Patent Publication Number: US-7594033-B2

Title: System for validating message before transforming the message into another format and switching it to selected server

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present U.S. Patent application is a divisional application of U.S. patent application Ser. No. 09/741,807 filed Dec. 22, 2000 now U.S. Pat. No. 7,111,076. 
   This application is a continuation-in-part of U.S. application Ser. No. 09/566,800 May 8, 2000 entitled “SCALABLE NETWORK APPARATUS FOR CONTENT BASED SWITCHING OR VALIDATION ACCELERATION,” which is a continuation-in-part of U.S. application Ser. No. 09/549,041 Apr. 13, 2000 entitled “A NETWORK APPARATUS FOR SWITCHING BASED ON CONTENT OF APPLICATION DATA” now U.S. Pat. No. 6,732,175 and U.S. application Ser. No. 09/562,104 May 1, 2000 entitled “A NETWORK APPARATUS FOR VALIDATING DOCUMENTS,” now U.S. Pat. No. 7,146,422 all of which are incorporated herein by reference. 

   FIELD 
   The invention generally relates to computers and computer networks and in particular to a network apparatus for transformation, such as a transforming switch. 
   BACKGROUND 
   XML, or eXtensible Markup Language v. 1.0 was adopted by the World Wide Web Consortium (W3C) on Feb. 10, 1998. XML provides a structured syntax for data exchange. XML is a markup language, like Hypertext Markup Language (HTML). Most markup languages, like HTML, are fixed markup languages. That is, the fixed markup languages, such as HTML, include a set of fixed tags for crafting a document. On the other hand, XML does not define a fixed set of tags, but rather, only defines a syntax or structured format through which users can define their own set of XML tags. There presently are a number of XML based languages which define their own set of tags using the XML syntax. XML has the further advantage because the actual data is separated from the presentation of the data, in contrast with HTML which combines these two items. As a result, XML has the potential to become a standard by which most computers, servers and applications will exchange or communicate data. 
   Due to the wide variety of data formats that are in use, including different XML languages, there is a need for a transformer to transform between the varying formats. Presently, transcoders or transformers are available to perform transformations. For example, IBM&#39;s Transcoding Technology and Microsoft&#39;s BizTalk BizMapper perform some format translation functions and typically reside on a server, such as an application server. However, the web server or the application server are typically overloaded with a variety of tasks. Taking on the extra job of transforming simply compounds this problem. Moreover, the functionality of these translators is quite limited. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and a better understanding of the present invention will become apparent from the following detailed description of exemplary embodiments and the claims when read in connection with the accompanying drawings, all forming a part of the disclosure of this invention. While the foregoing and following written and illustrated disclosure focuses on disclosing example embodiments of the invention, it should be clearly understood that the same is by way of illustration and example only and is not limited thereto. The spirit and scope of the present invention is limited only by the terms of the appended claims. 
     The following represents brief descriptions of the drawings, wherein: 
       FIG. 1  is a block diagram of a network system according to an example embodiment. 
       FIG. 2  is a flow chart illustrating an operation of content based message director according to an example embodiment. 
       FIG. 3  is a block diagram illustrating a network system including a validation accelerator according to an example embodiment. 
       FIG. 4  is a diagram illustrating an example message according to an example embodiment. 
       FIG. 5  is a flow chart illustrating an example operation of a validation accelerator according to an example embodiment. 
       FIG. 6  is a block diagram illustrating another example operating environment for a content based message director according to an example embodiment. 
       FIG. 7  is a block diagram illustrating a transforming switch according to an example embodiment. 
       FIG. 8  is a block diagram illustrating a transforming switch according to another example embodiment. 
       FIG. 9  is a flow chart illustrating an operation of a transforming switch according to an example embodiment. 
       FIG. 10  is a flow chart illustrating an operation of a transforming switch according to another example embodiment. 
   

