Patent Publication Number: US-8996725-B2

Title: Programmatic redirect management

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Canadian Patent Application No.: CA2757816, filed 14 Nov. 2011, and all the benefits accruing therefrom under 35 U.S.C. §119, the contents of which in its entirety are herein incorporated by reference. 
     BACKGROUND 
     This disclosure relates generally to locating resources in a network in a data processing system and more specifically to programmatic redirect management for locating resources in a network in the data processing system. 
     When a web page of a website has an universal resource locator (URL) address changed, the website could lose valuable page ranking with search engines and affiliate links for the webpage. The loss may occur because the search engines and affiliates are pointing to the old URL address, which is now an invalid URL address. As a result, a typical search engine optimization solution handles changes to page URLs by returning what is referred to as a “301 redirect” to a new page, rather than showing a default “404 page not found” exception that would otherwise be presented to a site visitor. 
     An existing approach for a “301 redirect” situation is usually managed at a web server level, for example, using a configuration file, such as .htaccess, providing a mapping of old URLs to corresponding replacement URLs. A typical drawback of the existing approach is that it incurs manual overhead and is error prone. For example, when a URL address of a web page is changed, a technical person must manually update the web server configuration file to create a redirect rule for the changed page. An entire URL is typically mapped to a corresponding entire URL. In another example, a concept of a linked keyword may be used to represent a mapping of one element to a set of elements of an URL to provide a one-to-many mapping of elements. Accordingly, this leads to additional overhead and potential for mistakes since business users may change URLs and not inform technical administrators unintentionally leading to a “404 page not found” exception. 
     In another example, a large number of mappings are required for an online retail site with thousands or millions of products. When using traditional redirects having a hierarchical URL structure (containing many URL tokens), such as Furniture/Chairs/LoungeChairs, a change made to one of the parent tokens in the hierarchy, such as “Furniture”, requires technical administrators to create more elaborate redirect rules or multiple rules to remap all the child tokens to respective new locations from within the configuration file of the web server. When the same URL address needs to be changed several times, while keeping all previous rules still active, the problem is compounded. In the example, changing Furniture can potentially impact URLs of hundreds of associated products. A URL token is a keyword representing a portion of or a complete URL of a web page in a site. Each of the tokens is separated from another token in the URL by separator characters (for example, a slash in the examples). 
     Yet another potential issue with the common approach to  301  redirects is that a mapping solution is typically web server specific. A web server specific implementation requires a different solution for each web server, thus increasing maintenance and a potential for error. 
     Using existing approaches typically requires storing URL-to-URL mappings, which map the original URLs to redirected URLs. Creating and managing the URL-to-URL mappings requires prior knowledge of URL structures to create the pre-formed URL mapping rules. As the structure of any of original URLs change, there is a high maintenance cost associated with updating these mappings. 
     Using the online store with the existing approaches as an example, when a change is made from the “Furniture” category to a “SpringFurniture” category then a mapping is required such as:
         //Mapping Rule 1   From: http://www.yourstore.com/Furniture/ . . .   To: http://www.yourstore.com/SpringFurniture/ . . .       

     Also, when multiple URL structures containing the same URL keyword (Furniture in this example) are present then mappings for each of these structures is needed, as in:
         //Mapping Rule 1 From: http://www.yourstore.com/Furniture/ . . .   To: http://www.yourstore.com/SpringFurniture/ . . .   //Mapping Rule 2 From: http://www.yourstore.com/Sales/Furniture/ . . .   To: http://www.yourstore.com/Sales/SpringFurniture/ . . .   //Mapping Rule 3 From: http://www.yourstore.com/Sales/Outlet/Furniture/ . . .   To: http://www.yourstore.com/Sales/Outlet/SpringFurniture/ . . .       

     Further, when “Sales” is updated to become “Discounts” the complexity of the mappings continually increases with the number of updated structures. While the example is a simple illustration, with each additional change to a URL the system needed to maintain the redirect relationships becomes more complex very quickly. 
