Patent Publication Number: US-8996702-B2

Title: Method, system, and computer program product for routing sessions to a specific URL in a multi-site environment

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to computing systems, and more specifically relates to a method, system, and computer program product for routing sessions to a specific Uniform Resource Locator (URL) in a multi-site environment. 
     BACKGROUND OF THE INVENTION 
     In a multi-site “high availability” environment, routing a request to a particular site within the multi-site environment can be problematic. There are many factors that need to be designed into a solution. The solution must address balancing requests between sites, and must be able to fail over to a working site if a site is unavailable. The solution must also have the flexibility to allow a developer to generate robust and dynamic URL strings. There are no known solutions to this problem. 
     An illustrative high availability multi-site environment  10  is depicted in  FIG. 1 . The multi-site environment  10  includes a plurality of substantially identical, independent sites  12 A,  12 B, . . . ,  12 N, each including a plurality of servers  14 . 
     At any given time, a browser session  16  may be directed to a server  14  on any of the sites  12 A,  12 B, . . . ,  12 N in the multi-site environment  10  available at that time. For example, on a first day a user&#39;s browser session  16  may be directed to a server  14  at site  12 A, while on the next day the user&#39;s browser session  16  may be directed to a server  14  at site  12 B. This is done without the knowledge of the user. This can create a problem when, for example, two or more users at different sites  12 A,  12 B, . . . ,  12 N wish to collaborate using a application (e.g., a chat application) that is unaware of the existence of other sites  12 A,  12 B, . . . ,  12 N in the multi-site environment  10 . One problem to be solved, therefore, is how to route a plurality of independent browser sessions  16  to the same server  14  at the same site  12 A,  12 B, . . . ,  12 N in the multi-site environment  10 . 
     SUMMARY OF THE INVENTION 
     In general, the present invention provides a method, system, and computer program product for routing sessions to a specific Uniform Resource Locator (URL) in a multi-site environment. 
     The present invention provides a set of URL helper classes that generate a URL based on an array of ordered servers and associated information including the protocol, port, and path. Using the list of possible servers, a valid URL is determined by looping through the list until a successful connection can be found. Once a valid connection has been found, variables and their values are appended to the URL string. The URL helper classes allow a developer to define both global and runtime variables. The URL can be pushed to one or more users to route a browser session to a particular server at a particular site in a multi-site environment. 
     A first aspect of the present invention is directed to a method for routing sessions to a specific URL in a multi-site environment, comprising: providing an ordered list of servers in the multi-site environment; receiving a session request submitted by a user; looping through the ordered list of servers until a valid URL is found; and redirecting the session request to the server in the multi-site environment specified by the valid URL. 
     A second aspect of the present invention is directed to a system for routing sessions to a specific URL in a multi-site environment, comprising: a system for providing an ordered list of servers in the multi-site environment; a system for receiving a session request submitted by a user; a system for looping through the ordered list of servers until a valid URL is found; and a system for redirecting the session request to the server in the multi-site environment specified by the valid URL. 
     A third aspect of the present invention is directed to a program product stored on a computer readable medium for routing sessions to a specific URL in a multi-site environment, the computer readable medium comprising program code for performing the following steps: providing an ordered list of servers in the multi-site environment; receiving a session request submitted by a user; looping through the ordered list of servers until a valid URL is found; and redirecting the session request to the server in the multi-site environment specified by the valid URL. 
     A fourth aspect of the present invention is directed to a method for deploying an application for routing sessions to a specific URL in a multi-site environment, comprising: providing a computer infrastructure being operable to: provide an ordered list of servers in the multi-site environment; receive a session request submitted by a user; loop through the ordered list of servers until a valid URL is found; and redirect the session request to the server in the multi-site environment specified by the valid URL. 
     A fifth aspect of the present invention is directed to computer software for routing sessions to a specific URL in a multi-site environment, the computer software comprising instructions to cause a computer system to perform the following functions: provide an ordered list of servers in the multi-site environment; receive a session request submitted by a user; loop through the ordered list of servers until a valid URL is found; and redirect the session request to the server in the multi-site environment specified by the valid URL. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings in which: 
         FIG. 1  depicts an illustrative high availability multi-site environment. 
         FIG. 2  depicts a flow diagram of a method for routing sessions to a specific URL in a multi-site environment in accordance with an embodiment of the present invention. 
         FIG. 3  depicts an illustrative high availability multi-site environment in accordance with an embodiment of the present invention. 
         FIG. 4  depicts an illustrative computer system for implementing embodiment(s) of the present invention. 
     