   DETAILED DESCRIPTION 
   I. Content Based Switching 
   Referring to the Figures in which like numerals indicate like elements,  FIG. 1  is a block diagram of a network system according to an example embodiment. As shown in  FIG. 1 , a variety of clients may be coupled or connected to a data center  135  via a network, such as the Internet  130 . The clients, for example, may include a server  110  that includes an application program  112 , a computer  120  (such as a personal computer or laptop) that may include a web browser  122  and a wireless device  132 , such as a personal digital assistant (PDA) or a wireless (or cellular) telephone. Wireless device  132  may be coupled to the Internet  130  or to a data center  135  via communications links  134  and  136 , respectively. Links  134  and  136  each may include one or more of a wireless link, such as a cellular link or other link, or a wireline link. Each of the clients, including server  110 , computer  120  and device  132  can send and receive messages over the Internet  130  and may use a variety of different protocols or transports. 
   The data center  135  is provided for sending, receiving and processing a wide variety of messages, requests, business transactions, purchase orders, stock quotes or stock trades, and other information. The data center  135  includes several processing nodes, such as servers, including server  150 , server  160  and server  170  for handling the various orders, business transactions and other requests. The different servers in data center  135  may be allocated to provide different services, or even different levels of services. According to an example embodiment, the clients and the data center  135  exchange business transaction information or other information by sending and receiving XML messages, which may include data provided in XML or in a XML based language, or messages based upon another type of structured syntax for data interchange. 
   The various servers, such as servers  150 ,  160  and  170 , are coupled to a traffic manager  140  via a switch  165 . Traffic manager  140  may perform a variety of functions relating to the management of traffic, including load balancing, for example, balancing the load of incoming messages or requests across the available servers according to some policy, such as round-robin, least number of connections, or other load balancing technique. 
   Referring to the clients again in  FIG. 1 , application program  112  may be a business program or a program for managing inventory, orders or other business transactions. For example, application program  112  may automatically and electronically detect that inventory has decreased below a threshold value and then automatically generate and send a purchase order to a supplier&#39;s server at data center  135  to request a shipment of additional supplies or inventory. Thus, server  110  may initiate, for example, a business-to-business (B2B) transaction by sending an electronic order to the supplier&#39;s remote server located at data center  135 . 
   As a another example, web browser  122  may request web pages, business information or other information from a remote server, for example, located at data center  135 . Web browser  122 , may also send or post purchase orders, business transactions or other business information to a remote server, which may be located at data center  135 . Wireless device  132  may receive information or data related to purchase orders, business transactions, web pages, stock quotes, game scores and the like from one or more remote servers, such as servers located at data center  135 . 
   According to an embodiment, the server  110 , computer  120  and wireless device  132  each may communicate or interchange data with one or more remote servers, such as servers  150 ,  160  and  170 , by sending and receiving XML data, which may be application data that is encoded or formatted according to the XML standard or according to one or more XML based languages. 
   According to an example embodiment, the traffic manager  140  includes a content based message director  145  to direct or switch messages to a selected server based upon the content of application data, such as business transaction information, which may be provided as XML data as an example. Traffic manager  140  and/or message director  145  may be software, hardware or a combination of both, and may even be provided on or as part of a network processor. It should be noted that director  145  may operate by itself, or as part of a larger network apparatus, such as part of a traffic manager  140 . 
   According to an example embodiment, because of the advantages of XML, application data can advantageously exchanged between the servers of data center  135  and one or more clients or computing nodes by sending and receiving messages that include application data that is encoded or formatted according to the XML standard. Therefore, according to an embodiment, director  145  may be a XML director because it directs or switches the incoming message to a particular server based upon the XML data in the message. The XML data preferably complies with the format or syntax required by the XML standard. A document that uses tag formats, such as start tags and end tags, and other syntax or markup data that complies with the XML standard is considered to be a “well-formed” XML document. 
   Therefore, in an exemplary embodiment, content based message director  145  is a XML director. However, it should be understood that director  145  can direct or switch messages having basically any type of structured syntax, including any type of markup language. 
   An advantageous aspect of the embodiment of the traffic manager  140  and director  145  shown in  FIG. 1  is that the traffic manager  140  and the director  145  are located in front of the one or more application servers or processing nodes. By locating the traffic manager  140  and director  145  in a computer, server or computing system in front of the processing nodes or servers (as shown in  FIG. 1 ), for example, coupled between the network  130  and the servers, the traffic management functionality and the functionality of the director  145  can be off-loaded from an application server to a separate and/or dedicated network apparatus or network system. This can advantageously relieve the processing nodes or application servers from this additional processing overhead. 
   Alternatively, the director  145  may include a built-in switch with a plurality of output ports (physical ports), with a server coupled to each physical output port. In such case, a group of servers may have the same IP address or Media Access Control (MAC) address, or could have different addresses. The director  145  then would simply output or switch or forward the packet, including the message containing the XML business transaction information, via one of the physical output ports to a particular server. Regardless whether the director  145  includes a built-in switch or uses switch  165  to switch the messages to the servers, the director  145  switches or directs the messages to various servers. Switch  165  and director  145  may also switch the packet based upon other information in the packet, such as a source address or destination address. 
     FIG. 2  is a flow chart illustrating an operation of content based message director according to an example embodiment. At block  210 , the director  145  receives a message. The message may be sent over any transport or protocol(s), such as Transmission Control Protocol (TCP), File Transfer Protocol (FTP), Simple Mail Transfer Protocol (SMTP), Wireless Application Protocol (WAP, which may be used to send and receive information with wireless devices), Hypertext Transfer Protocol (HTTP), etc. The general teachings and the operation of the invention are not dependent upon any particular transport or protocol, but rather are transport-independent. 
   A HTTP Post is an example of a message. The format for an HTTP Post message (or HTTP request) may be presented as: 
   request-line (the URL); identifies a program for processing the message 
   headers (0 or more) 
   &lt;blank line&gt; 
   body (the application data or the XML data; only for a POST) 
   Here&#39;s an example: 
   
     
       
         
             
             
           
             
                 
                 
             
           
          
             
                 
               POST www;acme.com/purchasing/order.cgi HTTP/1.1 
             
             
                 
               Content-Type: text/xml 
             
             
                 
               Content-Length: 1230 
             
             
                 
               User-Agent: Cern-Line Mode/2.15 
             
             
                 
               Date: 3/27/00 
             
             
                 
               &lt;XML&gt; 
             
          
         
         
             
             
          
             
                 
               &lt;From&gt;intel.com&lt;/From&gt; 
             
             
                 
               &lt;To&gt;bookstore.com&lt;/To&gt; 
             
             
                 
               &lt;PurchaseBook&gt; 
             
          
         
         
             
             
          
             
                 
               &lt;ISBN&gt;02013798233&lt;/ISBN&gt; 
             
             
                 
               &lt;PurchaseAmount&gt; 98&lt;/PurchaseAmount&gt; 
             
          
         
         
             
             
          
             
                 
               &lt;/PurchaseBook&gt; 
             
          
         
         
             
             
          
             
                 
               &lt;/XML&gt; 
             
             
                 
                 
             
          
         
       
     
