activemq-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Timothy Bish <tabish...@gmail.com>
Subject Re: NMS - cannot recover from connection failure
Date Mon, 10 May 2010 23:58:07 GMT
On Tue, 2010-05-11 at 00:43 +0100, Tammer Salem wrote:
> Sorry - yes I get an exception stating that it cannot connect to the given
> URI (even though the URI is 100% correct in that block of code). When I shut
> down the client and restart it - it works fine.
> 

You could try doing an explicit close on all the NMS.Stomp resources
that you created, session, connection etc before recreating to see if
that frees up a resource that is preventing you from reconnecting to
that same URI.  

Regards
Tim.

> On 10 May 2010 21:31, Timothy Bish <tabish121@gmail.com> wrote:
> 
> > On Mon, 2010-05-10 at 15:04 +0100, Tammer Salem wrote:
> > > Hello All,
> > > I have an NMS client using the stomp broker on a .netcf device. For the
> > most
> > > part it works absolutely fine, but now I'm trying to harden the device
> > (for
> > > network failures etc.).
> > > I have added an exception listener and specifically look for IOExceptions
> > > (which I believe are what .NET throws if the GPRS/3G network connectivity
> > > dies). I can successfully capture this exception and then I fire off a
> > > thread to restart the connection and add my listeners again.
> > >
> > > At the moment this method doesn't seem to work - I can never get a
> > > connection again. Can anyone advise what is the best way of doing this?
> > >
> >
> > So what happens exactly when the code attempts to create the new
> > Connection object and restore the Sessions and Destinations etc?  Is
> > there an exception being thrown?
> >
> > Regards
> > Tim.
> >
> >
> > > I've also attached my code so that you know what I'm trying to do.
> > >
> > >     class AMQMessageHandler
> > >
> > >     {
> > >
> > >         private String myQueue;
> > >
> > >         private String connecturi;
> > >
> > >
> > >
> > >         //private ISession session;
> > >
> > >         IConnectionFactory factory;
> > >
> > >         IConnection connection;
> > >
> > >         ISession session;
> > >
> > >         IDestination destination;
> > >
> > >         IMessageConsumer messageConsumer;
> > >
> > >
> > >
> > >         /*
> > >
> > >          * the UI thread within whose context the code will be executed
> > >
> > >          */
> > >
> > >         private Form uiThread;
> > >
> > >
> > > >         /*
> > >
> > >          * function in the UI thread to handle exceptions
> > >
> > >          */
> > >
> > >         private Delegate exceptionDelegate;
> > >
> > >
> > > >
> > > >         public AMQMessageHandler(String connectionURI, String driverID,
> > > > Delegate exceptionDelegate, Form uiThread)
> > >
> > >         {
> > >
> > >             this.connecturi = connectionURI;
> > >
> > >             this.myQueue = "driver.channel." + driverID;
> > >
> > >             this.uiThread = uiThread;
> > >
> > >             this.exceptionDelegate    = exceptionDelegate;
> > >
> > >         }
> > >
> > >
> > > >         public void start()
> > >
> > >         {
> > >
> > >
> > > >             try
> > >
> > >             {
> > >
> > >                 this.factory = new ConnectionFactory(connecturi);
> > >
> > >                 this.connection = this.factory.CreateConnection();
> > >
> > >                 this.session = this.connection.CreateSession();
> > >
> > >                 this.destination = SessionUtil.GetDestination(session,
> > > > "queue://" + myQueue);
> > >
> > >                 this.messageConsumer =
> > session.CreateConsumer(destination);
> > >
> > >
> > >
> > >                 messageConsumer.Listener += new
> > > > MessageListener(messageConsumer_Listener);
> > >
> > >                 connection.ExceptionListener += new
> > > > ExceptionListener(connection_ExceptionListener);
> > >
> > >                 connection.Start();
> > >
> > >
> > > >             }
> > >
> > >             catch (Exception ex)
> > >
> > >             {
> > >
> > >                 uiThread.Invoke(exceptionDelegate,ex.Message);
> > >
> > >             }
> > >
> > >         }
> > >
> > >
> > > >         public delegate void RestartConnectionDelegate();
> > >
> > >
> > > >         private void restartConnection()
