Fault-tolerant system and methods with trusted message acknowledgement

A method to be performed by a computer network comprising a plurality of clients and a plurality of workflow engines:

• providing distributed queuing of workflows, whose execution can be requested by one or more execution-requesting clients, among the plurality of workflow engines;
• and
• determining whether a workflow has been successfully completed by a first workflow engine on behalf of an execution-requesting client;
• only if so, sending a notification to the execution-requesting client;
• otherwise, assigning the workflow to a subsequent workflow engine by sending it a work assignment message, and the subsequent workflow engine alone performing the workflow;
• and
• sending a notification to the execution-requesting client only if the workflow is successfully completed by the subsequent workflow engine;
• wherein sending is performed by a certified messaging capability;
• wherein the certified messaging capability is performed by a load manager;
• and
• wherein the load manager comprises a commercially available middleware product;
• the certified messaging capability sending the notification to the execution-requesting client only if the workflow is successfully completed by the subsequent workflow engine.

A computer adapted for use in a computer network comprising a plurality of workflow engines, the computer executing a computer program, the computer program operating the computer in a fault-tolerant manner and comprising the operations of:

• requesting a workflow execution on behalf of a client;
• a distributed queuing capability assigning the workflow execution to a first workflow engine;
• determining whether the workflow execution has been successfully completed by the first workflow engine;
• only if so, sending a notification to the client;
• otherwise, assigning the workflow execution to a subsequent workflow engine by sending it a work assignment message, and the subsequent workflow engine alone performing the workflow;
• and
• sending a notification to the client only if the workflow is successfully completed by the subsequent workflow engine;
• wherein sending is performed by a certified messaging capability;
• and
• wherein the certified messaging capability is performed by a certified message receiver in the first workflow engine;
• the certified messaging capability sending the notification to the client only if the workflow execution is successfully completed by the subsequent workflow engine.

A computer network comprising:

• a plurality of clients;
• a plurality of workflow engines;
• and
• at least one computer program, the computer program operating in a fault-tolerant manner and performing the operations of:
• requesting a workflow execution on behalf of a client;
• assigning the workflow execution to a first workflow engine;
• determining whether the workflow execution has been successfully completed by the first workflow engine;
• only if so, sending a notification to the client;
• otherwise, assigning the workflow execution to a subsequent workflow engine by sending it a work assignment message, and the subsequent workflow engine alone performing the workflow;
• and
• sending a notification to the client only if the workflow is successfully completed by the subsequent workflow engine;
• wherein sending is performed by a certified messaging capability;
• and
• wherein the certified messaging capability is performed by a certified message receiver in the first workflow engine;
• the certified messaging capability sending the notification to the client only if the workflow execution is successfully completed by the subsequent workflow engine.

A computer-readable medium containing computer instructions for instructing a processor, the processor adapted for use in a computer network comprising a plurality of workflow engines, wherein the instructions comprise:

• requesting a workflow execution on behalf of a client;
• a distributed queuing capability assigning the workflow execution to a first workflow engine;
• determining whether the workflow execution has been successfully completed by the first workflow engine;
• only if so, sending a notification to the client;
• otherwise, assigning the workflow execution to a subsequent workflow engine by sending it a work assignment message, and the subsequent workflow engine alone completing the workflow;
• and
• sending a notification to the client only if the workflow is successfully completed by the subsequent workflow engine;
• wherein sending is performed by a certified messaging capability;
• and
• wherein the certified messaging capability is performed by a certified message receiver in the first workflow engine;
• the certified messaging capability sending the notification to the client only if the workflow execution is successfully completed by the subsequent workflow engine.

An article comprising a machine-accessible medium having instructions for instructing a processor forming part of a plurality of workflow engines, wherein the instructions, when accessed, result in a machine performing:

• requesting a workflow execution on behalf of a client;
• assigning the workflow execution to a first workflow engine;
• determining whether the workflow execution has been successfully completed by the first workflow engine;
• only if so, sending a notification to the client;
• otherwise, assigning the workflow execution to a subsequent workflow engine by sending it a work assignment message, and the subsequent workflow engine alone completing the workflow;
• and
• sending a notification to the client only if the workflow is successfully completed by the subsequent workflow engine;
• wherein sending is performed by a certified messaging capability;
• and
• wherein the certified messaging capability is performed by a certified message receiver in the first workflow engine;
• the certified messaging capability sending the notification to the client only if the workflow execution is successfully completed by the subsequent workflow engine.