     SUMMARY 
     According to one embodiment, a computer-implemented process for programmatic redirect management receives a request containing a URL, identifies a set of keyword tokens in the URL of the request and a set of associated token IDs and determines whether a token ID in the set of associated token IDs is located in a data structure of a redirect registry. Responsive to a determination that the token ID in the set of associated token IDs is located in the redirect registry, the computer-implemented process performs token ID mapping for each token ID in the set of associated token IDs, updating statistics for each token ID mapped in the set of associated token IDs and responsive to a determination that token ID mapping is complete, composes a redirect URL. 
     According to another embodiment, a computer program product for programmatic redirect management, the computer program product including a computer readable storage medium having computer readable program code embedded therewith. The computer readable program code including computer readable program code configured for performing a method. The method including receiving a request containing a uniform resource locator, identifying a set of keyword tokens in the uniform resource locator of the request and a set of associated token identifications and determining whether a token identification in the set of associated token identifications is located in a data structure of a redirect registry. The method also includes performing token identification mapping for each token identification in the set of associated token identifications responsive to a determination that the token identification in the set of associated token identifications is located in the redirect registry. The method also includes updating statistics for each token identification mapped in the set of associated token identifications and determining whether token identification mapping is complete. The method further includes composing a redirect uniform resource locator responsive to a determination that token identification mapping is complete. 
     According to another embodiment, a system for programmatic redirect management, the system includes a processor unit configured to perform a method. The method includes receiving a request containing a uniform resource locator, identifying a set of keyword tokens in the uniform resource locator of the request and a set of associated token identifications and determining whether a token identification in the set of associated token identifications is located in a data structure of a redirect registry. The method also includes performing token identification mapping for each token identification in the set of associated token identifications responsive to a determination that the token identification in the set of associated token identifications is located in the redirect registry. The method further includes updating statistics for each token identification mapped in the set of associated token identifications and determining whether token identification mapping is complete. The method also includes composing a redirect uniform resource locator responsive to a determination that token identification mapping is complete. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in conjunction with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. 
         FIG. 1  is a block diagram of an exemplary network data processing system operable for various embodiments of the disclosure; 
         FIG. 2  is a block diagram of an exemplary data processing system operable for various embodiments of the disclosure; 
         FIG. 3  is a block diagram a redirect engine in accordance with one embodiment of the disclosure; 
         FIG. 4  is a block diagram of redirect registry portion of the redirect engine of  FIG. 3  in accordance with one embodiment of the disclosure; 
         FIG. 5  is a schematic diagram of a logical view of a redirect management process using the redirect engine of  FIG. 3  in accordance with one embodiment of the disclosure; 
         FIG. 6  is a flowchart of process for redirect management process representative of the logical view of  FIG. 5  in accordance with an illustrative embodiment of the disclosure; and 
         FIG. 7  is a flowchart of process for managing the redirect registry portion of the redirect engine of  FIG. 3  in accordance with an illustrative embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     With reference now to the figures and in particular with reference to  FIGS. 1-2 , exemplary diagrams of data processing environments are provided in which illustrative embodiments may be implemented. It should be appreciated that  FIGS. 1-2  are only exemplary and are not intended to assert or imply any limitation with regard to the environments in which different embodiments may be implemented. Many modifications to the depicted environments may be made. 
       FIG. 1  depicts a pictorial representation of a network of data processing systems in which illustrative embodiments may be implemented. Network data processing system  100  contains network  102 , which is the medium used to provide communications links between various devices and computers connected together within network data processing system  100 . Network  102  may include connections, such as wire, wireless communication links, or fiber optic cables. 
     In the depicted example, server  104  and server  106  connect to network  102  along with storage unit  108 . In addition, clients  110 ,  112 , and  114  connect to network  102 . Clients  110 ,  112 , and  114  may be, for example, personal computers or network computers. In the depicted example, server  104  provides data, such as boot files, operating system images, and applications to clients  110 ,  112 , and  114 . Clients  110 ,  112 , and  114  are clients to server  104  in this example. Network data processing system  100  may include additional servers, clients, and other devices not shown. 