   
   In this example, the URL (or request line) is provided in a request line to identify a program or application to process the message. Several header lines (Content-type, Content-length, date, etc.) make up an HTTP header. The application data is provided after the HTTP header, and in this example is provided as XML data. A start tag &lt;XML&gt;, and &lt;/XML&gt;, an end tag, identify the start and end, respectively, of the application data (or XML data). This XML application data is also referred to as a XML document. The XML document includes markup characters (or tags) which describe data, and data characters. As an example, a “To” element of the above XML document is written as: &lt;To&gt;bookstore.com&lt;/To&gt;. Where&lt;To&gt; is a start Tag and &lt;/To&gt; is an end tag, which are markup characters because they describe the XML data characters (bookstore.com). The business transaction information describes the business transaction (To, From, items purchased, purchase amount, quantity, etc.), and is not included in the URL, the HTTP header, or any other header, such as an IP header, TCP header, of the envelope used for sending the message. These are merely examples of the types of business transaction information in a message upon which the director  145  can analyze and make routing or switching decisions for the message. 
   At block  215  of  FIG. 2 , the director  145  ( FIG. 1 ) parses all or part of the application data (the XML data in this example) and can check to ensure that the XML document or application data is well formed. For example, the director  145  may check to make sure at least a portion of the XML document meets the so-called well-formedness constraints or requirements in the XML specification or standard. Parsing generally refers to the process of categorizing the characters or XML data that make up the XML document as either markup (e.g., &lt;To&gt;) or character data (e.g., bookstore.com). 
   At block  220  of  FIG. 2 , the application data or XML data, including markup characters and/or character data, is then compared to one or more configuration patterns or queries, which may be stored in the director  145 , to determine if there is a match. According to an embodiment, the configuration patterns may be dynamically changed or updated by a user or by a program or application. For example, a program may detect the failure of one or more servers and/or detect the response time of servers, and then update the configuration pattern to account for these changes in the network, for example, to redirect certain messages from busy servers to servers which are less busy, or from servers which have failed to the available servers. 
   At block  225 , if there is a match between the content of the application data of a message, which may include the business transaction information which may be provided as XML data, and a configuration pattern or query, then the director  145  directs or switches the message to the corresponding server or processing node in the data center, for example, wherein the message is directed to the specific server as indicated by the configuration pattern. If there are multiple matches, the director  145  can just direct the message based on the first match, or a load balancing policy can be used to balance messages among a group of servers. If there is no match, the message can be directed to a default server or can be blocked. Alternatively, the configuration pattern can also identify a certain pattern for which a message should be blocked from being forwarded. In this respect, the director  145  may also act as a filter to selectively pass or forward some messages while blocking others, based upon the application data. 
   For example, the director  145  may be configured to direct or switch messages based on the following configuration patterns or queries: 
   
     
       
         
             
             
             
             
           
             
                 
             
             
               Server 
               IP address 
               Port 
               XML pattern 
             
             
                 
             
           
          
             
               S1 (e.g., 150) 
               10.1.1.1 
               80 
               To = bookstore.com 
             
             
               S2 (e.g., 160) 
               10.1.1.2 
               80 
               To = stockquote.com 
             
             
               S3 (e.g., 170) 
               10.1.1.3 
               80 
               To = computerstore.com 
             
             
                 
             
          
         
       
     
   
   Based on the above configuration patterns, the director  145  would direct a message to server S 1  (having the IP address 10.1.1.1 and port  80 ) if the data for the To element of the business transaction information is bookstore.com. The message will be directed to server S 2  (having an IP address 10.1.1.2 and port  80 ) if the data for the To element of the business transaction information is stockquote.com. And, the director  145  will direct any messages to server S 3  if the data for the To element of the business transaction information is computerstore.com. Director  145  will translate a destination address and port number of the packet to the appropriate destination address and port number (i.e., to the address of the destination server), if necessary. 
   This advantageously allows different types of services (or different levels of service) to be provided for messages based on the content of the application data, such as the business transaction information, in the message. In this example, server S 1  may be allocated to handle purchase orders for books sent to bookstore.com. Server S 2  may be allocated to process requests for real-time stock quotes, while server S 3  may be allocated to process purchase orders for computers sent to computerstore.com. 
   There are many examples where content based switching based upon the content of the application data or business transaction information can be used to offer different or differentiated services or even different or differentiated levels of services. As another example, the director  145  may be configured to direct or switch messages based on the following configuration patterns or queries: 
   
     
       
         
             
             
             
             
           
             
                 
             
             
               Server 
               IP address 
               Port 
               XML pattern 
             
             
                 
             
           
          
             
               S1 (e.g., 150) 
               10.1.1.1 
               80 
               PurchaseAmount &lt; $100 
             
             
               S2 (e.g., 160) 
               10.1.1.2 
               80 
               $100 &lt; PurchaseAmount &lt; $1000 
             
             
               S3 (e.g., 170) 
               10.1.1.3 
               80 
               $1000 &lt; PurchaseAmount 
             
             
               S4 (not shown) 
               10.1.1.4 
               80 
               $1000 &lt; PurchaseAmount 
             
             
                 
             
          
         
       
     
   
