BizTalk 2013 R2 - Rate based Throttling on flooding messages

Question

We have a solution that takes a message, and sends it to a web API. Every day, an automatic procedure is run by another department that passes thousands of records into the messagebox, which seems to cause errors related to the API solicit-response port (strangely these errors don't allude to a timeout, but they do only trigger when such a massive quantity of data is sent downstream).

I've contacted the service supplier to determine the capacity of their API calls, so I'll be able to tailor our flow once I have a better idea.

I've been reading up on Rate Based Throttling this morning, and have a few questions I can't find an answer to;

• If throttling is enabled, does it only process the Minimum number of samples/messages? If so, what happens to the remaining messages? I read somewhere they're queued in memory, but only of a max of 100, so where do all the others go?

• If I have 2350 messages flood through in the space of 2 seconds, and I want to control the flow, would changing my Sampling Window duration down to 1 second and setting Throttling override to initiate throttling make a difference?

Answer 1

If you are talking about Host Throttling setting, the remaining messages will be in the message box database and will show as being in a Dehydrated state.

You would have to test the throttling settings under load. If you get it wrong it can be very bad. I've come across one server where the settings were configured incorrectly and it is constantly throttling.