     In the depicted example, network data processing system  100  is the Internet with network  102  representing a worldwide collection of networks and gateways that use the Transmission Control Protocol/Internet Protocol (TCP/IP) suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, governmental, educational and other computer systems that route data and messages. Of course, network data processing system  100  also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN).  FIG. 1  is intended as an example, and not as an architectural limitation for the different illustrative embodiments. 
     With reference to  FIG. 2  a block diagram of an exemplary data processing system operable for various embodiments of the disclosure is presented. In this illustrative example, data processing system  200  includes communications fabric  202 , which provides communications between processor unit  204 , memory  206 , persistent storage  208 , communications unit  210 , input/output (I/O) unit  212 , and display  214 . 
     Processor unit  204  serves to execute instructions for software that may be loaded into memory  206 . Processor unit  204  may be a set of one or more processors or may be a multi-processor core, depending on the particular implementation. Further, processor unit  204  may be implemented using one or more heterogeneous processor systems in which a main processor is present with secondary processors on a single chip. As another illustrative example, processor unit  204  may be a symmetric multi-processor system containing multiple processors of the same type. 
     Memory  206  and persistent storage  208  are examples of storage devices  216 . A storage device is any piece of hardware that is capable of storing information, such as, for example without limitation, data, program code in functional form, and/or other suitable information either on a temporary basis and/or a permanent basis. Memory  206 , in these examples, may be, for example, a random access memory or any other suitable volatile or non-volatile storage device. Persistent storage  208  may take various forms depending on the particular implementation. For example, persistent storage  208  may contain one or more components or devices. For example, persistent storage  208  may be a hard drive, a flash memory, a rewritable optical disk, a rewritable magnetic tape, or some combination of the above. The media used by persistent storage  208  also may be removable. For example, a removable hard drive may be used for persistent storage  208 . 
     Communications unit  210 , in these examples, provides for communications with other data processing systems or devices. In these examples, communications unit  210  is a network interface card. Communications unit  210  may provide communications through the use of either or both physical and wireless communications links. 
     Input/output unit  212  allows for input and output of data with other devices that may be connected to data processing system  200 . For example, input/output unit  212  may provide a connection for user input through a keyboard, a mouse, and/or some other suitable input device. Further, input/output unit  212  may send output to a printer. Display  214  provides a mechanism to display information to a user. 
     Instructions for the operating system, applications and/or programs may be located in storage devices  216 , which are in communication with processor unit  204  through communications fabric  202 . In these illustrative examples the instructions are in a functional form on persistent storage  208 . These instructions may be loaded into memory  206  for execution by processor unit  204 . The processes of the different embodiments may be performed by processor unit  204  using computer-implemented instructions, which may be located in a memory, such as memory  206 . 
     These instructions are referred to as program code, computer usable program code, or computer readable program code that may be read and executed by a processor in processor unit  204 . The program code in the different embodiments may be embodied on different physical or tangible computer readable storage media, such as memory  206  or persistent storage  208 . 
     Program code  218  is located in a functional form on computer readable storage media  220  that is selectively removable and may be loaded onto or transferred to data processing system  200  for execution by processor unit  204 . Program code  218  and computer readable storage media  220  form computer program product  222  in these examples. In one example, computer readable storage media  220  may be in a tangible form, such as, for example, an optical or magnetic disc that is inserted or placed into a drive or other device that is part of persistent storage  208  for transfer onto a storage device, such as a hard drive that is part of persistent storage  208 . In a tangible form, computer readable storage media  220  also may take the form of a persistent storage, such as a hard drive, a thumb drive, or a flash memory that is connected to data processing system  200 . The tangible form of computer readable storage media  220  is also referred to as computer recordable storage media. In some instances, computer readable storage media  220  may not be removable. 
     Alternatively, program code  218  may be transferred to data processing system  200  from computer readable storage media  220  through a communications link to communications unit  210  and/or through a connection to input/output unit  212 . The communications link and/or the connection may be physical or wireless in the illustrative examples. The computer readable media also may take the form of non-tangible media, such as communications links or wireless transmissions containing the program code. 
