Rhino Queues, Take 6

time to read 3 min | 521 words

As I stated before, I started writing a queuing system a few days ago, loosely based on my previous efforts in this area, but aimed to create a production ready queuing infrastructure that I can use in my own applications. The decision to build this was not made lightly, but I wanted a queuing system that met my needs, and was flexible enough to extend at needs.

The design goals stated for Rhino Queues were:

  • XCopy deployable
  • Zero configuration
  • Durable
  • Supports System.Transactions
  • Works well with Load Balancing hardware
  • Supports sub queues
  • Support arbitrarily large messages

It is now publically available, and I think it deserve some discussion.

Here is a very simple example of using it:

var queueManager = new QueueManager(new IPEndPoint(IPAddress.Loopback, 2200), "queues.esent");
var queue = queueManager.GetQueue("Web");

    using(var tx = new TransactionScope())
        var msg = queue.Receive();
        Console.WriteLine("Message from {0}:", msg.Headers["source"]);

This example is merely to show the API.

The actual software is pretty interesting. Communication between different queues are done using TCP, with a protocol that works well with load balancing hardware, making load balancing queued application as easy as balancing any HTTP based app.

You cannot see it in the API example, but the system is supporting System.Transactions fully, so sending a message is delayed until a transaction is committed, and receipt of a message would be rolled back on transaction rollback. We even support recovery after a hard crash, by plugging into the recovery mechanism that MSDTC offers us.

All messages are durable, so a system reboot will not remove them. While the default mode for Rhino Queues is an embedded component in your application (XCopy deployable), we still support the ability to deliver a message to a server that is down, by implementing a fairly flexible message retry mechanism.

Because Rhino Service Bus makes such a heavy use of this, we are also support sub queues, and we have no hard limit on the size of messages that we can deliver.

I delayed announcing this until I could finish integrating this completely into Rhino Service Bus, but this is now done, and should just work. Rhino Service Bus will still supports MSMQ, but I think that a lot of the work that we are going to do now on Rhino Service Bus would be with the new queuing infrastructure.