System and method for performing granular invalidation of cached dynamically generated objects in a data communication network

• US 20070156966A1
• Filed: 12/30/2005
• Published: 07/05/2007
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Kailash, Kailash, Sinha, Rajiv, Kumar, Anil, Soni, Ajay, Khemani, Prakash, Annamalaisami, Saravana, Sundarrajan, Prabakar, Bhushan KR, Bharat
• Granted Patent: US 8,301,839 B2
• Time in Patent Office: Days
• US Class Current: 711/133
• CPC Class Codes: G06F 12/0808 with cache invalidating means G06F12/0815 takes precedence
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 2212/2022 Flash memory

Abstract

The present invention is directed towards a method and system for providing granular timed invalidation of dynamically generated objects stored in a cache. The techniques of the present invention incorporates the ability to configure the expiration time of objects stored by the cache to fine granular time intervals, such as the granularity of time intervals provided by a packet processing timer of a packet processing engine. As such, the present invention can cache objects with expiry times down to very small intervals of time. This characteristic is referred to as “invalidation granularity.” By providing this fine granularity in expiry time, the cache of the present invention can cache and serve objects that frequently change, sometimes even many times within a second. One technique is to leverage the packet processing timers used by the device of the present invention that are able operate at time increments on the order of milliseconds to permit invalidation or expiry granularity down to 10 ms or less.

Claims

1. In a packet processing engine of a device, the packet processing engine processing network packets comprising at least one dynamically generated object and storing the at least one dynamically generated object in a cache, a method for invalidating a cached dynamically generated object in the cache responsive to a signal of a packet processing timer, the method comprising the steps of:

(a) receiving a first signal from a packet processing timer to process a network packet;

(b) processing the network packet responsive to the signal; and

(c) transmitting a second signal to a cache indicating a cached dynamically generated object is invalid.

2. The method of claim 1, comprising providing, by the second signal, an invalidation command to invalidate the cached dynamically generated object.

3. The method of claim 1, comprising providing, by the second signal, an expiration of an expiry of the cached dynamically generated object

4. The method of claim 1, wherein step (c) is performed during processing of the network packet

5. The method of claim 1, wherein step (c) is performed upon completion of processing of the network packet.

6. The method of claim 1, comprising operating the packet processing timer at a time increment of one or more milliseconds.

7. The method of claim 1, comprising operating the packet processing timer at a time increment to invalidate an object stored in cache at an expiry time of one of equal to or less than 10 milliseconds.

8. The method of claim 1, comprising marking, by the cache, the cached dynamically generated object as invalid.

9. The method of claim 1, wherein the device comprises one of the following:

a bridge, a router, a switch, and a SSL VPN device.

10. The method of claim 1, comprising operating one of the cache, the packet processing engine, or the packet processing timer in a kernel space of the device.

11. The method of claim 1, comprising providing, via the packet processing timer, a time interval for expiry of the cached dynamically generated object one of less than or equal to a duration of time to dynamically generate and serve the dynamically generated object from an originating server.

12. The method of claim 1, comprising transmitting from an originating server the network packet comprising dynamically generated object.

13. The method of claim 1, wherein the dynamically generated object is identified as not cacheable.

14. A device for invalidating a cached dynamically generated object responsive to a signal of a packet processing timer, the device processing network packets comprising at least one dynamically generated object and storing the at least one dynamically generated object in a cache, the device comprising:

a packet processing timer generating a first signal;

a packet processing engine, in communication with the packet processing timer, processing the network packet responsive to receipt of the first signal of the packet processing timer; and

a cache, in communication with the packet processing engine, having a dynamically generated object cached in a storage element, the cache receiving a second signal from the packet processing engine indicating the cached dynamically generated object is invalid.

15. The device of claim 14, wherein the second signal comprises an invalidation command to invalidate the cached dynamically generated object.

16. The device of claim 14, wherein the second signal comprises an expiration of an expiry of the cached dynamically generated object.

17. The device of claim 14, wherein the packet processing engine transmits the second signal to the cache during processing of the network packet by the packet processing engine.

18. The device of claim 14, wherein the packet processing engine transmits the second signal to the cache upon completion of processing of the network packet.

19. The device of claim 14, wherein the packet processing timer operates at a time interval of one or more milliseconds.

20. The device of claim 14, wherein the packet processing timer operates at a time interval to trigger the second signal to the cache to invalidate the cached object at a first time interval of one of equal to or less than 10 milliseconds.

21. The device of claim 14, wherein the device comprises one of the following:

a bridge, a router, a switch, and a SSL VPN device.

22. The device of claim 14, wherein one of the cache, the packet processing engine, or the packet processing timer operates in a kernel space of the device.

23. The device of claim 14, wherein the packet processing timer provides a time interval for expiry of the cached dynamically generated object one of less than or equal to a duration of time to dynamically generate and serve the dynamically generated object from an originating server.

24. The device of claim 14, wherein an originating server transits the network packet comprising the dynamically generated objected.

25. The device of claim 14, wherein the dynamically generated object is not identified as cacheable.