     In some illustrative embodiments, program code  218  may be downloaded over a network to persistent storage  208  from another device or data processing system for use within data processing system  200 . For instance, program code stored in a computer readable storage medium in a server data processing system may be downloaded over a network from the server to data processing system  200 . The data processing system providing program code  218  may be a server computer, a client computer, or some other device capable of storing and transmitting program code  218 . 
     Using data processing system  200  of  FIG. 2  as an example, a computer-implemented process for programmatic redirect management is presented. The computer-implemented process receives an input URL that is analyzed to identify inactive URL keyword tokens. The inactive URL keyword tokens are replaced with the appropriate redirect tokens to carry out the URL request. 
     Processor unit  204  receives a request containing a URL using communications unit  210 , input/output unit  212 , display  214  or storage devices  216 , and identifies a set of keyword tokens in the URL of the request and a set of associated token IDs. The processor unit  204  then determines whether a token ID in the set of associated token IDs is located in a data structure of a redirect registry, maintained in storage devices  216  of the data processing or another system such as that including network data processing  100  of  FIG. 1 . Responsive to a determination that the token ID in the set of associated token IDs is located in the redirect registry, processor unit  204  performs token ID mapping for each token ID in the set of associated token IDs, updating statistics for each token ID mapped in the set of associated token IDs and responsive to a determination that token ID mapping is complete, composes a redirect URL. 
     Embodiments of the disclosed process typically enable “301 redirects” to be generated programmatically within an application layer upon a change of a URL address by a business user. Using a framework in an embodiment of the disclosed process provides a capability to automatically generate and store the redirect rules in a data structure, such as a database, rather than require a technical administrator to manually edit a web server configuration file as typically performed in previous solutions. An embodiment of the disclosed process is web server independent, thus providing flexibility to typically be implemented on any platform or configuration. 
     The number of URL keyword tokens changed, or the number of changes made to a URL keyword token, is typically not an issue because embodiments of the disclosed process generate token to token mapping rules rather than creating an exhaustive list of rules for all possible URL address combinations, keeping a footprint of a supporting data structure small. Using a prior approach, for example, typically required when a token of “Furniture” in a hierarchical URL structure of Furniture/Chairs/LoungeChairs was changed, lead to creation of hundreds of mappings for all the products under the “Furniture.” In another example of a prior approach fewer mappings were created but the mappings were more complex. However, using a framework in an embodiment of the disclosed process in the above example only a single mapping is needed between “Furniture” and a respective replacement token, which significantly reduces the number of mappings needed and accordingly typically improves performance. 
     With reference to  FIG. 3 , a redirect engine in accordance with one embodiment of the disclosure is presented. Redirect engine  300  is an example of a redirect processing system which may be implemented on and leverage support of a data processing such as network data processing  100  of  FIG. 1  or data processing system  200  of  FIG. 2  in accordance with the disclosure. 
     Redirect engine  300  includes a number of components including registry builder  302 , registry data structure  304 , parser  306 , composer  308  and entry locator  310  to provide a capability of programmatic redirect management. Redirect engine  300  as shown with representative functional elements, may be implemented as a combination of discrete functional elements or a monolithic set of logic without limitation to the capability provided. URL token registry  312  is not part of redirect engine  300  but is used by redirect engine  300  as a service and is described more fully in reference to  FIG. 4 . 
     Registry builder  302  provides a capability to receive change information associated with URL elements, which have been tokenized and generates entries in registry data structure  304 . Tokenization is a known existing process performed where a URL is separated into a set of respective URL elements. Each of the identified URL elements is assigned a unique token ID corresponding to an associated keyword. Tokenization of URLs is performed to provide input to redirect engine  300 , however registry builder  302  only uses a token ID portion of the information maintained by URL token registry  312 . 
