WCF Durable Services
The advent of .Net 3.5 has made two of its core tenets: WCF and WF interact with each other and interdependent to a certain extent. One notable product of this association is WCF Durable Services. What is it? A Durable Service (new in WCF 3.5) is an implementation of a long running WF service, which persists the state of the service and its message contents on a per client basis. The state can be persisted "out-of-process" and the client can resume the execution at the last saved point. The persisting and depersisting activities (also called dehydrating and rehydrating) are done immediately prior to and after a service method is called. The persistence store is fully configurable (via config file) and could be SQL Server, file system or any custom store. A Durable Service inherently supports durability and reliability. Why is it required? The most apt use of a Durable Service would be in business scenarios with heavy data dependent tasks that require per-client persistence a