   In this example, messages for purchase orders are sent to server S 1  if the purchase amount is less than $100; messages for purchase orders are sent to S 2  if the purchase amount is less than $1000 and more than $100; and for the high dollar purchases, the messages for purchase orders for purchases greater than $1000 can be sent to either of two servers. In this fashion, the director  145  ( FIG. 1 ) can direct or route received messages based on the content of the application data or business transaction information in the message. This allows web sites or electronic-businesses (e-businesses) to offer different or differentiated levels of services based on the content of the application data or transaction information. 
   In this particular example, two servers (S 3  and S 4 ) have been allocated to handle the highest dollar purchase orders. Thus, by specifically allocating greater resources (e.g., two or more servers as compared to just one server) for the higher dollar amount purchases as compared to the lower dollar purchases, an e-business operating at data center  135  can provide a higher level of service for purchase order messages having a higher dollar purchase amount. In this manner, director  145  can switch or direct messages to another network device or to a specific server based upon a wide variety of business transaction information or application data. 
   II. Validation Acceleration 
     FIG. 3  is a block diagram illustrating a network including a validation accelerator  142  according to an example embodiment. According to an advantageous embodiment, the data center  135  also includes a validation accelerator  142  to pre-validate received messages before the messages are sent to one of the application servers or processing nodes. According to an example embodiment, the validation accelerator  142  is provided as a network apparatus. In other words, according to an example embodiment, the validation accelerator  142  can be coupled between a network  130  and a plurality of processing nodes or application servers, such as servers  150 ,  160  and  170 . Providing the validation accelerator  142  as a network apparatus that may be separate from the application servers allows the computationally expensive task of document validation to be off-loaded from the application servers to the validation accelerator  142 . Alternatively, a plurality of validation accelerators  142  may be provided, with one validation accelerator  142  being provided for one or more application servers or other processing nodes. 
   As noted above, an XML document must be checked to ensure it meets the basic syntax and format of XML, for example, to determine whether the document is “well formed”. In addition, the XML standard also optionally allows a document to be validated, which is a more rigorous check to determine if the structure or grammar of the XML document complies with structure or grammar required by the particular XML based language. XML allows a document to be validated against a validation template. A validation template defines the grammar and structure of the XML document, including required elements or tags, etc. 
   There can be many types of validation templates such as a document type definition (DTD) in XML or a schema, as examples. These two validation templates are used as examples to explain some features according to example embodiments. Many other types of validation templates are possible as well. A schema is similar to a DTD because it defines the grammar and structure which the document must conform to be valid. However, a schema can be more specific than a DTD because it also includes the ability to define data types, such as characters, numbers, integers, floating point, or custom data types, etc. In addition, unlike a DTD (under present standards), a schema may be required to be well formed. Thus, both the application data and the schema can both be parsed and checked for basic syntax or well-formedness. Therefore, at least for some applications, it is expected that schemas will possibly become more common than DTDs in the future. 
   As noted above, validating a received document against a validation template is optional according to the XML standard. If a document is to be validated against a particular validation template, the XML document will include validation instructions (or validation code) at the beginning of the document. One example of validation instructions can be a document type declaration, as commonly known in XML. Another example is a schema or a reference to an external schema. According to current XML, the validation instructions, such as document type declaration or schemas, etc. are an optional area of the document that declares the structure, element types, attributes, etc. of the validation template. To be a valid document, the structure and grammar of the application data in the document must match the structure and grammar defined by the validation template, for example, if validation instructions are included in the document. The validation template can be provided internal to (or within) the document and/or external to the document. 
     FIG. 4  is a diagram illustrating an example message according to an example embodiment. The example message shown in  FIG. 4  includes an XML document  410 . XML document  410  includes XML application data  420 , for example, including business transaction information, and validation instructions  415 . 
   The application data  420  is the application data that will be processed by an application server. The application data  420  may include, for example, business transaction information, such as a list items to be purchased, prices, quantities or other specific details of a transaction or a request for information, such as a request for stock quote, transaction details, etc. 
   According to an embodiment, the presence of one or more validation instructions  415  indicates that the document may be validated before processing the application data  420  based on a validation template provided within and/or identified by the validation instructions  415 . In other words, according to an embodiment, the presence of validation instructions may indicate that the application data should be pre-validated at a network apparatus (such as validation accelerator  142 ) before passing the data to an application server for further processing. To indicate to the application server that the document or the application data has been validated, the validation instructions may be removed from the document and/or an indication, such as a comment or instruction in the data or a field set in the message, may be provided to indicate that the application data or message has been validated (i.e., pre-validated). According to current XML, document validation is optional, for example, by the application server, even when validation instructions  415  are present. However, it is possible that in the future, validation in XML or other languages may be required. 
   If the document should be associated with a validation template, such as a document type definition, schema, etc., for document validation, the document will typically include one or more validation instructions  415 . The validation instructions  415  provide or identify the validation template or document type definition which defines the document structure and grammar, for example, elements, attributes, etc., to which the application data  420  of document  410  must conform. The validation template can include an internal component and/or an external component. 
   In this example shown, the validation instructions  415  or validation template are provided as a document type declaration. The validation instructions  415  begin with the DOCTYPE statement “&lt;DOCTYPE hogsforsale . . . ” which indicates that there is a validation template, which may be provided within the document, for example, as internal component  419 , or provided external to the document, such as an external component identified as “hogs.dtd”  417  in this example. Therefore, in this example, the validation instructions  415  provide an internal component  419  of a validation template and an external component identifier  417  identifying an external component. The internal component  419  and the external component (not shown) together form the validation template for this document for validating the application data  420  for document  410 . According to an embodiment, if validation is being performed, the presence of the DOCTYPE statement or other validation instructions typically will cause an application or application server to validate the application data  420  in the message against the validation template. 
   The internal component  419  of the validation template defines that a valid hosgsforsale document must include the following elements: type, avg wt, quantity and price/hog, etc. This is just an example. 
   In this example, the identifier “hogs.dtd” identifies an external entity or file which is an external component of the validation template. The external component can be located on a remote server or other location based on the external component identifier  417 . The external component of the validation template (identified as “hogs.dtd”) may include additional requirements on the structure or grammar of the application data  420  of the document  410 . The external component identifier  417  may be provided as the complete address, or as a relative address or pointer, for example, relative to the address or location of the source or originating node of the message. For example, the “hogs.dtd” identifier listed in the validation instructions  415  may actually reference the “hogs.dtd” external component  417  which may be found at, for example: oasis.xml.org/farming/livestock/hogs.dtd. As noted above, examples of validation templates include a Document Type Definition for XML, a schema, etc. 
     FIG. 5  is a flow chart illustrating an example operation of a validation accelerator according to an example embodiment. At block  510 , the validation accelerator  142  receives a message. The message may be sent over any transport or protocol(s), such as Transmission Control Protocol (TCP), File Transfer Protocol (FTP), Simple Mail Transfer Protocol (SMTP), Wireless Application Protocol (WAP), which may be used to send and receive information with wireless devices), Hypertext Transfer Protocol (HTTP), etc. The general teachings and the operation of the invention are not dependent upon any particular transport or protocol, but rather are transport-independent. 