     Each entry of registry data structure  304  provides a mapping between an original URL token and a corresponding replacement token. A sequence of mappings may be traversed to create a final mapping from an original URL token and a final replacement token. Each token ID in registry data structure  304  is associated with statistics including a “last used” timestamp and a “use count” value representative of the number of times a token ID has been referenced. Statistics are used to manage the relevance of entries maintained in registry data structure  304 . For example, a use count may be used to determine whether to migrate an entry into or out of cache of registry entries. 
     Parser  306  provides a capability to receive an original URL and identify a pattern associated with the original URL to identify individual elements in the form of keywords to identify a set of keywords, each of which is associated with a corresponding unique token ID. A parsed URL provides a set of token IDs, resulting from a lookup in URL token registry  312 , which is representative of the URL provided. Each token in the set of token IDs is used by entry locator  310  to determine whether an exact match is found within registry data structure  304 . When a match is found, a corresponding token ID of a respective pair of token IDs including the entry is used, unless in a subsequent search within registry data structure  304  another mapping is found using the previously mapped token ID until all mapping is complete. 
     Composer  308  provides a capability to resolve a resultant string of token IDs into a redirect URL that is processed as in the original request. 
     With reference to  FIG. 4 , it is a block diagram of logical view of a redirect registry portion of the redirect engine of  FIG. 3  in accordance with one embodiment of the disclosure. Redirect registry  422  is an example of a redirect registry in accordance with the disclosure. 
     Logical view  400  includes a portion containing URL token registry  402  and a portion containing redirect registry  422 . URL token registry  402  is not part of redirect engine  300  of  FIG. 3  but supports processing using redirect engine  300  of  FIG. 3  in conjunction with redirect registry  422 . 
     In the example provided, the data structure representative of URL token registry  402  may be viewed as a table of entries. Columns of the table in this instance represent token IDs and associated keywords as in Token ID  404  and Keyword  406  respectively. Each row in the table is then a pairing of token ID with a respective keyword. The token IDs are illustrated as a set of token IDs  408 ,  410 ,  412 ,  414 ,  416 ,  418  and  420  representing unique token IDs  1 ,  2 ,  3 ,  4 ,  5 ,  6  and  7  respectively. The token keywords are illustrated as a set of keywords  426 ,  428 ,  430 ,  432 ,  434 ,  436  and  438  representing keywords of “en”, “Furniture,” “LoungeChairs,” “EliteLoungeChair,” “SprinFurniture,” “PremiumLoungeChair” and “NewFurniture” respectively. URL token registry  402  is previously constructed by parsing URLs defined for use with a web based application using a known technique (outside the scope of this disclosure). 
     Redirect registry  422  may be viewed as data structure in a similar manner to a construct of URL token registry  402 . Redirect registry  422  is, however, designed to be more lightweight than URL token registry  402  because redirect registry  422  contains only change data reflecting changes from old URL keywords to new URL keywords. For example, the column of Token ID  404  of redirect registry  422  typically contains a relatively small but active subset of token IDs from URL token registry  402  representing inactive token portions of URLs previously described in URL token registry  402 . New token ID  424  represents token IDs replacing the corresponding entry in Token ID  404  of redirect registry  422 . 
     For example token IDs  410 ,  414  and  416  of redirect registry  422  are replaced by corresponding new token IDs of  416 ,  418  and  432  respectively using redirect registry  422 . From the example, using redirect registry  422  token ID  410  (value of 2) is mapped to new token ID  416  (value of 5), which is later mapped to new token ID  420  (value of 7). 
     With reference to  FIG. 5  a schematic diagram of a logical view of a redirect management process using the redirect engine of  FIG. 3  in accordance with one embodiment of the disclosure is presented. Process  500  is an example using URL token registry  402  and redirect registry  422  both of  FIG. 4  (shown here for completeness) to transform input URL  502  into redirect URL  504  of redirect engine  300  of  FIG. 3 . 
     Find token IDs  506 , a sub-process, using keyword elements of keywords  426 ,  428 ,  430  and  432  of  FIG. 4  found in parsing input URL  502 , performs a lookup of URL token registry  402  of  FIG. 4 . Having found keywords in the set of keywords, token IDs  408 ,  410 ,  412  and  414  associated with the respective keywords are obtained. 
