The use of a single physical server in which there are multiple virtual nodes operating different components of a distributed application under test. Each virtual node emulates an actual physical node in a prospective distributed environment. The virtual nodes might be, for example, virtual machines or emulated services, and may operate their own operating system within the context of the virtual node. The distributed environment is emulated on the physical server by having the virtual nodes communicate with each other using the protocols that they would normally use in a deployed distributed environment. A configuration data source may be used to setup and perhaps upgrade the virtual nodes so as to emulate the distributed environment. Accordingly, the distributed application may be tested without actually setting up a distributed environment.