Question

I’m trying to use RMO to programmatically perform merge synchronization. I’ve basically copied the SQL Server example code, as follows:

// Create a connection to the Subscriber.
ServerConnection conn = new ServerConnection(subscriberName);

MergePullSubscription subscription;

try
{
    // Connect to the Subscriber.
    conn.Connect();

    // Define the pull subscription.
    subscription = new MergePullSubscription(subscriptionDbName, publisherName, publicationDbName,
                                             publicationName, conn, false);

    // If the pull subscription exists, then start the synchronization.
    if (subscription.LoadProperties())
    {
        // Check that we have enough metadata to start the agent.
        if (subscription.PublisherSecurity != null || subscription.DistributorSecurity != null)
        {
            subscription.SynchronizationAgent.Synchronize();
        }
        else
        {
            throw new ApplicationException("There is insufficent metadata to " +
                "synchronize the subscription. Recreate the subscription with " +
                "the agent job or supply the required agent properties at run time.");
        }
    }
    else
    {
        // Do something here if the pull subscription does not exist.
        throw new ApplicationException(String.Format(
            "A subscription to '{0}' does not exist on {1}",
            publicationName, subscriberName));
    }
}
catch (Exception ex)
{
    // Implement appropriate error handling here.
    throw new ApplicationException("The subscription could not be " +
        "synchronized. Verify that the subscription has " +
        "been defined correctly.", ex);
}
finally
{
    conn.Disconnect();
}

I’ve got the server merge publication defined correctly, but when I run the above code, I get a null reference exception on the call to:

subscription.SynchronizationAgent.Synchronize();

The stack trace is as follows:

at Microsoft.SqlServer.Replication.MergeSynchronizationAgent.StatusEventSinkMethod(String message, Int32 percent, Int32* returnValue)

at Test.ConsoleTest.Program.SynchronizePullSubscription() in F:\Visual Studio Projects\Test\source\Test.ConsoleTest\Program.cs:line 124

It seems, from the stack trace, like something to do with the Status event, but I don’t have a handler defined, and defining one makes no difference.

Answer 1

I didn’t really get to the bottom of why this was happening. I could get it to work on one machine, but on another machine I constantly got the NullReferenceException.

It turns out that I was referencing the assemblies in the SQL Server 2005 SDK folder. I removed these and referenced the ones from SQL Server 2008 instead and it’s worked fine since.

Maybe this will help somebody else.