Abstract: A workflow hosting system is described herein that allows non-messaging workflows to be hosted by a message-based service host. The system provides a host implementation, which can be used to host non-messaging workflows, or workflows that either do not begin with a message activity or do not use messaging activities at all. When the host receives a message for a workflow service, if it is not already running (or persisted), the system creates a new workflow service instance. If a workflow does not begin with a message activity, it cannot be started by sending a message because there is no activity to receive the message. To host a non-messaging workflow, the system provides a translation layer that sits between the communication layer and the workflow with methods that a developer can override to correctly activate the workflow.

Abstract: A workflow hosting system is described herein that allows non-messaging workflows to be hosted by a message-based service host. The system provides a host implementation, which can be used to host non-messaging workflows, or workflows that either do not begin with a message activity or do not use messaging activities at all. When the host receives a message for a workflow service, if it is not already running (or persisted), the system creates a new workflow service instance. If a workflow does not begin with a message activity, it cannot be started by sending a message because there is no activity to receive the message. To host a non-messaging workflow, the system provides a translation layer that sits between the communication layer and the workflow with methods that a developer can override to correctly activate the workflow.

Abstract: A client programming model with abstraction hides from an underlying client application or application program interface (API) the details of where each element of data is located, and which copy of the data is resident on an available server and associated databases. The model wraps a database, such as a virtual database, and provides data-dependent and application-dependent routing, failover, and operational administration.