manager can not be done using an user defined application. You have to use the command crtmqm <qmname> provided by MQ to create queue manager.
I would suggest you ask your queue manager administrator to create dedicated queue for you. Only your unit test use this queue and no other user is allowed to put/get messages to this queue.

How to handle Errors and Connection Close using WampSharp

I have been working with WampSharp, i.e the client library provided to connect with autobahn wamp websocket.
I have successfully connected with the Autobahn Wamp Websocket I created in python using a .Net client application using the following code(using WampSharp):
DefaultWampChannelFactory channelFactory = new DefaultWampChannelFactory();
channel = channelFactory.CreateChannel(serverAddress);
channel.Open();
here serverAddress is: 127.0.0.1:8000 (i.e. my websocket starts at 8000 port no. of my local machine).
I am using the pubsub mechanism for exchange of data provided by autobahn wamp websocket using following code:
public void Subscribe()
{
ISubject<string> subscribe1 = channel.GetSubject<string>(#"simple/topicSubject1");
IDisposable subject1 = subscribe1.Subscribe(msg => MessageRecieved(msg));
}
public void Publish()
{
ISubject<string> subjectForPublish = channel.GetSubject<string>(#"simple/topicSubject1");
subjectForPublish.OnNext(sd.SerializeObject(DataToPublish));
}
These all processes are done successfully.
The issue I am facing is that I cannot find any handlers to handle the errors and loss of connection as we do in traditional websocket.
In traditional websocket we have handlers like:
webSocket.Error += new EventHandler<SuperSocket.ClientEngine.ErrorEventArgs>(webSocket_Error);
webSocket.Closed += new EventHandler(webSocket_Closed);
I need to achieve the above functionality using wampsharp.
Thanks in advance.

Try this:
DefaultWampChannelFactory factory = new DefaultWampChannelFactory();
IWampChannel<JToken> channel = factory.CreateChannel("ws://localhost:9090/ws");
IWampClientConnectionMonitor monitor = channel.GetMonitor();
monitor.ConnectionError += ConnectionError;
monitor.ConnectionEstablished += ConnectionEstablished;
monitor.ConnectionLost += ConnectionLost;
await channel.OpenAsync();

ActiveMQ NMS Temporary Queue not destroyed when Connection is closed

I've read in the Active MQ documentation that Temporary Queues are deleted by the broker when the connection that was used to create them is closed.
I'm using Apache NMS v1.5.0 and Active MQ 5.1.3, and temporary queues are always persisting even after the connection has gone out of scope.
I have a client / server scenario, whereby the client creates a temp queue and creates a message, specifying the temp queue in the ReplyTo property of the message.
The server component then reads the message and starts sending messages to the reply to queue.
Unfortunately, when the client closes it's connection, the temporary queue it created does not get deleted.
The following code snippet should illustrate what i mean.
I create one connection, and create a temporary queue using that connection.
I close the connection and create a second one.
I should not be able to produce and consume messages on the temporary queue using a session
created by the second connection, and yet i can.
Can someone tell me if i'm doing something wrong here. How can i get Active MQ to delete the Temporary Queue.
Any help much appreciated.
[Test]
public void TempQueueTest()
{
var cf = new ConnectionFactory("tcp://activemq-broker:61616");
using (var connection = cf.CreateConnection())
{
connection.Start();
using (var session = connection.CreateSession())
{
var normalQueue = session.GetQueue("normalQueue");
ITemporaryQueue tempQueue = session.CreateTemporaryQueue();
using (var producer = session.CreateProducer(normalQueue))
{
// create a messasge and put on a normal queue
//specify the temp queue as the reply to queue
var mesage = new ActiveMQTextMessage("hello");
mesage.ReplyTo = tempQueue as ActiveMQDestination;
producer.Send(mesage);
}
}
connection.Stop();
}
// ok, connection has been disposed, so the temp queue should be destroyed
// create a new connection
using (var connection = cf.CreateConnection())
{
connection.Start();
using (var session = connection.CreateSession())
{
var normalQueue = session.GetQueue("normalQueue");
using (var consumer = session.CreateConsumer(normalQueue))
{
var message = consumer.Receive() as ActiveMQTextMessage;
// replyToDest is the temp queue created with the previous connection
var replyToDest = message.ReplyTo;
using (var producer = session.CreateProducer(replyToDest))
{
// i shouldn't be able to send a message to this temp queue
producer.Send(new ActiveMQTextMessage("this shouldn't work"));
}
using (var tempConsumer = session.CreateConsumer(replyToDest))
{
// is shouldn't be able to receive messages on the temp queue as it should be destroyed
var message1 = tempConsumer.Receive() as ActiveMQTextMessage;
}
}
}
connection.Stop();
}
}

Given the ancient versions you are using I don't know there's any way fix what's going on here. The code looks correct but there were a large number of fixes between the v1.5.0 release of the NMS libs and the current 1.6.0 many of which fixed issues with Temp Destinations. I'd suggest you try and move on to later versions to see if your problem goes away.
Right now you'd probably have to use JMX to access the broker and remove old temp destinations.

RabbitMQ C# client not talking to Apache Qpid Java Broker

I've installed the M4 release of the Apache Qpid Java broker on a Windows box, and started it using the out-of-the-box configuration (via the qpid-server.bat script).
I'm now trying to publish a message to a queue using the RabbitMQ C# client library (version 1.5.3, compiled for .NET 3.0); my code is:
public void PublishMessage(string message)
{
ConnectionFactory factory = new ConnectionFactory();
factory.Parameters.VirtualHost = "...";
IProtocol protocol = Protocols.FromEnvironment();
using (IConnection conn = factory.CreateConnection(protocol, "localhost", 5672))
{
using (IModel ch = conn.CreateModel())
{
string exchange = "...";
string routingKey = "...";
ch.BasicPublish(exchange, routingKey, null, Encoding.UTF8.GetBytes(message));
}
}
}
Basically, I'm unsure what values to use for factory.Parameters.VirtualHost and the strings exchange and routingKey. I've tried various combinations, but nothing seems to work - the closest I've got is seeing the following in the Qpid server log:
2009-03-19 17:11:04,248 WARN [pool-1-thread-1] queue.IncomingMessage (IncomingMessage.java:198) - MESSAGE DISCARDED: No routes for message - Message[(HC:896033 ID:1 Ref:1)]: 1; ref count: 1
which looks as though the Qpid server is receiving the message, but doesn't know what to do with it.
Any advice on what configuration values I need in my client code (bearing in mind I'm using the default Qpid config in virtualhosts.xml) would be much appreciated. More general information on virtual hosts, exchanges, queues and routing keys, and how Qpid links them all together, would also be very useful.
Thank you in advance,
Alan

Just for reference, I managed to get this working in the end. The code below sends a message to the queue test-queue in the test.direct exchange on the localhost virtual host (all part of the default Qpid broker configuration):
public void PublishMessage(string message)
{
ConnectionFactory factory = new ConnectionFactory();
factory.Parameters.VirtualHost = "/localhost";
IProtocol protocol = Protocols.AMQP_0_8_QPID;
using (IConnection conn = factory.CreateConnection(protocol, "localhost", 5672))
{
using (IModel ch = conn.CreateModel())
{
ch.ExchangeDeclare("test.direct", "direct");
ch.QueueDeclare("test-queue");
ch.QueueBind("test-queue", "test.direct", "TEST", false, null);
ch.BasicPublish("test.direct", "TEST", null, Encoding.UTF8.GetBytes(message));
}
}
}