    
    
     The drawings are merely schematic representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements. 
     BEST MODE FOR CARRYING OUT THE INVENTION 
     The present invention provides a method, system, and computer program product for routing sessions to a specific Uniform Resource Locator (URL) in a multi-site environment. 
     A flow diagram of a method for routing sessions to a specific URL in a multi-site environment in accordance with an embodiment of the present invention is depicted in  FIG. 2 . The flow diagram will be described with reference to the illustrative multi-site environment  20  depicted in  FIG. 3 . The multi-site environment  20  includes a plurality (three in this example) of substantially identical, independent sites  22 A,  22 B,  22 C, each including a plurality of servers  24 . 
     In step S 1 , an ordered list  26  of servers  24  in the multi-site environment  20  is generated. First, each site  22 A,  22 B,  22 C is prioritized. For example, site  22 A can be set as the “primary” site, site  22 B can be set as the “secondary” site, and site  22 C can be set as the “tertiary” site. The sites can be prioritized based on predetermined criteria or in a random manner. For example, IM sessions can be grouped by topic to parallel SME (Subject Matter Experts) groups: Windows, Linux, AIX, etc. The priority of each group can be set based on the physical location of the central SME group to the hosting site. For instance, assume that the central location for a Windows SME group is Austin, Tex. and that hosting sites are located in Boulder, Colo., Research Triangle Park (RTP), N.C., and St. Louis, Mo. Since St. Louis is physically closest to Austin, it can be set as the “primary” site. Similarly, since Boulder is the next closest site and RTP is the farthest away, Boulder can be set as the “secondary” site and RTP can be set as the “tertiary” site. This prioritization scheme is based on the assumption that Austin would get better performance, even though it may be small, if their IM communications were routed to the site closest to them. 
     The servers  24  within each prioritized site  22 A,  22 B,  22 C are each assigned a different task. For example, one server  24  may be used to provide database services, one server  24  may be used to render static content, one server  24  may be used to provide portlet services, one server  24  may be used to provide Java servlet services, and one server  24  may be used to provide IM services. In order to maintain high availability, each “server”  24  can be implemented using a cluster comprising a plurality of individual servers. Clustering makes the individual servers behave as a single server regardless of where the request is actually being completed. The ordered list  26  of servers is provided to each site  22 A,  22 B,  22 C in the multi-site environment  20 . In this example, server # 3   24  in each site  22 A,  22 B,  22 C is an IM server. 
     Each site  22 A,  22 B,  22 C in the multi-site environment  20  includes a session routing portlet  28 . The session routing portlet  28  includes a URL helper service  30 . The URL helper service  30  includes a set of URL helper classes that are configured to generate a URL based on the ordered list  26  of servers  24  and associated information including the protocol, port, and path. 
     In step S 2 , in response to the receipt of an instant messaging (IM) session request  32 A at one of the sites  22 A,  22 B,  22 C in the multi-site environment  20  (site  22 B in this example), the session routing portlet  28  at site  22 B requests a URL from the URL helper service  30  and passes initialization parameters comprising the protocol, path, and port (these parameters are static—only the name of the server  24  changes). In general, all of the parameters could be different. In step S 3 , the URL helper service  30  builds and checks a URL by looping (step S 4 ) through the ordered list  26  of servers  24 , from highest priority to lowest, until a valid URL (i.e., a valid connection) is found. Once a valid URL is found, variables and their values may be appended to the URL string. In this example, it is assumed that the IM server (i.e., server # 3   24  at the primary site  22 A) is not up and that the first valid URL for an IM server is found at server  24  # 3  at the secondary site  22 B. 
     In step S 5 , the URL helper service  30  appends global variables to the valid URL found in step S 4 . The global variables comprise pieces of data which are passed to all of the places where URLs are built. Login information, which is always sent to the IM server, is an example of a global variable. This data is moved into the global variable section and maintained in one place. For example, given the following URL: http://servername/path:port?user=userID&amp;special=special, global variables are used to fill in the common data, such as user ID, while specific variables are used for things which are specific to this instance of the connection. 
     In step S 6 , the URL helper service  30  appends runtime variables to the URL. For example, there may be two types of users involved in a chat: a user discussing a problem having a problem number (PMR) and a support representative (e.g., SME) of a company. To this extent, the PMR would be passed to the IM application as a runtime variable. This allows the support representative to look at the problem before beginning the chat with the user. In step S 7 , the generated URL is pushed to the user to redirect the IM session request  32 A to the IM server (i.e., server  24  # 3 ) at the secondary site  22 B. This is indicated by arrow  34 A in  FIG. 3 . 
     The above process is repeated for each corresponding IM session request, using the same ordered list  26  of servers  24 , to ensure that all members of the IM session are directed to the same server  24  at the same site  22 A,  22 B,  22 C in the multi-site environment  20 . For example, a corresponding IM session request  32 B received at site  22 C would result in the generation of a URL redirecting the IM session request  32 B to the first valid connection on the ordered list  26  of servers  24  (i.e., the IM server (server  24  # 3 ) at the secondary site  22 B). This is indicated by arrow  34 B in  FIG. 3 . Thus, both IM session requests  32 A,  32 B are directed to the same server  24  in the multi-site environment  20 . 
     In this implementation, the session routing portlet  28  is responsible for defining the protocol, servers, port, path, and variables and their values that are required to create a valid URL. These values are defined as initialization parameters in portlet.xml. The following code snippet is used to loop through the servers  24  in the ordered list  26  of servers  24  to determine a valid URL (NOTE: “servers” is an argument passed to the service): 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                 // Loop through all of the possible servers, looking for a URL that 
               