     Find mapping between the old token ID and the new token ID  508  is a sub-process, which locates corresponding entries in redirect registry  422  of  FIG. 4  given an old token ID. For example token ID  408  is an identify mapping because there is no entry for redirect (similar to token ID  412  mapping). In contrast, token ID  410  maps initially to token ID  416  and subsequently to token ID  420  represented in can have multiple mappings  510  which is an iterative sub-process to resolve a sequence of mappings using a related set of correspondence pairings in which success mappings are required to arrive at a final new token ID. A typical single step mapping is represented in the mapping of token ID  414  to token ID  418 . 
     Find URL keywords from URL token registry  512  is a sub-process that performs a lookup in URL token registry  402  of  FIG. 4 . The keywords retrieved by lookup are then composed to form redirect URL  504  inclusive of the replacement keywords. 
     With reference to  FIG. 6  a flowchart of process for redirect management process representative of the logical view of  FIG. 5  in accordance with an illustrative embodiment of the disclosure is presented. Process  600  is an example of a process using redirect engine  300  of  FIG. 3  to transform a URL containing inactive portions into a redirect URL containing portions as a replacement for the input URL containing inactive portions. 
     Process  600  starts (block  602 ) and receives a request containing a URL (block  604 ). The URL of the request, for example, is directed toward a product representative of http://www.sampleurl.com/en/Furniture/LoungeChairs/EliteLoungeChair. However, in this example the initial URL is changed to direct a user toward http://www.sampleurl.com/en/Furniture/LoungeChairs/PremiumLoungeChair. Using an embodiment of the disclosed process enables site visitors to use the original URL address that may be book marked, or that search engines may have indexed. Embodiments of process  600  provide a capability to programmatically remap the old URL address to the new URL address thereby preserving the rank of the web page in search engines. When a business user changes the EliteLoungeChair keyword of the example to PremiumLoungeChair, process  600  creates a redirect mapping rule between the old URL keyword EliteLoungeChair and the new URL keyword PremiumLoungeChair. 
     Process  600  identifies a set of keyword tokens in the received URL and a set of associated token IDs (for example, using URL token registry  402  as shown in  FIG. 5 ) (block  606 ). When the input URL http://www.sampleurl.com/en/Furniture/LoungeChairs/EliteLoungeChair is requested by a site visitor, process  600  determines whether a token ID in the set of associated token IDs is located in a redirect registry (block  608 ). Process  600  performs a lookup in the redirect registry for a redirect rule associated with any of the token IDs input. Responsive to a determination that a token ID in the set of associated token IDs is not located in a redirect registry, process  600  initiates the URL (block  618 ). Process  600  loops back to block  602  to await a request as before. 
     Responsive to a determination that a token ID in the set of associated token IDs is located in a redirect registry, process  600  performs token ID mapping for each token ID in the set of associated token IDs (block  610 ). Token ID mapping replaces the old URL token IDs from the URL address of the request with appropriate redirected URL token IDs to carry out the request. Process  600  updates statistics for each token ID in the set of associated token IDs (block  612 ). Statistics are updated continually to provide information to aid in maintaining relevancy and efficiency of the redirect registry. Statistics include “last used” (timestamp driven) and “use count” (number of references) used to preen the registry as well as for cache management. 
     Process  600  determines whether token ID mapping is complete (block  614 ). In a more complex example multiple URL keywords are changed in the received URL. For the remaining products under a modified category, process  600  does not need to create redirect mappings because the mapping is automatically handled at a parent category URL keyword level. 
     Assume in the previous example, that the business user also changed the URL keyword for the furniture category from “Furniture” to “HomeFurnishing”. Process  600  creates a redirect mapping between the old URL keyword token Furniture and the new URL keyword token of “HomeFurnishing”. A bookmarked or search engine indexed URL of http://www.sampleurl.com/en/Furniture/LoungeChairs/EliteLoungeChair is still used and process  600  resolves the new URL address as http://www.sampleurl.com/en/HomeFurnishing/LoungeChairs/PremiumLoungeChair. In the example the category URL redirect mapping and the product URL redirect mapping are performed by process  600  when a site visitor navigates to one of the original product URLs. In this way site visitors continue to navigate to the original URLs indexed by search engines but are forwarded to the new URLs programmatically. 
