Question

I have reduced a problem I’m having to the following example code:

var inQueue = ".\private$\testqueue";
using (var ts = new TransactionScope())
{
    using (var q = new MessageQueue(inQueue, QueueAccessMode.Send))
    {
        for (var i = 0; i < 100000; ++i)
        {
            var msg = new Message(i);
            q.Send(msg, MessageQueueTransactionType.Automatic);
        }
    }
    ts.Complete();
}

As you can see, all it does it write 100,000 integers to a (transactional, local) queue using the TransactionScope pattern. My understanding is that this type of operation would not escalate to a DTC transaction.

However, if I open up Component Services while this is running, I can see the transaction in the Local DTC > Transaction List. This means that the transaction has been escalated, right?

Why would this be happening? I was prompted to this by bad performance in another program, and it would appear that the use of DTC for such a simple transaction may be a factor. Regardless, I just want to understand the cause.

Any help would be appreciated.

Answer 1

From http://geekswithblogs.net/dotnetrodent/archive/2008/04/16/121279.aspx

If you only need to do transactional work related to message queues,
without any other resources that need to be in the transactional
context (like databases), don’t use the TransactionScope, but rather
the MessageQueueTransaction class. Using this
class to control transactions related only to message queues comes
with a lesser performance penalty than using a full distributed
transaction controlled by DTC.