   At block  515 , a validation template is obtained by the validation accelerator  142  for validating the document or message, for example, for validating the application data  420  in the document  410 ,  FIG. 4 . This may include first determining if validation instructions are present in the document or message. If no validation instructions are present, then validation will not be performed. If validation instructions are present, the validation accelerator  142  then determines whether the validation template for the document is provided as an internal component and/or an external component based upon the syntax of or one or more statements in the validation instructions  415 . 
   If the validation template is provided within the document as an internal component, the validation template is parsed from or separated from the remainder of the document. If the validation instructions  415  provide a external component identifier  417 , then the validation accelerator  142  then retrieves or obtains the external component, for example, from a remote server or node. 
   At block  520  of  FIG. 3 , the validation accelerator  142  validates at least a portion of the message, for example, validates the application data  420 , by comparing the structure and grammar of the application data  420  to the structure and grammar defined or required by the validation template. 
   At block  525 , if the document or message is valid, the validation accelerator  142  then removes the (preferably all of the) validation instructions, including any statements that might cause the document to be validated, for example, a DOCTYPE statement, any internal component(s) of the validation template and any references or identifiers to external components of the validation template. 
   At block  530 , the validated document with the validation instructions removed is then sent to an application server or other processing node for processing. 
   Alternatively (or in addition to removing the validating instructions), an indication can be added to the message indicating to the application server that the application data or message has already been validated (i.e., pre-validated). This pre-validation indication can be provided, for example, as a field in the message, as an instruction or comment in the application data itself, or using another technique. For example, In the XML specification, besides element tags, and data, there is something known as a processing instruction tag which allows information specific to an application to be embedded in an XML document. Processing instructions are not considered to be part of the character data content of an XML document, but they are always passed on to the XML application by the parser. The format is &lt;? . . . ?&gt; for the processing instruction tag. Thus, according to one embodiment, after the validation instructions (or the DTD or schema or reference thereto) has been removed, the following comment or instruction tag could be added near the beginning of the document (or other location): &lt;? validated by intel ?&gt;. 
   Alternatively, a different destination address or port number can be used in the packet header to indicate that the XML message in the packet has been pre-validated. For example, instead of port  80 , port  87  can be used as the destination port to indicate a pre-validated message for an XML document. These are just some example techniques that can be used to indicate to the server that the XML document has been already validated, or need not be re-validated. 
   By pre-validating the document and then removing the validation instructions from the document, and/or adding a pre-validation indication to the document or message, the expensive step of validation is off-loaded from the application server to a network apparatus, network appliance or other system, which may be referred to, for example, as the validation accelerator  142 . 
   III. Transformation 
     FIG. 6  is a block diagram illustrating another example operating environment for a content based message director  145  according to an example embodiment. Message director  145  and switch  165  together may be considered as a content-based switch  146 . 
   As noted above, XML does not define a fixed set of tags, but rather, only defines a syntax or structured format through which users can define their own set of tags or their own XML based language. In fact there are many different XML-based languages in use, each having a unique set of tags that define what elements should be provided to comply with that XML language. 
   An XML language can be defined by a validation template that may typically indicate the proper form for the tags, known in XML as a Document Type Definition (DTD). Schemas can also be used. For example, BizTalk by Microsoft Corp. includes one set of XML tags; CXML by Ariba Corp. includes its own set of tags; CBL by Commerce One includes another set of XML tags; While WML (Wireless Markup Language) defines yet another set of XML tags for the communication or interchange of data to and from a wireless device. Each of these XML-based languages includes a different or unique set of tags, and thus each is generally incompatible with the other languages. For example, a client sending data using CXML will not be able to properly communicate with a processing node or server that expects to receive data only provided according to CBL. 
   According to an advantageous aspect of the present invention, switch  146  can receive an XML message, compare the application data or business transaction information to the configuration pattern, and then switch the message to an appropriate processing node or server regardless of the type of XML-based language used by the message. Once the message director  145  of switch  146  is configured to detect or recognize one or more specific tags and corresponding data (for example, PurchaseAmount&gt;$100), the content based switch  146  can direct or route or switch the message based on the content of the application data, for example, based on the business transaction information provided as XML data, regardless of the type of XML-based language that is used by the message. 
   As shown in  FIG. 6 , there are three sets of servers coupled to the switch  165 , including: a set of BizTalk servers  610  (including servers  1  and  2 ) which communicate data using an XML based language known as BizTalk; a set of Ariba servers  615  (including servers  3  and  4 ) which communicate data using the XML based language known as CXML; and a set of wireless servers  620  (including servers  5  and  6 ) which communicate data using only the XML based language known as Wireless Markup Language or WML. These are merely provided as examples. 
   Messages can arrive at switch  146  in a variety of different data formats including Electronic Data Interchange (EDI), a flat alpha-numeric file format, one or more XML languages or formats (such as WML, CXML, BizTalk, eBXML, etc.), HTML, etc. Certain client computers may be able to communicate using one type of data format (or very few types of formats), while application servers (such as servers  610 ,  615 ,  620 ) each may communicate using a different type of data format. In other words, to allow clients and servers to communicate with each other where different data formats are involved, a translation or transformation function should be provided to transform from a first format to a second format. Rather than providing the transformation function as part of the application server, an embodiment of the invention provides a transformation function as part of a switch or other network apparatus (for example, a transforming switch) which may be provided, for example, between a network or Internet  130  and one or more servers or processing nodes. 
     FIG. 7  is a block diagram illustrating a transforming switch according to an example embodiment. Transforming switch  710  includes a transformer  715  to transform or translate at least a portion of a message from a first data format to a second data format or to a selected one of a plurality of second formats. Message Director  145 , which may be optional in some embodiments, is coupled to the output of transformer  715 . Message director  145  directs or switches messages to a selected server based upon the content of application data, such as business transaction information, which may be provided as XML data or data in another format. According to an example embodiment, message director  145  may output a switching decision to switch  165  based on the business transaction information of the message as compared to a pattern (or one or more patterns), as described above. Switch  165  then switches the transformed message to one of a plurality of output ports or to one of a plurality of servers (such as servers  150 ,  160  and  170 ) based on the decision or instructions from message director  145 . Because content based message director  145  may be optional in some instances, switch  165  may switch the transformed message using address-based routing or switching techniques, such as switching to a particular output port of switch  165  based on source and/or destination address and port numbers provided in the message or provided in a header of a packet carrying the message. 
   Transformer  715  can transform messages between a variety of different data formats, as required. An example communication may include a request followed by a response, although the invention is not limited in this respect. For example, a first node may issue a request over network or Internet  130  that is received by a second node. The second node may send a response back to the first node. Both the request and response may typically be routed over the Internet or network  130  and transforming switch  710 . The request and the response may both include data that may need to be transformed. The transforming switch receives the message, provided in one or more packets, determines if the data within the packet(s) needs to be transformed, performs any transformation that is required, and then forward the message via one or more packets. 
   There are four general cases involving transformations: A transform may be performed on just data in the request, on just data in the response, on data in the request and in the response, and in neither. This last case involves messages having data, if any, that is already in a format that is compatible with the receiving node, and thus, no transformation is necessary. 
   For example, web browser  122  of computer  120  may issue a request for a stock quote using a HTTP “Get” message, and be able to process data only in format A. The request may be sent via network  130  and switch  710  to server  150  without transformation, for example, because both server  150  and browser  122  are compatible with HTTP messages. Server  150  then issues the response having data (the stock quote) in format D. The data in format D may be placed in another HTTP message. While both browser  122  and server  150  are HTTP compatible, server  150  processes data in format D while browser  122  processes data in format A. Thus, transformer  715  within switch  710  would then transform the data in the response from format D to data format A and then forwards the response back to the web browser  122  over network  130 . 
