Is there any limitation to the number of parrallel activities that can be run in WF4 hosted in IIS

Question

I am trying to figure out the best way of achieving the following.

I have a web service that will be called by a page within a web application. The service itself needs to return a result within a second or two at the most to keep the page usable.

The service will need to call at least a dozen separate services to accumulate the data required before aggregating it for delivery to the page.

I am considering using WF4 with a Parallel activity to manage the multiple service calls.

My question is, will this work in practice, or will the calls be queued in some way because there are so many running at the same time?

I really don't want to turn this into a batch process if I can help it.

Thanks.

Answer 1

If you are using the Send and the ReceiveReply activities the calls will be done in parallel. There is no limitation with workflow on the number of parallel branches. If you start using custom activities to call other services you need to make sure they are asynchronous otherwise all calls will become sequential.