Processing model-based commands for distributed applications

One or more storage medium having stored computer-executable instructions which, when executed by one or more processors of a computer system, implement a method for distributing the implementation of a command, the method comprising:

• an act of a first executive service receiving a command request for a distributed application, the command request including a command reference to a command definition model defining a corresponding command, the command request also including a reference to model, the command request indicating that the corresponding command is to be implemented for the application model;
• an act of the first executive service determining that it is already running a plurality of other model-based commands;
• an act of the first executive service querying the repository to determine if other executive services are available;
• an act of the first executive service receiving an indication that a second executive service is available for processing model-based commands;
• and
• an act of the first executive service passing the command request to the second executive service in response to the indication that the second executive service is available so as to balance the load of command processing across the plurality of executive services.

One or more storage medium having stored computer-executable instructions which, when executed by one or more processors of a computer system, implement a method for processing a model-based command for a distributed application, the method comprising:

• an act of receiving a command request for a distributed application, wherein the command request includes a command reference to a command definition model that defines a corresponding command and that identifies a workflow model, wherein the command request also includes a reference to an application model for the distributed application that is a declarative model that describes the structure and behavior of the distributed application by defining general operations of one or more modules in the distributed application, and wherein the command request indicates that the corresponding command is to be implemented for the application model;
• an act of creating a command record for the received command request in the repository, wherein the command record stores information related to implementing the command request;
• an act of identifying the workflow model from the command definition model, wherein the workflow model describes how to implement the received command request for the application model by defining a set of pre-defined activities configured to interoperate to implement the command request for the application model;
• an act of accessing the workflow model from the repository;
• an act of creating an instance of the workflow from the workflow model, wherein the workflow instance has a command ID and includes the set of pre-defined activities configured to interoperate to implement the command request for the application model;
• an act of storing the command ID in the command record;
• an act of submitting the application model reference to the workflow instance to initiate the workflow instance for the distributed application;
• and
• an act of recording information related to the behavior of the workflow instance within the command record as the workflow instance implements the command request for the application model and for the distributed application.

One or more storage medium having stored computer-executable instructions which, when executed by one or more processors of a computer system, implement a method for releasing a command definition model for further use, the method comprising:

• an act of receiving a command request for a distributed application, wherein the command request includes a command reference to a command definition model that defines a corresponding command and that identifies a corresponding workflow model, wherein the command request also includes a reference to an application model for the distributed application that is a declarative model that describes the structure and behavior of the distributed application by defining general operations of one or more modules in the distributed application, and wherein the command request indicates that the corresponding command is to be implemented for the application model and for the distributed application;
• an act of creating a command record for the received command request in the repository, wherein the command record stores information related to implementing the command request;
• an act of creating an instance of the workflow from the corresponding workflow model, wherein the workflow model describes how to implement the received command request for the application model, and wherein the workflow instance includes a set of pre-defined activities configured to interoperate to implement the command request for the application model;
• an act of locking the application model to prevent further access to the application model while the workflow instance implements the command request for the application model;
• an act of submitting the application model reference to the workflow instance to initiate the workflow instance for the application model;
• an act of recording information related to the behavior of the workflow instance within the command record as the workflow instance implements the command request for the application model for the application model;
• an act of determining that the workflow instance is to be stopped;
• an act of determining that the workflow instance is stopped;
• and
• an act of releasing the lock on the application model such that other commands can be implemented for the application model.