One of my colleagues recently lost a bit of work because of a tricky “gotcha” with messages going through an ordered delivery channel in BizTalk Server.
For someone viewing suspended messages in the BizTalk Administration Console, there is no obvious way to identify a suspended port as an ordered delivery port. In the screenshot below, I’ve stopped an ordered delivery send port, and sent five messages through.
As you can see, the console only shows a “1 Count” of suspended ports. That’s clearly not the case. How do I see the REAL count of messages? I’ve got two choices. First, I can double-click the suspended port and switch to the “Messages” tab.
Another way to see the messages is to right-click the suspended instance and select “Show Messages.”
So what’s the gotcha? My buddy wanted to delete a few of the messages in the queue, so he right-clicked the messages he wanted to delete, and chose “Terminate Instance.”
To his absolute horror, this action terminated all the messages in the suspended port instance, instead of his expected goal of eliminating only choice messages. Yowza. If you turn on the “Stop sending subsequent messages on current message failure” flag on the port, you CAN eliminate a message, BUT, it’s only the front-most message in the queue that blocking up the pipe. To see this, I flipped that flag on, and sent a number of messages in. Now if I right-click the single suspended instance, I have the option to “Find Failed Message.”
The message that is shown afterwards can be selected and deleted in this scenario. So, I was hoping that if I manipulate the query in the Admin Console, I too could delete ANY message in the queue. Alas, even searching by “Message ID” and returning a single instance from the queue (as the “Failed Message” processing does), doesn’t afford me the chance to delete any message of my choosing. All I can still do is “Terminate Instance” instead.
So the takeaway is …
- Warn administrators to be careful when deleting suspended instances associated with ordered delivery ports. They may THINK they are deleting a single instance, but in fact, are deleting dozens or hundreds of underlying messages.
- You cannot terminate individual messages that are queued up for ordered delivery.
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Richard Seroter's Architecture Musings 
Hi, what adapter are you using? I find that even though we have the “Stop sending subsequent messages on current message failure” flag consistently turned on on all the send ports, the option to “find failed message” arbitrarily does or does not appear. We are using MLLP.