> > >
> > >         {
> > >
> > >             new System.Threading.Thread(threadedStartConnection).Start();
> > >
> > >         }
> > >
> > >
> > > >         private void threadedStartConnection()
> > >
> > >         {
> > >
> > >             int retryCount = 1;
> > >
> > >             bool keepTryingtoRestart = true;
> > >
> > >
> > > >             while (keepTryingtoRestart == true)
> > >
> > >             {
> > >
> > >                 //tsalem - add some kind of logging here
> > >
> > >                 //listBox.Items.Add("attempting to reconnect - pass " +
> > > > retryCount);
> > >
> > >                 System.Threading.Thread.Sleep(3000);
> > >
> > >
> > > >                 try
> > >
> > >                 {
> > >
> > >                     this.factory = new ConnectionFactory(connecturi);
> > >
> > >                     this.connection = this.factory.CreateConnection();
> > >
> > >                     this.session = this.connection.CreateSession();
> > >
> > >                     this.destination =
> > SessionUtil.GetDestination(session,
> > > > "queue://" + myQueue);
> > >
> > >                     this.messageConsumer =
> > > > session.CreateConsumer(destination);
> > >
> > >                     messageConsumer.Listener += new
> > > > MessageListener(messageConsumer_Listener);
> > >
> > >                     connection.ExceptionListener += new
> > > > ExceptionListener(connection_ExceptionListener);
> > >
> > >                     connection.Start();
> > >
> > >
> > > >                     keepTryingtoRestart = false;
> > >
> > >                 }
> > >
> > >                 catch (Exception ex)
> > >
> > >                 {
> > >
> > >                     uiThread.Invoke(exceptionDelegate, ex.Message +"\n" +
> > > > ex.StackTrace);
> > >
> > >                     //tsalem change this to check for keep retrying
> > rather
> > > > than on a counter
> > >
> > >                     if (retryCount == 50)
> > >
> > >                     {
> > >
> > >                         keepTryingtoRestart = false;
> > >
> > >                     }
> > >
> > >
> > > >                 }
> > >
> > >
> > >
> > >                 retryCount++;
> > >
> > >             }
> > >
> > >         }
> > >
> > >
> > > >
> > > >         public void messageConsumer_Listener(IMessage receivedMessage)
> > >
> > >         {
> > >
> > >             try
> > >
> > >             {
> > >
> > >                 ITextMessage message = receivedMessage as ITextMessage;
> > >
> > >                 message.Acknowledge();
> > >
> > >                 //tsalem - todo - handle message
> > >
> > >                 if (message.Text != null)
> > >
> > >                 {
> > >
> > >                     AMQUtil.Instance.ResponseAvailable(message.Text,
> > > > uiThread);
> > >
> > >                 }
> > >
> > >                 else
> > >
> > >                 {
> > >
> > >                     uiThread.Invoke(exceptionDelegate, "ERROR: AMQ
> > Message
> > > > is empty");
> > >
> > >                 }
> > >
> > >             }
> > >
> > >             catch (Exception ex)
> > >
> > >             {
> > >
> > >                 uiThread.Invoke(exceptionDelegate,ex.Message);
> > >
> > >             }
> > >
> > >         }
> > >
> > >
> > > >
> > > >
> > > >         void connection_ExceptionListener(Exception exception)
> > >
> > >         {
> > >
> > >             uiThread.Invoke(exceptionDelegate,exception.Message);
> > >
> > >
> > > >             if (exception is System.IO.IOException)
> > >
> > >             {
> > >
> > >                 //Invoke(new
> > > > RestartConnectionDelegate(threadedStartConnection));
> > >
> > >                 threadedStartConnection();
> > >
> > >             }
> > >
> > >         }
> > >
> > >     }
> > >
> > >
> > > regards,
> > > Tammer
> >
> > --
> > Tim Bish
> >
> > Open Source Integration: http://fusesource.com
> > ActiveMQ in Action: http://www.manning.com/snyder/
> >
> > Follow me on Twitter: http://twitter.com/tabish121
> > My Blog: http://timbish.blogspot.com/
> >
> >

-- 
Tim Bish

Open Source Integration: http://fusesource.com
ActiveMQ in Action: http://www.manning.com/snyder/

Follow me on Twitter: http://twitter.com/tabish121
My Blog: http://timbish.blogspot.com/


Mime
View raw message