   In another example, in a business-to-business (B2B) transaction, server  150  obtains a blank invoice from server  110  via Internet or network  130  and switch  710 . A software program on server  150  fills out or completes the received invoice and returns the completed invoice. The switch  710  receives the completed invoice from server  110  in format A in one or more packets, transforms the invoice from format A to format D, and then outputs the completed invoice to server  150  in format D, for example via one or more packets sent over Internet or network  130 . 
   According to an example embodiment, switch  710  may establish a connection with a first node and then receive a message, including application data, etc. from the first node via one or more packets over the first connection. Switch  710  then performs any required transformation on the message, if any, and then establishes a second connection between the switch  710  and a second node. The transformed message is then switched or output as one or more packets over the second connection to the second node. Thus, the transforming switch  710  may operate as a network apparatus to receive or intercept messages, perform any format transformation on a portion of the message if required, and then switch or forward the message via one or more packets to a destination processing node. In many cases, the presence of the transforming switch and the fact that the data or message may be transformed in one or both directions may be transparent to one or both processing nodes. 
     FIG. 8  is a block diagram illustrating a transforming switch according to another example embodiment. Transforming switch  710 A is similar to the transforming switch  710  shown in  FIG. 7 , as it includes a transformer  715 , a message director  145  and a switch  165 . The transforming switch  710 A may further include two additional elements, including a security accelerator  815  and/or a validation accelerator  142 . 
   As described above, the validation accelerator  142  validates at least a portion of the message (e.g., validates the application data  420 ,  FIG. 4 ) by comparing the structure and grammar of the application data  420  to the structure and grammar defined or required by the validation template. If the document or message is valid, the validation accelerator  142  then optionally removes the validation instructions, including any statements that might cause the document to be validated (e.g., a DOCTYPE statement), any internal component(s) of the validation template and any references or identifiers to external components of the validation template. In addition, validation accelerator  142  may add to the message an indication indicating that the application data or message has already been validated (i.e., pre-validated). In the event that the validation instructions (e.g., validation template or a reference to an external validation template) are removed from the document, the validation accelerator  142  should pass the validation instructions (such as the reference to the validation template) to the transformer  715  (e.g., to be used to identify the correct transformation template). Rather than stripping out or removing the validation instructions, the validation instructions may be left in the message to be used to perform the transformation or to determine whether a transform is required and to identify the type of transform that should be performed. The switch  710  may also add to the message an indication that the message has been transformed or an indication that the message has been transformed and validated, so as to inform a processing node that receives the message that these functions, transformation and validation, have already been performed and need not be repeated. 
   Therefore, as shown in the example embodiment of  FIG. 8 , validation accelerator  142  validates the message or document before it is transformed. This ensures that the message has the correct format and grammar before transforming the message. In addition (or in the alternative), validation accelerator  142  may validate the message after it has been transformed to the new data format. (e.g., the validation accelerator  142  may receive a copy of the transformed message from message director  145 , validate it and then notify the director  145  of its validity before the director  145  outputs the message to switch  165  for switching). The post-transformation message validation ensures that no errors occurred during the transformation. The second validation is not necessary. Validation can be performed before transformation, after transformation, both before and after transformation, or not at all. 
   Security accelerator  815  encrypts outgoing messages and/or decrypts incoming messages received from the network  130 . According to an embodiment, the security accelerator  815  may be a Secure Sockets Layer (SSL) accelerator. The security accelerator  815  allows the security related tasks such as encryption and/or decryption to be off-loaded from the application server to the accelerator  815 . Security accelerator  815  is optional. 
   The transforming switch  710  or  710 A may comprise one or more boxes, where a box could be a computer system, a network apparatus, a network appliance, a computer chassis where cards or blades can be plugged in, etc. For example, each of the functional elements of transforming switch  710 A (security accelerator  815 , validation accelerator  142 , transformer  715 , message director  145  and switch  165 ) may each be provided in a separate computer or box (with its own processor or processors, memory, etc.). Several of the functional elements of transforming switch  710 A can be combined into one or more computer systems or boxes, for example, sharing one or more processors, memory, bus, etc. All of the functional elements of transforming switch  710 A may be provided within a single box, computer, or network apparatus such as a single box or chassis with each functional element provided as a separate software program. Alternatively, transforming switch  710  or  710 A can be provided on a computer chassis, with one or more of the functional elements being provided as separate cards or blades that plug into the chassis. These are just a few examples, and the invention is not limited to these examples. 
     FIG. 9  is a flow chart illustrating an operation of a transforming switch according to an example embodiment. The flow chart of  FIG. 9  may be for an inbound message (a message from a client to a server) or for an outbound message (a message from a server to a client). The received message may first be decrypted by security accelerator  815 , and then validated by validation accelerator  142  ( FIG. 8 ). 
   Referring to  FIG. 9 , at block  910 , the transformer  715  determines if the message requires a data transformation or not. If a transformation is required, the transforming switch  710  must determine which transform to perform on the data or message. If no transform is required, for example, if the message is already in a format that may be processed by the destination application or node, then the message is simply passed on to the message director  145  and switch  165 , where the message is switched to one of a plurality of servers (or output ports) based on the business transaction information, an address, or other information, block  925 . 
   If a transformation is required, a transformation template is retrieved, block  915 . The transformation template provides instructions or code indicating how the transform should be performed. The transformation template is preferably retrieved from local storage, such as local memory or cache or local disk, if available locally, or from a remote location, for example, from another server via a network, if not locally available. The transformed message is then switched or output to a server or processing node. 
   Various embodiments of blocks  910  and  920  of the flow chart of  FIG. 9  will now be described in greater detail. 
   For block  910  ( FIG. 9 ), different types of fields or data in the received message can be examined in order to determine a type of transformation that is required (or which should be performed), if any. The transforming switch  710  may identify a transform to be performed on the basis of one or more of the following, for example: 
   a) Source address and port number of received message 
   b) Destination address and port number of received message 
   c) a program identifier—that identifies a program to process the message; for example, a request-line (the URL), such as a request line of a HTTP POST message, such as “POST www;acme.com/purchasing/order.cgi HTTP/1.1”. This program identifier may correspond to a specific format. For example, maybe this particular program can process messages provided only in format A. Thus, this program identifier in the message may be used to identify the transformation that should be performed on the received message. For instance, in this example, if the received message was provided in format B, a transformation from format B to format A may be required. 
   d) a portion of validation instructions provided within the message: The validation instructions, such as a document type declaration, schema, etc., is an optional area of the document that declares the structure, element types, attributes, etc. of the validation template. To be a valid document, the structure and grammar of the application data in the document typically should match the structure and grammar defined by the validation template, for example, if validation instructions are included in the document. The validation template can be provided internal to (or within) the document and/or external to the document. Thus, examples of validation instructions that can be used to identify a transform for the message include:
         1) a document format identifier or a reference to an external validation template, for example, a reference or URL to a DTD or schema for the message. An example would be the DOCTYPE statement “&lt;DOCTYPE hogsforsale ‘hogs.dtd”&gt;, which identifies the type of document (hogsforsale) and identifies a validation template (e.g., DTD or schema) “hogs.dtd”, that can be used to validate the document or message. Thus, if a transform is required, the transform would transform the message from the hogs.dtd format (or the hogsforsale format) to another format.   2) an internal validation template, such as a DTD or schema, such as the internal validation template  419  shown in  FIG. 4 .       

