Abstract:
A system and method is provided for optimizing a SyncML slow sync between a proprietary client and server. When a slow sync is detected, the client and server can depart from the normal SyncML protocol and process summary data without having to compare all items on a field-by-field basis.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 10/745,529, filed Dec. 29, 2003. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a system and method for performing an optimized SyncML slow sync between a proprietary client and server. 
       BACKGROUND OF THE INVENTION 
       [0003]    Synchronizing client and server data is typically known in the art. SyncML is a protocol that defines a common data synchronization protocol that can be used industry-wide. Client and server devices exchange information with each other regarding changes to documents and other files stored at their respective locations. Anchors are used to inform the receiving client or server of the time the last update was received from the sending client or server. These anchors are sometimes missing or corrupt. 
         [0004]    In the SyncML and other synchronization protocols, devices being synchronized with each other for the first time, or whose anchors are missing or corrupt, require a full document-by-document, field-by-field synchronization. This field-by-field sync is known as a slow sync. The slow sync can be desired for many reasons. For example, the client or the server has lost its change log information or the sync anchors may be mismatched. 
         [0005]    Slow sync is a two-way synchronization process. During a slow sync, a client device must send all of the documents in its database to the server. The server then compares all of the documents received from the client with the documents the server has stored. After performing a sync analysis, the server returns all needed modifications to the client. Doing a field-by-field analysis during a slow sync can be very inefficient because large amounts of unnecessary data for each document may be exchanged. 
         [0006]    Other limitations and problems also exist. 
       SUMMARY OF THE INVENTION 
       [0007]    A system and method is provided for optimizing the performance of a SyncML slow sync between a proprietary client and a proprietary server. 
         [0008]    According to some embodiments of the invention, a server and client must be designated proprietary to take advantage of this slow sync optimization. In other embodiments, a proprietary client and/or server may support other non-proprietary SyncML compliant devices by performing a full slow sync. The data being synchronized must support a global unique identifier and a modified time for each document. 
         [0009]    According to some embodiments, a proprietary client may send summary data during a slow sync and a proprietary server may process summary during a slow sync. 
         [0010]    According to some embodiments of the invention, client and server messages are exchanged which include message anchors. The message anchors may indicate the date and time of the last update or modification. If the anchors are missing or corrupt, a slow sync is initiated. 
         [0011]    According to some embodiments, a slow sync may be initiated by a proprietary client. The proprietary client may initiate a slow sync at the request of a server or may initiate the slow sync upon the receipt of a synchronization message having missing or corrupt anchors. 
         [0012]    According to some embodiments, once the client and server have been identified as proprietary, a proprietary client provide the server with summary data for all of its documents. From the summary data, the server is able to determine what changes have occurred. 
         [0013]    According to further embodiments, a proprietary client may send summary data to a proprietary server as a series of ADD commands. The summary data may include modified message timestamps, enabling the proprietary server to immediately process the ADD commands. In some embodiments, the proprietary server may respond to the proprietary client by sending its changes and identifying what documents need to be sent from the client. 
         [0014]    Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings that disclose embodiments of the invention. It should be understood, however, that the drawings are designed for purposes of illustration only and not as a definition of the limits of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  illustrates a system diagram in accordance with the invention. 
           [0016]      FIG. 2  illustrates a process for synchronizing a proprietary client and server, according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]      FIG. 1  illustrates a system diagram in accordance with the invention. System  100  may include a client  110 . Client  110  may include a client agent  112 . Client agent  112  may be used to send data modifications to a server device  120 . Client agent  112  may also receive modifications from server  120 . Client  110  may communicate with a storage device, such as database  114 , or other storage mechanisms. While shown separate from client  110 , database  114  may be integrated with client  110  or may be a part of another device, as would be apparent. Client  110  may include, for instance, a personal computer, a portable laptop computer, a handheld computer device such as a Blackberry, Palm Pilot, or other PDA, or any other client device. 
         [0018]    Client  110  may communicate with a server  120  over network  130  via communication link  132 . Network  130  may comprise include, for example, the Internet, an intranet, a LAN (Local Area Network), a WAN (Wide Area Network), or other communications networks. Communication link  132  may include, for example, a copper telephone line, a Digital Subscriber Line (DSL) connection, an Ethernet connection, an Integrated Services Digital Network (ISDN) line, a wireless connection, or other communications link. 
         [0019]    Server  120  may include a sync engine  122  and a server agent  124 . Server  120  may communicate with a storage device, such as server database  126 , or other storage mechanism. While shown separate from server  120 , database  126  may be integrated with server device  120 , or may be a part of another device, as would be apparent. Server  120  may be or include, for example, a personal computer, a workstation, or other suitable server device running Microsoft Windows™ NT™, Microsoft Windows™ 2000, Unix, Linux, Novell Netware™, Sun Microsystems Solaris™, OS/2™, Apache, or other operating system. 
         [0020]    Server agent  124  may be used to send data modifications to client  110 . Server agent  124  may also receive data modification from client  110 . Sync engine  122  may be used for performing a sync analysis between client documents and server documents. Sync engine  122  may also be used for solving conflicts between client and server documents. 