               
                   
                 // is valid. Use the same protocol and the same path, since the 
               
               
                   
                 // only that should be different between the sites is the server name. 
               
               
                   
                 for (int i = 0; i &lt; servers.size( ); i++) { 
               
            
           
           
               
               
            
               
                   
                 // If this seems to be a valid and working URL, build the 
               
               
                   
                 // base URL before appending the parameters to the end of it. 
               
               
                   
                 if (URLHelper 
               
               
                   
                 .isValidURL(request, protocol, (String) servers.get(i), path)) { 
               
               
                   
                 url = 
               
               
                   
                 URLHelper.buildURLWithoutParams( 
               
               
                   
                 protocol, 
               
               
                   
                 (String) servers.get(i), 
               
               
                   
                 path); 
               
               
                   
                 break; 
               
               
                   
                 } 
               
               
                   
                 } 
               
            
           
           
               
            
               
                 } 
               
               
                   
               
            
           
         
       
     
     The URLHelper.isValidURL call can be as simple or as complicated as needed. A more complicated call may include evaluation of return codes or checking for specific strings. The following code snippet is used in the URLHelper.isValidURL method called above to attempt a connection using each server  24  defined in the ordered list  26  of servers  24 : 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                 // Check to see it the connect method throws an exception 
               
               
                   
                 URL testURL = new URL(protocol, host, port, path); 
               
               
                   
                 URLConnection connection = testURL.openConnection( ); 
               
               
                   
                 connection.connect( ); 
               
               
                   
                   
               
            
           
         
       
