Abstract:
A cloud data storage system includes a plurality of storing units, a plurality of processing units, and a plurality of user ends. The processing units are connected to the storing units via the Internet, and the user ends are connected to one of the processing units. An upload file to be stored by a user end is divided into a plurality of file blocks, and an algorithm is used to compute eigenvalues corresponding to the file blocks respectively. The eigenvalues is computed by applying another algorithm in order to decide which storing units the file blocks can be stored in. Each of the eigenvalues corresponds to a different storing unit. For a data uploading and downloading process, the eigenvalues are used to decide the final storage locations and the information associated with combining the transferred file.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefits of the Taiwan Patent Application Serial Number 099116333, filed on May 21, 2010, the subject matter of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a data storage system and, more particularly, to a cloud data storage system suitable for cloud computing. 
         [0004]    2. Description of Related Art 
         [0005]    Cloud computing is an Internet-based computing approach to provide real-time services to users via the Internet. In the near future, all users can execute programs and software and store the file data in the Internet. Thus, the transmission efficiency of the file data, the recognition and storage of repeated data, the identification and elimination of viruses, and the privacy and protection of data will be important issues of the cloud computing. 
         [0006]    Interactions via the Internet are getting more and more with the increasing of online populations, same data and same operations (including viruses) replicated and flowed in the Internet will slow down the speed and capabilities to cause severe damages to the Internet. 
         [0007]    For example, popular video data via transfer tools such as email, network drive, and the like can be replicated to hundreds or thousands of copies, and hundred millions times data transfer. In addition, certain popular keywords might be searched or used by hundreds or thousands of people. If such repeated actions occurred continuously, Internet resources will be wasted and the whole network can be crashed easily. 
         [0008]    Therefore, it is desirable to provide an improved cloud data storage system to mitigate and/or obviate the aforementioned problems. 
       SUMMARY OF THE INVENTION 
       [0009]    The object of the present invention is to provide a cloud data storage system, which can reduce the repeated data storage and the repeated transfer between networks thereby to develop the actual benefits of network. 
         [0010]    To achieve the object, the invention provides a cloud data storage system. The system includes a plurality of storing units, a plurality of processing units connected to the plurality of storing units via the Internet and a plurality of user ends connected to one of the plurality of processing units. In between, where an upload file to be stored by any user end is divided into a plurality of file blocks, the plurality of file blocks are computed by an algorithm to obtain corresponding eigenvalues. The eigenvalues are computed by another algorithm to decide which storage units the plurality of file blocks can be stored in. The plurality of eigenvalues compose a set of eigenvalues corresponds to the data file. 
         [0011]    A first upload method in the invention is to query a storing unit by a user end whether there are same eigenvalues. The file blocks having the same eigenvalues as the corresponding storing unit are not transferred. Other file blocks not having the same eigenvalues as the corresponding storing unit are transferred to the storing unit. 
         [0012]    In addition, each processing unit contains an eigenvalue table and a buffer area. The eigenvalue table is used to be compared with an upload file, and the buffer area is used to store the plurality of file blocks for data cache purpose. 
         [0013]    A second upload method in the invention includes the following steps: the user end sends the eigenvalue set to one of the plurality of processing unit, and uses the eigenvalue table of the processing unit to proceed with data comparison. If the eigenvalue table contains same eigenvalues, the user end does not send the corresponding file blocks. If the eigenvalue table did not contain same eigenvalues, the processing unit sends the eigenvalues to a corresponding storing unit for data comparison. The storing unit sends back the eigenvalues not containing same eigenvalues to the processing unit. The processing unit thus makes the user end to send the corresponding file blocks not containing same eigenvalues to the buffer area of the processing unit. The processing unit sends the files blocks not containing same eigenvalues storing in the buffer area to the corresponding storing units. 
         [0014]    A first download method in the invention includes the following steps: when one of the user ends downloads the file, according to the content of the plurality of eigenvalues set, the position of the corresponding storing unit is computed to download the corresponding file blocks. The user end combines the file blocks according to sequence of the eigenvalue set of the file. 
         [0015]    A second download method in the invention includes the following steps: when one of the user ends downloads the file, the user end sends the eigenvalue set to one of the processing units of the plurality of the processing units and proceeds with data comparison according to the eigenvalue table of the processing unit. If the eigenvalue table of the processing unit contains the same eigenvalues, the processing unit extracts the corresponding file blocks from the buffer area to send back to the user end. If the eigenvalue table of the processing unit does not contain the same eigenvalues, the processing unit computes to get the position of the corresponding processing unit according to the eigenvalue and sends the eigenvalue to the corresponding storing unit. The storing unit sends the corresponding file block to the processing unit. The processing unit receives the corresponding file block and stores in the buffer area and sends the file block to the corresponding user end. The user end combines the file blocks according to sequence of the eigenvalue set of the file. 