   e) one or more XML tags and/or the application data or business transaction information within the message or XML document which matches a predetermine pattern or value. A start tag &lt;XML&gt;, and &lt;/XML&gt;, an end tag, identify the start and end, respectively, of the application data (or XML data). This indicates that the message is provided in XML format. The XML document or message includes markup characters (or tags) which describe data, and data characters. As an example, a “To” element of an XML document is written as: &lt;To&gt;bookstore.com&lt;/To&gt;. Where&lt;To&gt; is a start Tag and &lt;/To&gt; is an end tag, which are markup characters because they describe the XML data characters (bookstore.com). For example, maybe all transaction data to and from “Bookstore.com” are provided in format A, while all transaction data or message to and from “market.com” are provided in format B. Thus, tags or specific business transaction information can be used to identify that a corresponding transform should be used to transform certain messages. In this example, the “to: Bookstore.com” and “from: market.com” tags and data can be used to determine that “format B to format A” transformation template should be used to transform the message or data. 
   Or, if all servers or applications behind a switch  710  with a specific address/and/or port number are known by switch  710  to communicate messages only using format C. The switch  710  may then examine other information in the message or packet to determine the correct format transformation (including a transformation either to or from format C). 
   According to an example embodiment, a first pattern in a received message can be used to identify a transform to be performed on the message, while a second pattern in the message can be used to switch the message to a specific server (content based switching). For example, if a received XML message includes a tag that says “&lt;AXML&gt;,” then this may indicate that the data is provided in AXML format. Let&#39;s also assume that Bookstore.com can process messages or transactions provided only in BXML format. Thus, if the “To” tag in the document says “To: Bookstore.com” (or if the destination address corresponds to Bookstore.com), then the transformer  715  will transform the message from AXML to BXML using an appropriate transformation template, such as an “AXML to BXML” transformation template. The reverse transformation would be used to transform any reply messages from Bookstore.com. 
   f) a field, such as a “User Agent” field in a HTTP message, that identifies the type of application or device that sent a message, such as a wireless device that can process messages in data format A, or a web browser that can process messages in data format B. These are just a couple of examples. 
   At block  920  ( FIG. 9 ), transformer  715  ( FIGS. 7-8 ) transforms at least a portion of a received message from a first data format to a second data format. There are many different ways in which this can be performed. According to one example, a transformation template is used that describes how the tags and data are transformed from one format to another format. An example of a transformation template is an XML Style Language Transform (XSLT). Here is one example that illustrates how a XSLT (or transformation template) can be used to perform a transformation. 
   The received message is provided in a TypeAxml format and needs to be transformed to a TypeBxml format. The start tag “&lt;TypeAxml&gt; indicates that this message is provided in TypeAxml format. Here is the received message: 
                              &lt;? xml version=″1.0″?&gt;       &lt;TypeAxml&gt;                         &lt;PurchaseOrder&gt;           &lt;From&gt;acme.com&lt;/From&gt;           &lt;To&gt;widgetmaker&lt;/To&gt;           &lt;Part&gt;                         &lt;Partnumber&gt;100-32323&lt;/Partnumber&gt;           &lt;Description&gt;Widget&lt;/Description&gt;           &lt;Qty&gt;3&lt;/Qty&gt;                         &lt;/Part&gt;           &lt;/PurchaseOrder&gt;                 &lt;/TypeAxml&gt;       Here is the XSLT stylesheet to transfrom a PurchaseOrder from TypeAxml       into TypeBxml:       &lt;xsl:stylesheet version=″1.0″       xmlns:xsl=″http://www.w3.org/1999/XSL/Transform″&gt;       &lt;xsl:template match=″/″&gt;       &lt;? xml version=″1.0″?&gt;       &lt;TypeBxml&gt;                         &lt;PurchaseOrder&gt;           &lt;Sender&gt;&lt;xsl:value-of select=″//From″/&gt;&lt;/Sender&gt;           &lt;Receiver&gt;&lt;xsl:value-of select=″//To″/&gt;&lt;/Receiver&gt;           &lt;PartItem&gt;                         &lt;Number&gt;&lt;xsl:value-of select=″//Part/Partnumber″/&gt;&lt;/Number&gt;           &lt;Description&gt;&lt;xsl:value-of                 select=″//Part/Description″/&gt;&lt;/Description&gt;                         &lt;Qty&gt;3&lt;/Qty&gt;                         &lt;/PartItem&gt;           &lt;/PurchaseOrder&gt;                 &lt;/TypeBxml&gt;       &lt;/xsl:template&gt;       &lt;/xsl:stylesheet&gt;                    
The transformed output message looks like this:
 