     
     Once a valid connection is found, the variables and their corresponding values are appended to the URL string. The URLHelper class defines global variables that may be set in the initialization parameters (portlet.xml) of the session routing portlet  28 . If global variables have been configured to be included in the URL, their value will be pulled from portlet.xml and appended to the URL string. If there are additional runtime variables and values that need to be added to the URL string, a class may created to implement the RunTimeReplacement interface. This will allow a developer/administrator to define his/her own runtime variables. In an embodiment of the present invention, runtime parameters are pulled from portlet.xml in a similar manner to the global variables. 
     The solution provided by the present invention tests a URL for availability, and allows a developer/administrator to define the order in which to try connections. It also allows for flexibility by allowing the developer/administrator to define both global and runtime variables and values. 
     It should be noted that other types of front ends, other than a portal (session routing portlet  28 ), can be used to provide the session routing functionality of the present invention in response to a user request for an IM session. For example, the present invention can be implemented on a front end hosted on IIS, WAS, etc. In response to the request for an IM session, the user will be “routed” to a site using the criteria set forth herein. 
     It should also be noted that the present invention can be applied to resources other than IM. As an example, a multi-site environment may require a file storage system to store uploads to a SME. If the files which are being stored are too large to be transferred efficiently across a WAN to the different sites in real time, a user could be routed to the appropriate server to upload the requested file. 
     A computer system  100  for routing sessions to a specific URL in a multi-site environment in accordance with an embodiment of the present invention is depicted in  FIG. 4 . Computer system  100  is provided in a computer infrastructure  102 . Computer system  100  is intended to represent any type of computer system capable of carrying out the teachings of the present invention. For example, computer system  100  can be a laptop computer, a desktop computer, a workstation, a handheld device, a server, a cluster of computers, etc. In addition, as will be further described below, computer system  100  can be deployed and/or operated by a service provider that offers a service for routing sessions to a specific URL in a multi-site environment in accordance with the present invention. It should be appreciated that a user  104  can access computer system  100  directly, or can operate a computer system that communicates with computer system  100  over a network  106  (e.g., the Internet, a wide area network (WAN), a local area network (LAN), a virtual private network (VPN), etc). In the case of the latter, communications between computer system  100  and a user-operated computer system can occur via any combination of various types of communications links. For example, the communication links can comprise addressable connections that can utilize any combination of wired and/or wireless transmission methods. Where communications occur via the Internet, connectivity can be provided by conventional TCP/IP sockets-based protocol, and an Internet service provider can be used to establish connectivity to the Internet. 
     Computer system  100  is shown including a processing unit  108 , a memory  110 , a bus  112 , and input/output (I/O) interfaces  114 . Further, computer system  100  is shown in communication with external devices/resources  116  and one or more storage systems  118 . In general, processing unit  108  executes computer program code, such as session routing portlet  28 , that is stored in memory  110  and/or storage system(s)  118 . While executing computer program code, processing unit  108  can read and/or write data, to/from memory  110 , storage system(s)  118 , and/or I/O interfaces  114 . Bus  112  provides a communication link between each of the components in computer system  100 . External devices/resources  116  can comprise any devices (e.g., keyboard, pointing device, display (e.g., display  120 , printer, etc.) that enable a user to interact with computer system  100  and/or any devices (e.g., network card, modem, etc.) that enable computer system  100  to communicate with one or more other computing devices. 
     Computer infrastructure  102  is only illustrative of various types of computer infrastructures that can be used to implement the present invention. For example, in one embodiment, computer infrastructure  102  can comprise two or more computing devices (e.g., a server cluster) that communicate over a network (e.g., network  106 ) to perform the various process steps of the invention. Moreover, computer system  100  is only representative of the many types of computer systems that can be used in the practice of the present invention, each of which can include numerous combinations of hardware/software. For example, processing unit  108  can comprise a single processing unit, or can be distributed across one or more processing units in one or more locations, e.g., on a client and server. Similarly, memory  110  and/or storage system(s)  118  can comprise any combination of various types of data storage media that reside at one or more physical locations. Further, I/O interfaces  114  can comprise any system for exchanging information with one or more external devices/resources  116 . Still further, it is understood that one or more additional components (e.g., system software, communication systems, cache memory, etc.) not shown in  FIG. 4  can be included in computer system  100 . However, if computer system  100  comprises a handheld device or the like, it is understood that one or more external devices/resources  116  (e.g., a display) and/or one or more storage system(s)  118  can be contained within computer system  100 , and not externally as shown. 
     Storage system(s)  118  can be any type of system (e.g., a database) capable of providing storage for information under the present invention. To this extent, storage system(s)  118  can include one or more storage devices, such as a magnetic disk drive or an optical disk drive. In another embodiment, storage system(s)  118  can include data distributed across, for example, a local area network (LAN), wide area network (WAN) or a storage area network (SAN) (not shown). Moreover, although not shown, computer systems operated by user  104  can contain computerized components similar to those described above with regard to computer system  100 . 
     Shown in memory  110  (e.g., as a computer program product) is a session routing portlet  28  for routing sessions to a specific URL in a multi-site environment system in accordance with embodiments of the present invention. The session routing portlet  28  includes a URL helper service  30 . The URL helper service  30  includes a set of URL helper classes that are configured to generate a URL based on an ordered list  26  of servers and associated information including the protocol, port, and path. The ordered list  26  of servers can be stored in storage unit  118 . A list generation system  130  can be provided to generate the ordered list  26  of servers. Using the ordered list  26  of servers, the URL helper service  30  determines a valid URL by looping through the list until a successful connection can be found. 
     The present invention can be offered as a business method on a subscription or fee basis. For example, one or more components of the present invention can be created, maintained, supported, and/or deployed by a service provider that offers the functions described herein for customers. That is, a service provider can be used to provide a service for routing sessions to a specific URL in a multi-site environment instant messaging system, as described above. 
     It should also be understood that the present invention can be realized in hardware, software, or any combination thereof. Any kind of computer/server system(s)—or other apparatus adapted for carrying out the methods described herein—is suitable. A typical combination of hardware and software can include a general purpose computer system with a computer program that, when loaded and executed, carries out the respective methods described herein. Alternatively, a specific use computer, containing specialized hardware for carrying out one or more of the functional tasks of the invention, can be utilized. The present invention can also be embedded in a computer program product, which comprises all the respective features enabling the implementation of the methods described herein, and which—when loaded in a computer system—is able to carry out these methods. 
     The invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc. 
     The present invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer-readable medium can be any apparatus that can contain, store, communicate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. 
     The medium can be an electronic, magnetic, optical, or semiconductor system (or apparatus or device). Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, removable computer diskette, random access memory (RAM), read-only memory (ROM), rigid magnetic disk and optical disk. Current examples of optical disks include a compact disk-read only disk (CD-ROM), a compact disk-read/write disk (CD-R/W), and a digital versatile disk (DVD). 
     Computer program, software program, program, or software, in the present context mean any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: (a) conversion to another language, code or notation; and/or (b) reproduction in a different material form. 
     The foregoing description of the preferred embodiments of this invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.