Optimizing workflow engines

1. A computer program product comprising a tangible computer readable recordable storage memory including computer useable program code for implementing a workflow, the computer program product including:

computer useable program code for merging a workflow to create a virtual graph, wherein the workflow comprises two or more directed acyclic graphs (DAGs), wherein said merging comprises:

applying a label to each node of the two or more directed acyclic graphs, wherein nodes representing a same computation in each directed acyclic graph have a same label applied thereto;

assigning each node in the two or more directed acyclic graphs with a unique label to a unique node in the virtual graph; and

assigning each node in the two or more directed acyclic graphs that shares the same label with one or more additional nodes are assigned to a same node in the virtual graph;

computer useable program code for mapping each of one or more nodes of the virtual graph to one or more physical nodes; and

computer useable program code for using a message passing scheme to implement a computation via the one or more physical nodes.

2. The computer program product of claim 1 , wherein the computer useable program code for using a message passing scheme to implement a computation via the one or more physical nodes comprises:

computer useable program code for parsing a message to determine a DAG identification (ID) of the message;

computer useable program code for putting the message in a corresponding buffer;

computer useable program code for beginning a process of executing a job if a size of the buffer is equal to a number of messages the buffer has to have before beginning its execution.

3. The computer program product of claim 1 , wherein merging a workflow to create a virtual graph comprises merging two or more DAGs even if the two or more DAGs do not have a same predecessor.

4. The computer program product of claim 1 , wherein merging a workflow to create a virtual graph comprises merging two or more DAGs even if the two or more DAGs do not have a same successor.

5. The computer program product of claim 1 , wherein merging a workflow to create a virtual graph comprises maximizing a number of nodes in the two or more DAGs having a same numerical label.

6. The computer program product of claim 1 , further comprising computer useable program code for using a message passing scheme to queue one or more computations in a node depending on resources and licenses available in the node.

7. The computer program product of claim 1 , further comprising computer useable program code for using a directory-based system in a virtual node directory to keep track of one or more merging operations that have been performed.

8. The computer program product of claim 1 , further comprising computer useable program code for using a message ID to track one or more messages in one or more merged DAGs.

9. A system for implementing a workflow, comprising:

a memory; and

at least one processor coupled to the memory and operative to:

merge a workflow to create a virtual graph, wherein the workflow comprises two or more directed acyclic graphs (DAGs), wherein said merging comprises:

applying a label to each node of the two or more directed acyclic graphs, wherein nodes representing a same computation in each directed acyclic graph have a same label applied thereto;

assigning each node in the two or more directed acyclic graphs with a unique label to a unique node in the virtual graph; and

assigning each node in the two or more directed acyclic graphs that shares the same label with one or more additional nodes are assigned to a same node in the virtual graph;

map each of one or more nodes of the virtual graph to one or more physical nodes; and

use a message passing scheme to implement a computation via the one or more physical nodes.

10. The system of claim 9 , wherein the at least one processor coupled to the memory operative to use a message passing scheme to implement a computation via the one or more physical nodes is further operative to:

parse a message to determine a DAG identification (ID) of the message;

put the message in a corresponding buffer;

begin a process of executing a job if a size of the buffer is equal to a number of messages the buffer has to have before beginning its execution.

11. The system of claim 9 , wherein merging a workflow to create a virtual graph comprises merging two or more DAGs even if the two or more DAGs do not have a same predecessor.

12. The system of claim 9 , wherein merging a workflow to create a virtual graph comprises merging two or more DAGs even if the two or more DAGs do not have a same successor.

13. The system of claim 9 , wherein merging a workflow to create a virtual graph comprises maximizing a number of nodes in the two or more DAGs having a same numerical label.

14. The system of claim 9 , wherein the at least one processor coupled to the memory is further operative to use a message passing scheme to queue one or more computations in a node depending on resources and licenses available in the node.

15. The system of claim 9 , wherein the at least one processor coupled to the memory is further operative to use a directory-based system in a virtual node directory to keep track of one or more merging operations that have been performed.

16. The system of claim 9 , wherein the at least one processor coupled to the memory is further operative to use a message ID to track one or more messages in one or more merged DAGs.