   
     
       
         
             
             
           
             
                 
                 
             
           
          
             
                 
               &lt;? xml version=″1.0″?&gt; 
             
             
                 
               &lt;TypeBxml&gt; 
             
          
         
         
             
             
          
             
                 
               &lt;PurchaseOrder&gt; 
             
             
                 
               &lt;Sender&gt;acme.com&lt;/Sender&gt; 
             
             
                 
               &lt;Receiver&gt;widgetmaker&lt;/Receiver&gt; 
             
             
                 
               &lt;PartItem&gt; 
             
          
         
         
             
             
          
             
                 
               &lt;Number&gt;100-32323&lt;/Number&gt; 
             
             
                 
               &lt;Description&gt;Widget&lt;/Description&gt; 
             
             
                 
               &lt;Qty&gt;3&lt;/Qty&gt; 
             
          
         
         
             
             
          
             
                 
               &lt;/PartItem&gt; 
             
             
                 
               &lt;/PurchaseOrder&gt; 
             
          
         
         
             
             
          
             
                 
               &lt;/TypeBxml&gt; 
             
             
                 
                 
             
          
         
       
     
   
   In this example some of the element names from TypeAxml need to be transformed or converted to the element names that are compatible with TypeBxml. 
   From TypeAxml, element &lt;From&gt; needs to be converted to TypeBxml element &lt;Sender&gt; 
   From TypeAxml, element &lt;To&gt; needs to be converted to TypeBxml element &lt;Receiver&gt; 
   From TypeAxml, element &lt;Part&gt; needs to be converted to TypeBxml element &lt;PartItem&gt; 
   From TypeAxml, element &lt;Partnumber&gt; needs to be converted to TypeBxml element &lt;Number&gt; 
   In this example none of the data or values corresponding to the transformed elements are changed, just the element names (or tags) are changed. Also, note that the first start tag &lt;TypeAxml&gt; needs to be converted to &lt;TypeBxml&gt;. Similarly, the end tag &lt;/TypeAxml&gt; needs to be converted to &lt;/TypeBxml&gt;. This change will indicate to the application server that the message is in the proper format for processing. 
     FIG. 10  is a flow chart illustrating an operation of a transforming switch according to another example embodiment, such as an inbound request to a server, and the outbound response from the server back to a client. 
   In this example of  FIG. 10 , a request for information may be submitted by a client to a server, for example, via transforming switch  710 . For example, this request may be a request for a stock quote from a web browser. The request is received by the application server, the data is obtained from a database coupled to the application server. The application server then creates an XML response message providing the requested stock quote (for example). At block  1005 , this response message (e.g., an XML message) is received at transforming switch  710 . 
   At block  1010 , the transforming switch determines the type of transform that is required, if any. If no transform is required, the message is then switched or output, block  1070 . In this example, because the initial request arrived at the transforming switch  710  from an HTML application (e.g., based on a header of the stock quote request indicating HTML, or the User Agent indicating an HTML application submitted the original request, etc.), the transforming switch  710  determines that a XML to HTML transform is required. 
   At block  1025 , a determination is made as to whether the (client-specific) transformation template is available to perform the corresponding transformation. If the requested (or client-specific) transformation template is not available, then a default transformation template is retrieved either from a local store  1055  or from a remote location  1060 . This default transformation is then used to transform the response message, block  1020 . 
   If the requested (client-specific) transformation template is available, the client-specific (or requested) transformation template is retrieved from a local store if available, block  1035 , or from a remote location (e.g., retrieved from a server via a network) if not locally available, block  1040 . 
   The retrieved transformation template is then used to transform the response message, block  1020 . The transformed message is then output to the network  130  for routing back to the requesting client application, block  1070 . 
   Several embodiments of the present invention are specifically illustrated and/or described herein. However, it will be appreciated that modifications and variations of the present invention are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.