         [0021]    Database  114  and database  126  may store documents at the client and server, respectively. A user accessing these documents at either location may make modifications. In order to maintain consistent data at both locations, synchronization may be used. SyncML defines a uniform protocol for synchronizing devices of various types. SyncML packages are transmitted back and forth between a client and server after document changes are made, with the transfer beginning at a client. Before a client and server device can synchronize documents, initialization is required. Initialization may be initiated by a client device or by a server device. Synchronization anchors may be used to indicate the range of data that needs to be synchronized. Synchronization anchors provide the date and time of the last synchronization for a particular database, and the date and time for initializing a new sync process. A client and server device store the anchors for one another. If the anchors are missing or corrupt, a slow sync must be initiated. 
         [0022]    According to one aspect of the invention, a proprietary client and server may depart from the SyncML specification during the slow sync process when missing or corrupt anchors are received. A proprietary client may send only summary data for all of its records rather than the entire document, as is done in a normal SyncML slow sync. A client may be designated proprietary by placing a notation in the Meta element of the SyncML header. A server may be designated proprietary looking for this notation in the client&#39;s SyncML header and responding by placing a notation in the Meta element of its own SyncML header. 
         [0023]      FIG. 2  illustrates a process for synchronizing a proprietary client and server according to one embodiment of the invention. At an operation  200 , server  120  may receive a synchronization package having corrupt or missing synchronization anchors. Server  120  may request a slow sync, at an operation  202 . To request the slow sync, server  120  may send a slow sync initialization package to client  110 . The slow sync initialization package may include a command requesting client  110  to send all of the documents from its database, synchronization anchors for the last synchronization packages received from client  110 , and other initialization information. 
         [0024]    At an operation  204 , client  110  may receive the slow sync initialization package and determine if the request was sent by a proprietary server. Proprietary client may determine if the request was initiated by a proprietary server by examining header information. If the request was initiated by a proprietary server, proprietary client  110  may depart from the SyncML protocol by sending a sync package containing only summary data related to all documents in its database to proprietary server  120 , at an operation  206 . If the request was not initiated by a proprietary server, client  110  may continue with the SyncML slow sync process by sending the contents of its entire database to server  120 , at an operation  208 . Summary data may be sent as a series of ADD commands having only the minimum data required to determine if the document should be included in the sync. Summary data may include document identification information, the type of action to be performed, the mime type of the data, and a message timestamp indicating the time the package is being sent. 
         [0025]    At an operation  210 , proprietary server  120  may receive the sync package from proprietary client  110  and detect whether the package was sent by a proprietary client. Normally, a client would have to respond to a server initiated slow sync request by sending all documents from its database back to the server if the anchors do not match. However, according to an embodiment of the invention, a proprietary server  120  may process the received summary data. Proprietary server  120  determines whether the sync package was sent from a proprietary client by examining header information. If proprietary server  120  does not detect a proprietary client, an error message may be sent, at an operation  211  or server may proceed according to a standard SyncML protocol. 
         [0026]    Once proprietary server  120  has detected a proprietary client, proprietary server  120  may immediately process the ADD commands, at an operation  212 . The server may process ADD commands by comparing a global unique identifier and a modified time for each document from the client to its locally stored global unique identifier and modified time. If the global unique identifier and a modified time match on both the client document and server document then the documents are considered the same and no further processing is required for this document. 
         [0027]    If the global unique identifier of a client document does not exist on the server then the document is considered an addition to the server and this status is noted and sent back to client. When the client receives and processes this status, it may modify its timestamp to a value higher than the next anchor so that this missing document will be included in any subsequent sync processes. These changes may be reflected on the server on the next fast sync. If the global unique identifier of a server document does not exist on the client then the document is considered an ADD to the client and document is sent to client in response to this message. 
         [0028]    Proprietary server  120  may send to proprietary client  110  the results of the sync after the ADD commands have been performed. Proprietary server  120  may send a status indicating whether the document is one that proprietary server  120  already has in its database or whether the database does not already contain the document. At an operation  214 , the synchronization process continues when proprietary client  110  receives the modifications and results form proprietary server  120 . At an operation  216 , in a subsequent sync session, proprietary client  110  may respond by sending proprietary server  120  instructions to replace those records that it does not already contain, as indicated in the previous session. At an operation  218 , proprietary server  120  will process the replace instructions and reply to proprietary client  110  with the status. It is important to notice here that operations  216  and  218  are part of a subsequent sync; this allows proprietary client and server to comply with SyncML protocol during slow sync. 
         [0029]    While the above describes proprietary server  120  as being the initiator of the slow sync, proprietary client  110  may also initiate a slow sync. If proprietary client  110  receives a sync package having missing or corrupt anchors, proprietary client may initiate a slow sync by issuing an alert command to proprietary server  120  that a slow sync is being started. After acknowledgement from proprietary server  120 , operation continues as described above at an operation  220  with proprietary client  110  sending summary data if the server is proprietary. 
         [0030]    While particular embodiments of the present invention have been described, it is to be understood that modifications will be apparent to those skilled in the art without departing from the spirit of the invention.