We've got some web services that utilise EnsLib.SOAP.Service/EnsLib.REST.Service. These do some further requests to a few operations to call some other services and return the combined results.
An issue that we are noticing is that some of the usage involves users hitting the refresh button a few too many times and generating a lot of requests. This is mostly an issue when the service that the operations are calling are down or slow to respond. IRIS starts using a lot of RAM when this occurs and has caused outages by getting through an extra 50-60GB of RAM.