What am I missing? MSMQ Perf Issue
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I am getting some strange perf numbers from MSMQ, and I can’t quite figure out what is going on here.

The scenario is simple, I have a process reading from queue 1 and writing to queue 2. But performance isn’t anywhere near where I think it should be.

In my test scenario, I have queue 1 filled with 10,000 messages, each about 1.5 Kb in size. My test code does a no op move between the queues. Both queues are transactional.

Here is the code:

private static void CopyData()
{
    var q1 = new MessageQueue(@".\private$\test_queue1");
    var q2 = new MessageQueue(@".\private$\test_queue2");
    q2.Purge();
    var sp = Stopwatch.StartNew();
    while (true)
    {
        using (var msmqTx = new MessageQueueTransaction())
        {
            msmqTx.Begin();

            Message message;
            try
            {
                message = q1.Receive(TimeSpan.FromMilliseconds(0), msmqTx);
            }
            catch (MessageQueueException e)
            {
                Console.WriteLine(e);
                break;
            }

            q2.Send(message, msmqTx);

            msmqTx.Commit();
        }
    }
    Console.WriteLine("{0:#,#}", sp.ElapsedMilliseconds);
}

Using this code, it takes 236.8 seconds to move 10,000 messages. If I use System.Transactions, instead of MSMQ’s internal transactions, I get comparable speeds.

Just to give you an idea, this is about 40 messages a second, this number is ridiculously low.

Changing the code so each operation is a separate transaction, like this:

private static void CopyData()
{
    var q1 = new MessageQueue(@".\private$\test_queue1");
    var q2 = new MessageQueue(@".\private$\test_queue2");
    q2.Purge();
    var sp = Stopwatch.StartNew();
    while (true)
    {

        Message message;
        try
        {
            message = q1.Receive(TimeSpan.FromMilliseconds(0), MessageQueueTransactionType.Single);
        }
        catch (MessageQueueException e)
        {
            Console.WriteLine(e);
            break;
        }

        q2.Send(message, MessageQueueTransactionType.Single);
    }
    Console.WriteLine("{0:#,#}", sp.ElapsedMilliseconds);
}

Means that it takes 16.3 seconds, or about 600 messages per second, which is far closer to what I would expect.

This is on a quad core machine 8 GB RAM (4 GB free), so I don’t think that it is the machine that is causing the problem. I can see similar results on other machines as well.

Am I missing something? Is there something in my code that is wrong?

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