How does a VSI select an exact match in the incoming requests?
Does it compare only the arguments of the incoming request with the Request data arguments of the recorded transaction?
Or are attributes and metadata also considered to pick a match?
All supported DevTest releases.
By design it is only the arguments that are considered by a VSI to pick a match from the incoming requests.
If you wish the attributes/metadata also to be considered for the same, you have to use a DPH [XML DPH or Request data manager] to convert all the attributes/metadata in to arguments so that these get considered while VSI is looks for a match.
Elements can be automatically transferred as arguments using the XML DPH. By design, though, attributes will have to be specifically selected. If you want all attributes to be made into arguments automatically, then you will need to write some code of your own.