Smart prefetching of data over a network

• US 7,975,025 B1
• Filed: 07/08/2008
• Issued: 07/05/2011
• Est. Priority Date: 07/08/2008
• Status: Expired due to Fees

• Current Assignee: F5 Networks, Inc. (F5 Incorporated)
• Original Assignee: F5 Networks, Inc. (F5 Incorporated)
• Inventors: Amdahl, Saxon Carl, Szabo, Paul I.
• Primary Examiner(s): Caldwell; Andrew
• Assistant Examiner(s): WILLIS, JONATHAN U
• Application Number:
  US12/169,366
• Time in Patent Office: 1,092 Days
• Field of Search: 370/230, 370/395.53, 705/51, 707/1, 707/9, 709/203, 709/213, 709/219, 709/225, 709/235, 709/202, 709/218, 711/118, 711/158, 711/163, 711/204, 715/738
• US Class Current: 709/218
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching

Abstract

A method, system, an apparatus are directed towards selectively prefetching content over a network. A request for a content object is received. The content object may comprise a link to another content object. A cachability measure for the link may be determined based on whether a plurality of previous requests for the link returned the other content object, an annotation in a link map, a probability of traversing the link, a network metric, or the like. A prefetchability measure for the link may be determined based on the cachability measure and/or another factor relating to the link. The other factor may be an annotation of the link indicating that caching the other content object will cause a related object to be uncachable. Based on the prefetchability measure, the other content object is selectively prefetched for subsequent provisioning and/or display.

Claims

1. A method operating on one or more network devices for providing content over a network, comprising:

receiving a request for a content object, wherein the content object includes at least one link to another content object;

determining a cachability measure for the at least one link based on a weighted sum of probabilities of a plurality of different cachability criteria;

determining a prefetchability measure for the at least one link based in part on the cachability measure and another factor associated with the other content object including lowering the prefetchability measure based on whether caching of the other content object causes a related third content object to be uncachable; and

if the prefetchability measure meets a threshold selected to indicate when content objects should be prefetched, prefetching the other content object for use by a client device, wherein prefetching is further based on a combination of an attribute of the request at an Open System Interconnection (OSI) layer 3 or above and an authorization to use the link by a user associated with the request.

2. The method of claim 1, wherein the plurality of different cachability criteria further comprises at least two of information within an annotation of a link map, a probability of the link being used, or an authorization of the user to access the link.

3. The method of claim 1, further comprising:

determining a caching behavior of the client device; and

configuring, based on the caching behavior, the prefetching to occur either on the client device or on a proxy interposed between the client device and a server device configured to provide the other content object.

4. The method of claim 1, wherein receiving the request for the other content object further comprises:

intercepting, on the client device, a request call of an operating system or an application interface, wherein the request call is for the content object.

5. A system for providing content over a network, comprising:

a prefetch cache configured for storing data and one or more computer readable instructions; and

one or more processors within one or more network devices having executing thereon;

a request manager configured to perform first actions, including;

receiving a request for a content object from a user; and

parsing the content object for a link to another content object; and

a prefetchability determiner configured to perform second actions, including;

determining a prefetchability measure based at least on an annotation of the link within a link map and lowering the prefetchability measure for the other content object based on whether caching of the other content object will cause a related content object to be uncachable; and

a prefetch manager configured to perform third actions, including;

if the prefetchability measure meets a threshold selected to indicate when content objects should be prefetched, prefetching the other content object for use at a client device, wherein prefetching is further based on a combination of an attribute of the request at an Open System Interconnection (OSI) layer 3 or above and an authorization to use the link by a user associated with the request.

6. The system of claim 5, further comprising:

a prioritization manager configured to perform fourth actions, including;

receiving an instruction to prefetch the other content object; and

determining whether to request the other content object if a priority associated with the content object is higher than another priority associated with at least one other content object managed by the prioritization manager.

7. The system of claim 5, further comprising:

a crawler interposed between the client device and a server for providing the other content object, configured to perform fourth actions, including;

storing a plurality of links in a link map based on a crawl of at least one web address;

receiving a determined probability of a subsequent link being used based on a usage of a prior link stored in the link map; and

enabling the prefetch cache to prefetch the other content object based on the probability.

8. The system of claim 5, further comprising:

a rule manager configured to determine whether to cache the other content object based on a rule that maps a Boolean expression of at least one of an Open System Interconnection (OSI) layer 3 or above attribute of the request and a caching action.

9. The system of claim 5, wherein the prefetchability determiner is interposed between the client device and a server configured to provide the other content object, and is further configured to send, over a tunnel on the network, a prefetch command to the prefetch cache.

10. The system of claim 5, wherein the annotation is based in part on whether a plurality of previous requests for the link returns the other content object.

11. A network device for providing content over a network, comprising:

a memory that stores data and instructions;

an input interface that receives requests and sends responses; and

a processor that performs actions embodied by at least a portion of the stored instructions, the actions comprising;

receiving a request for a content object, wherein the content object comprises a link to another content object;

determining a prefetchability measure based in part on whether the other content object is cachable and lowering the prefetchability measure for the other content object based on whether caching the other content object will cause another related content object to be uncachable; and

if the other content object is determined to be capable of being prefetched based on the prefetchability measure, selectively prefetching the other content object for display at a client device, wherein prefetching is further based on a combination of an attribute of the request at an Open System Interconnection (OSI) layer 3 or above and an authorization to use the link by a user associated with the request.

12. The network device of claim 11, wherein the other content object is prefetched into a browser cache of at the client device.

13. The network device of claim 11, wherein the prefetchability measure is based on whether the link is annotated as cachable in a link map.

14. The network device of claim 11, wherein prefetching further comprises:

if a browser behavior of the client device requesting the content object indicates client-side caching, sending a prefetch request to the client device to enable a browser on the client device to prefetch the other content object; and

if an authorization of the client device for the link indicates remote caching, caching the other content object at the network device, wherein the network device is interposed between the client device and a server configured to provide the other content object.

15. A non-transitory, machine-readable storage medium having machine-executable instructions stored thereon, which when executed by at least one processor within one or more network devices, causes the at least one processor to perform one or more actions, comprising:

receiving a request for a content object, wherein the content object comprises a link to another content object;

determining a prefetchability measure for the link based in part on whether caching the other content object causes a related object to be uncachable and whether a plurality of previous requests for the link returned the other content object, wherein the prefechability measure is lowered if the caching of the other content object causes a related object to be uncachable;

modifying the prefetchability measure based on a combination of an attribute of the request at an Open System Interconnection (OSI) layer 3 or above and an authorization to use the link by a user associated with the request; and

based on the prefetchability measure, selectively prefetching the other content object for use at a client device.

16. The non-transitory, machine-readable storage medium of claim 15, wherein the prefetchability measure is based on an annotation of the link in a link map, a network metric, or a probability of the link being requested.

17. The non-transitory, machine-readable storage medium of claim 15, wherein likelihood of selectively prefetching the other content object is modified based on whether the other content object includes dynamic content.

18. The non-transitory, machine-readable storage medium of claim 15, further comprising:

modifying the prefetchability measure based on a probability of the link being used by the client device requesting the content object after a usage of the requested content object.