TRANSPARENTLY STATEFUL EXECUTION OF STATELESS APPLICATIONS

• US 20110040826A1
• Filed: 08/13/2009
• Published: 02/17/2011
• Est. Priority Date: 08/13/2009
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Ittel, Jens C., Chadzelek, Thomas
• Granted Patent: US 9,749,387 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/142 Managing session states for stateless protocols; Signalling session states; State transitions; Keeping-state mechanisms

Abstract

This disclosure provides various embodiments for providing transparently stateful execution of stateless applications. A request associated with an application is received and includes at least one operation to be executed by the application as well as a set of first state information. The application determines if the operations are to be executed statelessly or not. If the application is to be executed statelessly, the first state information is retrieved from the request and used to initialize the application. If not, then the first state of the application is retrieved from a location other than the received request. The operations are then executed by the application in the application'"'"'s appropriate first state. A response including the relevant information associated with the response as well as an updated set of state information identifying the application'"'"'s second state is generated and transmitted to the client.

Claims

1. A computer program product for providing stateful execution of a stateless application, the computer program product comprising computer readable instructions embodied on tangible media and operable when executed to:

receive a request associated with an application, the request received from a client associated with the application and identifying at least one operation to be performed by the application, the request storing a set of state information identifying a first state for the application to be initialized prior to executing the operations;

determine if a first of the one or more operations of the request is to be executed in one of a stateless mode or a stateful mode;

execute the operations identified in the received request; and

generate a response to the client associated with the received request, the response comprising the results of the operations and a set of updated state information identifying a second state of the application as determined after the execution of the at least one operation.

2. The computer program product of claim 1, further operable when executed to:

if the first operation is to be executed in a stateless mode;

retrieve the set of state information from the request; and

initialize the application to the state identified by the retrieved set of state information;

or

if the first operation is to be executed in a stateful mode, set the application to a state identified by a locally-maintained set of stored state information separate from the set of state information included with the received request.

3. The computer program product of claim 1, wherein the request comprises a uniform resource locator (URL) associated with the application, the instructions identifying at least one operation to be performed by the application comprising a web-addressable portion of the URL associated with a particular portion of the application and the set of state information identifying the first state comprising one or more parameters associated with the URL.

4. The computer program product of claim 3, wherein the one or more parameters associated with the URL are embedded within the URL as parameters.

5. The computer program product of claim 3, wherein the one or more parameters comprise a portion of the hypertext transfer protocol (HTTP) request sent with the URL.

6. The computer program product of claim 1, wherein determining if the operations of the request are to be executed in one of a stateless mode or a stateful mode comprises dynamically determining a preferred mode of execution.

7. The computer program product of claim 6, wherein the dynamic determination of the preferred mode of execution is at least partially based on the runtime environment of the application.

8. The computer program product of claim 7, wherein the dynamic determination of the preferred mode of execution comprises a determination of at least one of the following:

the available main memory associated with storage of state information at the server;

the number of clients sending requests to the application within a specified period;

whether each component of the application is enabled to execute statelessly;

or

the available processing resources available to the application upon receiving the request.

9. The computer program product of claim 1, wherein the response comprises a URL associated with the application, the set of updated state information identifying the second state of the application comprising one or more parameters associated with the URL.

10. The computer program product of claim 2, wherein the request comprises a first request, the response comprises a first response, the client comprises a first client, the instructions comprise a first set of instructions, and the response comprises a first response, further operable when executed to:

receive a second request associated with the application, the second request received from a second client associated with the application and identifying at least one operation to be performed by the application, the second request storing a set of state information identifying the second state for the application to be initialized prior to executing the operations;

determine if a first of the one or more operations of the second request is to be executed in one of a stateless mode or a stateful mode;

if the first operation of the second request is to be executed in a stateless mode;

retrieve the set of state information from the second request; and

initialize the application to the second state identified by the retrieved set of state information;

or

if the first operation of the second request is to be executed in a stateful mode, set the application to a state identified by the locally-maintained set of stored state information separate from the set of state information included with the received second request;

execute the operations identified in the received second request; and

generate a second response to the client associated with the received second request, the second response comprising the results of the operations and a set of updated state information identifying a third state of the application as determined after the execution of the second instructions.

