Ensuring that a given transactional unit of work arrives at an appropriate server instance. A server instance receives a request that is associated with a unit of work. The server instance that received the request determines whether it is responsible for the unit of work associated with that request. When the server instance is responsible for the unit of work, the server instance processes the request. When the server instance is not responsible for the unit of work, it attempts to register its interest in the unit of work. If this attempt is successful, then the server instance can process the request. If the attempt is unsuccessful, then the responsible server instance is located and the request is forwarded to the responsible server instance.