     When a determination is made that token ID mapping is not complete process  600  loops back to block  610  to repeat mapping until no input token IDs have an associated redirect token ID. When a determination is made that token ID mapping is complete, process  600  finds a URL keyword token name corresponding to each token ID and replaces all the original input keyword tokens with the redirect tokens in the URL to compose a redirect URL (using mapped token IDs) using a URL token registry (block  616 ). Process  600  performs a “301 redirect” request against the web server using the new redirected URL to initiate the URL (block  618 ) and loops back to perform block  602  as before. 
     In another example of an end-to-end solution using an embodiment of the disclosed process, a shopper invokes a web-based search engine to search for a particular item of interest in the form of a “red espresso machine.” The shopper is responded with a number of search results, one of which is for an espresso machine at a specific store. The link provided in the search result for the espresso machine is as follows:
         http://www.sampleurl.com/Kitchenware/Appliances/CoffeeMakers/espresso-red-SKU9019.       

     The shopper selects the link for the red espresso machine at the store from search results. The shopper does not realize a search engine optimization specialist for the store has changed the URL for this red espresso machine, even though search engine is still showing the original URL (because the search engine has not re-indexed the page). As a result, the red espresso machine is now located at the following URL:
         http://www.sampleurl.com/KitchenwareSales/Appliances/EspressoMachines/Red Espress Machine.       

     Using an embodiment of the disclosed process when the shopper selects the link for the red espresso machine, the original URL is taken into the system as:
         http://www.sampleurl.com/Kitchenware/Appliances/CoffeeMakers/espresso-red-SKU9019
 
and processed. The pattern of the URL provided is identified and recorded. This pattern is then used to decompose the URL into respective most basic parts, keyword portions, of the URL including Kitchenware, Appliances, CoffeeMakers and espresso-red-SKU9019. A search is performed within the system of the embodiment to find replacement URL keywords for the previously identified portions to yield pairings of Kitchenware-&gt;KitchenwareSales, Appliances-&gt;no replacement, CoffeeMakers-&gt;EspressoMachines and espresso-red-SKU9019-&gt;espresso-red-&gt;RedEspressoMachine.
       

     As shown, embodiments of the disclosed process find a single replacement keyword, no replacement at all, or a chain of replacements where multiple changes have been made to the same URL keyword. Existing approaches are typically more difficult to manage a growing set of redirect rules including multiple changes to a single URL, particularly when there are multiple changes to a single URL keyword within the URL as in the example. Chains of keyword-to-keyword redirects can be processed intelligently by looking up chain ends programmatically rather then processing each redirect in the chain separately. 
     The new URL is recomposed by replacing the original URL keywords with corresponding final replacements based on the URL pattern identified to provide a redirect URL of http://www.sampleurl.com/KitchenwareSales/Appliances/EspressoMachines/RedEspressoMachine. The new URL is now available to the runtime in order to perform a “301 redirect.” Using an embodiment of the disclosed process enables a shopper to be redirected to a correct URL for the red espresso machine without storing any mapping between the original URL and the redirected URL. 
     With reference to  FIG. 7  a flowchart of a process for managing the redirect registry portion of the redirect engine of  FIG. 3  is generally shown in accordance with an illustrative embodiment of the disclosure. Process  700  is an example of a process used to add and remove entries in redirect registry  300  of  FIG. 3 . Process  700  is also used as a cache management process for cached entries redirect registry  300  of  FIG. 3 . 
     Process  700  starts (block  702 ) and determines whether a request is for a new redirect rule (block  704 ). Responsive to a determination the request is for a new redirect rule process  700  receives URL change information including an old token ID and a corresponding replacement token ID (block  706 ). The change information is made available by a change process external to process  700  (outside the scope of the current disclosure). For example, a business user, using a suitable tool, may input an original URL and provide an update in the form of a changed keyword. The unique IDs of the old keyword and the new keyword are made available by the tool to a process such as process  700 . 