11. The computer program product of claim 10, wherein the operations of the first request are executed by the application in a stateless mode and the operations of the second request are executed by the application in a stateful mode.

12. The computer program product of claim 11, wherein the first client and the second client are identical.

13. A computer-implemented method for providing stateful execution of a stateless application, the method steps performed by a processor and comprising:

receiving a request associated with an application, the request received from a client associated with the application and identifying at least one operation to be performed by the application, the request storing a set of state information identifying a first state for the application to be initialized prior to executing the operations;

determining if a first of the one or more operations of the request are to be executed in one of a stateless mode or a stateful mode;

executing the operations identified in the received request; and

generating a response to the client associated with the received request, the response comprising the results of the operations and a set of updated state information identifying a second state of the application as determined after the execution of the at least one operation.

14. The computer-implemented method of claim 13 further comprising:

if the first operation is to be executed in a stateless mode;

retrieving the set of state information from the request; and

initializing the application to the state identified by the retrieved set of state information;

or

if the first operation is to be executed in a stateful mode, setting the application to a state identified by a locally-maintained set of stored state information separate from the set of state information included with the received request.

15. The computer-implemented method of claim 13, wherein the request comprises a uniform resource locator (URL) associated with the application, the instructions identifying at least one operation to be performed by the application comprising a web-addressable portion of the URL associated with a particular portion of the application and the set of state information identifying the first state comprising one or more parameters associated with the URL.

16. The computer-implemented method of claim 15, wherein the one or more parameters associated with the URL are embedded within the URL as parameters.

17. The computer-implemented method of claim 15, wherein the one or more parameters comprise a portion of the hypertext transfer protocol (HTTP) request sent with the URL.

18. The computer-implemented method of claim 13, wherein determining if the operations of the request are to be executed in one of a stateless mode or a stateful mode comprises dynamically determining a preferred mode of execution.

19. The computer-implemented method of claim 18, wherein the dynamic determination of the preferred mode of execution is at least partially based on the runtime environment of the application.

20. The computer-implemented method of claim 19, wherein the dynamic determination of the preferred mode of execution comprises a determination of at least one of the following:

the available main memory associated with storage of state information at the server;

the number of clients sending requests to the application within a specified period;

whether each component of the application is enabled to execute statelessly;

or

the available processing resources available to the application upon receiving the request.

21. The computer-implemented method of claim 13 wherein the response comprises a URL associated with the application, the set of updated state information identifying the second state of the application comprising one or more parameters associated with the URL.

22. The computer-implemented method of claim 14, wherein the request comprises a first request, the response comprises a first response, the client comprises a first client, the instructions comprise a first set of instructions, and the response comprises a first response, further comprising:

receiving a second request associated with the application, the second request received from a second client associated with the application and identifying at least one operation to be performed by the application, the request storing a set of state information identifying the second state for the application to be initialized prior to executing the operations;

determining if a first of the one or more operations of the second request is to be executed in one of a stateless mode or a stateful mode;

if the first operation of the second request is to be executed in a stateless mode;

retrieving the set of state information from the second request; and

initializing the application to the second state identified by the retrieved set of state information;

or

if the first operation of the second request are to be executed in a stateful mode, setting the application to a state identified by the locally-maintained set of stored state information separate from the set of state information included with the received second request;

executing the operations identified in the received second request; and

generating a second response to the second client associated with the received second request, the second response comprising the results of the execution of the second instructions and a set of updated state information identifying a third state of the application as determined after the execution of the second instructions.

23. The computer-implemented method of claim 22, wherein the operations of the first request are executed by the application in a stateless mode and the operations of the second request are executed by the application in a stateful mode.

24. The computer-implemented method of claim 23, wherein the first client and the second client are identical.