I'd like to use WCF+MSMQ(netMsmqBinding) and I was wondering if I'd need to install anything MSMQ related at the client side, other than my client application and the .NET framework of-course.
Yes you need MSMQ installed on both the service and the consumer sides.
Edit: just to embellish the answer - the reason you need MSMQ installed is that when you send a message to a queue on another machine, what is really happening is that you are sending a message to the queue manager on the senders machine, which is sending a message to the queue manager on the receivers machine, which is sending a message to the queue.
Each "send" is a single logical action and is what gives MSMQ durability.
Related
I went thought NServiceBus documentation including the durable messaging one. What I understand is that when the server is offline the messages continue to go into the server's input queue which get picked up when server comes back online.
But what if the server is completely down and the input queue is not accessible?
I'm using Bus.Send from the client.
It depends on what transport you're using.
In the case of a brokered message queue, like Azure Service Bus, as long as that service is available, the fact the machine that will eventually retrieve the messages is offline is irrelevant, as that machine is simply asking the external queuing service for messages. The same goes for a transport like SQL Server.
In the case of a transport like MSMQ, which is a store a forward style queue, the messages will remain in a local outgoing queue until the remote machine becomes available.
Can you double check that you are looking in the correct spot? If you aren't getting an error out of NServiceBus when you Send, then MSMQ is installed. If it can't be reached or the service is stopped you should get errors.
The Outbound queues are in a different place as illustrated here:
http://blogs.msdn.com/cfs-filesystemfile.ashx/__key/communityserver-components-postattachments/00-09-06-31-16/outgoingempty.JPG
As RMD indicated, this is an advantage of the store and forward MSMQ transport.. the local outbound queue should just stack these up until the remote server is available.
Thx.
Joe
I know that once a message has been delivered to the MSMQ by a WCF client, the netmsmqbinding provides retries out of the box in case the service faults.
But if my client fails to put the message in the MSMQ in the first place, is there an out of the box client retry available in WCF or do I have to implement a client queue and retry logic in my client code?
Thanks
It's a highly unlikely scenario that your messages sent to the service will not even be placed in the client queue in the first place, if you have MSMQ server running on the client station and the MSMQ listener service is up and running you should have nothing to worry about. I don't think MSMQ offers anything to check this for you, you should code some method on your client to periodically Peek() the local queue and send an acknowledgment receipt for every message that has reached the queue, this is feasible since you can easily access your local queues in code and also every message sent via MSMQ from a client to a service will always go trhough the local queue. You can also tell that the message reaches the queue if your Send() method desn't return an error. But I don't think you really need to worry about message son the client not reaching the local queue first.
I have a MSMQ queue and I need to implement a listener that is executed periodically or at specified time (i.e. nightly) to process messages in the queue.
WCF provides netMsmqBinding that allows sending messages to other service via MSMQ. I wonder is it possible to implement the WCF service to consume messages at specified time or periodically in equal intervals? Or WCF always consumes message as soon as it arrives?
For example I need to check queue every hour, and if there are any messages - process them.
One more question is about concurrency. Can I configure WCF service to use limited number of threads (e.g. 2) for queue message handling?
Thanks
Your best bet is to host the MSMQ consumer in a windows service and then configure a windows scheduled task to start it up and shut it down (eg with a powershell script) as per your service window requirements.
EDIT: I believe NServiceBus sagas can also support this requirement but it does not use WCF.
We are using MSMQ right now with WCF activation feature, it enables us not to pull queue to read messages. It like push message to application.
As we are looking at porting from MSMQ to RabbitMQ going through what we need from message queue.
I can't anything regarding RabbitMQ .net client support for receiving message notification from subscribed queue?
Is there anything in RabbitMQ with .net which can do push notification to subscriber like MSMQ?
Or we need service running which constantly checks for message?
In AMQP (and RabbitMQ), there are two ways to retrieve messages: basic.get and basic.consume.
Basic.get is used to poll the server for a message. If one exists, it is returned to the client. If not, a get-empty is returned (the .NET method returns null).
Basic.consume sets the consumer for the queue. The broker pushes messages to the consumer as they arrive. You can either derive DefaultBasicConsumer, which gives you your own custom consumer, or you can use the Subscription Message Pattern, which gives you a blocking nextDelivery().
For more information, check out the API guide linked above and the .NET Client Userguide. Also, a great place to ask RabbitMQ-related questions is the rabbitmq-discuss mailing list.
I think you are after something like the EventingBasicConsumer. See also this question/answer
That is a feature provided by WAS (Windows Activation Service). Right now WAS has listener adapters for net.pipe, net.msmq and net.tcp (and its port sharing service). I guess you would need a specific AMQP listener adapter.
This may help http://msdn.microsoft.com/en-us/library/ms789006.aspx
I have a scenario where I need a desktop console app to communicate with a Windows Azure Queue... the most important thing is that the message is received by the server eventually. Also, the desktop app may be disconnected from the Internet sometimes. In the traditional WCF+MSMQ approach you'd be able to send a message which would be cached in MSMQ until MSMQ could reach the Server's MSMQ and send the message. What's the equivalent when Windows Azure is the server-side?
Is it possible for the same approach to be used, where MSMQ just communicates with a Windows Azure Queue rather than an MSMQ on a Windows Server?
Maybe Windows Azure Queue is the wrong approach? I have heard about something called message buffer, but don't know what this is (yet!).
thanks for your help
Kris
You could write an MSMQ listener service that finishes moving the message to the Azure queue when the connection to the internet has been reestablished. I don't think this would be too difficult.
Update
Perhaps my answer wasnt clear. Based on the question the client is occasionally connected to the internet so you need a way to park the message until the intertubes get untangled. Using Windows the easiest way to do this is to put the message in an MSMQ local queue. YOu then have a service monitoring that queue. If there is a message and it can get to the service hosted in the cloud it sends the message. Once the message has been sent it can be deleted from the queue.
In order to queue a message to Azure Queue Storage you have to be connected to the Internet. If you want to handle disconnected scenarios, that is totally up to you. I would keep the solution very simple and use a local storage such as SQL Server Compact and then send the messages as soon as there's connectivity, maybe with the aid of a Windows Service (so that you don't need to run the desktop app).
You can do this with the Azure AppFabric Service Bus Message Buffers - there is no need to use a Queue. Check out the related sample downloads on the following site: http://www.idesign.net/idesign/DesktopDefault.aspx?tabindex=5&tabid=11 - they should answer your questions much better than I can.
Regards