     Process  700  generates an entry for the new redirect rule containing a correspondence mapping of the old token ID to a replacement token ID forming a correspondence pair in the redirect registry (block  708 ). The correspondence pair is representative of the change made between the old keyword and the new keyword. Process  700  loops back to block  702  awaiting a request. Using process  700  requires no system down time when new redirect mappings are created (no server restarts are required). 
     Responsive to a determination the request is not for a new redirect rule process  700  determines whether a “last used” statistic of a redirect rule entry exceeds a predetermined threshold (block  710 ). For example, when a “last used” date of an entry exceeds a predetermined time (for example a timestamp) value. 
     Responsive to a determination the “last used” statistic of a redirect rule entry exceeds a predetermined threshold process  700  and deletes an identified rule entry from the redirect registry (block  712 ). The identified rule entry is an entry containing a correspondence pair in which a “last used” statistic of one or both entries exceeds a predetermined threshold. Process  700  determines whether the identified rule entry is cached (block  714 ). Responsive to a determination the identified rule entry is cached, process  700  deletes the identified rule entry from a cache (block  716 ) and loops back to block  702  as before. Responsive to a determination that the identified rule entry is not cached process  700  loops back to perform block  718 . Caching of a redirect registry or entries is a performance consideration. The redirect rules are added to a data cache to reduce a need to perform a database lookup the next time the same redirect rules are used. When a redirect rule is not used in a configurable amount of time then it is deleted from the cache and the database, thereby reducing the database footprint automatically. Caching the mapping between the original URLs and redirected URLs avoids using the token identification process again. 
     Responsive to a determination that the “last used” statistic of a redirect rule entry does not exceed a predetermined threshold, process  700  determines whether a “use count” statistic of a redirect rule entry exceeds a predetermined threshold (block  718 ). Responsive to a determination the “use count” statistic of a redirect rule entry exceeds a predetermined threshold, process  700  adds the identified rule to the cache (block  720 ) and loops back to perform block  702  as before. Responsive to a determination the “use count” statistic of a redirect rule entry does not exceed a predetermined threshold, process  700  loops back to perform block  702  as before. 
     Using an embodiment of the disclosed process, URL mappings are not stored; rather URL mappings are computed on the fly in a runtime. Changes between URL keywords, the smallest elements of a URL, are saved in a data structure of the redirect registry for future use. Using the previous example, only a single change between “Furniture” and “SpringFurniture” is saved rather than a map including a complete set of URL definitions. 
     The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that, in some alternative implementations, the functions noted in the block might occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. 
     but is not limited to firmware, resident software, microcode, and other software media that may be recognized by one skilled in the art. 
     It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such as a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communications links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The computer readable media may take the form of coded formats that are decoded for actual use in a particular data processing system. 
     A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. 
     Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers. 
     Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modems, and Ethernet cards are just a few of the currently available types of network adapters. 
     Although an illustrative implementation of one or more embodiments is provided below, the disclosed systems and/or methods may be implemented using any number of techniques. This disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims along with their full scope of equivalents. 
     As will be appreciated by one skilled in the art, aspects of the present disclosure may be embodied as a system, method or computer program product. Accordingly, aspects of the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module,” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. 
     Any combination of one or more computer-readable medium(s) may be utilized. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CDROM), an optical storage device, or a magnetic storage device or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. 
     A computer-readable signal medium may include a propagated data signal with the computer-readable program code embodied therein, for example, either in baseband or as part of a carrier wave. Such a propagated signal may take a variety of forms, including but not limited to electro-magnetic, optical or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. 
     Program code embodied on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wire line, optical fiber cable, RF, etc., or any suitable combination of the foregoing. 
     Computer program code for carrying out operations for aspects of the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as Java™, Smalltalk, C++, or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
     Aspects of the present disclosure are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus, (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. 
     These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     These computer program instructions may also be stored in a computer readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.