         [0016]    Other objects, advantages, and features of the invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a system configuration according to an embodiment of the invention; 
           [0018]      FIG. 2  is a first schematic diagram illustrating a file upload process according to an embodiment of the invention; 
           [0019]      FIG. 3  is a second schematic diagram illustrating the file upload process according to an embodiment of the invention; 
           [0020]      FIG. 4(   a ) is a third schematic diagram illustrating the file upload process according to an embodiment of the invention; 
           [0021]      FIG. 4(   b ) is a schematic diagram of an eigenvalue table of a processing unit according to an embodiment of the invention; 
           [0022]      FIG. 5  is a fourth schematic diagram illustrating the file upload process according to an embodiment of the invention; 
           [0023]      FIG. 6  is a first schematic diagram illustrating a file download process of a file according to an embodiment of the invention; and 
           [0024]      FIG. 7  is a second schematic diagram illustrating the file download process according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]      FIG. 1  is a configuration of a cloud data storage system according to an embodiment of the invention. As shown in  FIG. 1 , the system includes a plurality of user ends, a plurality of processing units, and a plurality of storing units. For convenience of description, in this embodiment, the system includes eight user ends A 1 -A 8 , three processing units B 1 -B 3 , and ten storing units IP 1 -IP 10 . The user ends A 1 -A 8  are connected to at least one of the processing units B 1 -B 3  via the Internet or a local area network (LAN), and the storing units IP 1 -IP 10  are connected to the processing units B 1 -B 3  via the Internet or the LAN. Each of the processing units B 1 -B 3  includes a buffer area (not shown) to store the block data for cache purpose. Each of the user ends A 1 -A 8  and the storing units IP 1 -IP 10  includes a hard drive (not shown) to store the permanent data. 
         [0026]      FIG. 2  is a first schematic diagram illustrating a file upload process according to an embodiment of the invention. As shown in  FIG. 2 , a user uses the user end A 1  to upload a file X. The file X is first divided into eight blocks, Block 0 -Block 7 , for example. The file data of the eight blocks is applied to a hash algorithm, such as an MD5 algorithm, to compute the eigenvalues respectively. In this embodiment, after the computation, an eigenvalue of 135496 is obtained for Block 0 , 23187 for Block 1 , 245681 for Block 2 , 3347654 for Block 3 , 86721 for Block 4 , 3341 for Block 5 , 1357892 for Block 6 , 123456 for Block 7 . The eigenvalues form an eigenvalue set recorded in the internal eigenvalue table Y of the user end A 1 , and the user end A 1  transfers the eigenvalue set to the processing unit B 1 . 
         [0027]    Next,  FIG. 3  is a second schematic diagram illustrating the file upload process according to an embodiment of the invention. As shown in  FIG. 3 , when received the eigenvalue set, the processing unit B 1  compares the eigenvalue set with the internal eigenvalue table W and deletes the same eigenvalues (in this case, 86721 and 1357892). The remaining eigenvalues (135496, 23187, 2245681, 3347654, 3341, 123456) are applied to another hash algorithm to obtain a set of digits corresponding to a storing unit. For example, the hash algorithm applied here makes the eigenvalues 135496, 23187, 2245681, 3347654, 3341, 123456 to be divided respectively by a fixed value (here 10 as divisor for example), and takes the remainders to form a number sequence [6, 7, 1, 4, 1, 6] corresponding to the storing units IP 6 , IP 7 , IP 1 , IP 4 , IP 1 , IP 6  respectively. In between, the storing unit IP 1  corresponds to the eigenvalues 2245681 and 3341, the storing unit IP 4  corresponds to the eigenvalue 3347654, the storing unit IP 6  corresponds to the eigenvalues 135496 and 123456, and the storing unit IP 7  corresponds to the eigenvalue 23187. 
         [0028]    According to the corresponding relation, the processing unit B 1  transfers the eigenvalues 2245681, 3341 to the storing unit IP 1 , transfers the eigenvalue 3347654 to the storing unit IP 4 , transfers the eigenvalues 135496, 123456 to the storing unit IP 6 , and transfers the eigenvalue 23187 to the storing unit IP 7 . 
         [0029]    Next,  FIG. 4(   a ) is a third schematic diagram illustrating the file upload process according to an embodiment of the invention. As shown in  FIG. 4(   a ), after received the eigenvalues 2245681, 3341 from the processing unit B 1 , the storing unit IP 1  compares the eigenvalues 2245681, 3341 with its own eigenvalue table IP 1 ′ and finds to contain the eigenvalue 2245681 and not to contain the eigenvalue 3341. Therefore, the storing unit IP 1  sends the eigenvalue 3341 back to the processing unit B 1 . 
         [0030]    After received the eigenvalue 3347654 from the processing unit B 1 , the storing unit IP 4  compares the eigenvalue 3347654 with its own eigenvalue table IP 4 ′ and finds not to contain the eigenvalue 3347654. Therefore, the storing unit IP 4  sends 3347654 back to the processing unit B 1 . 
         [0031]    After received the eigenvalues 135496, 123456 from the processing unit B 1 , the storing unit IP 6  compares the eigenvalues 135496, 123456 with its own eigenvalue table IP 6 ′ and finds not to contain the eigenvalues 135496, 123456. Therefore, the storing unit IP 6  sends 135496, 123456 back to the processing unit B 1 . 
         [0032]    After received the eigenvalue 23187 from the processing unit B 1 , the storing unit IP 7  compares the eigenvalue 23187 with its own eigenvalue table IP 7 ′ and finds not to contain the eigenvalue 23187. Therefore, the storing unit IP 7  sends 23187 back to the processing unit B 1   
         [0033]    After received the eigenvalues 3341, 3347654, 135496, 123456, 23187 from storing units IP 1 , IP 4 , IP 6 , IP 7 , the processing unit B 1  sends those eigenvalues to the user end A 1 . 
         [0034]    After received the eigenvalues 3341, 3347654, 135496, 123456, 23187 returned from the processing unit B 1 , the user end A 1  transfers the corresponding file blocks Block 5 , Block 3 , Block 0 , Block 7 , Block 1  to the processing unit B 1 . After received the file blocks Block 5 , Block 3 , Block 0 , Block 7 , Block 1  transferred by the user end A 1 , the processing unit B 1  stores the received file blocks in the buffer area and adds the eigenvalues 3341, 3347654, 135496, 123456, 23187 to the eigenvalue table W, as shown in  FIG. 4(   b ). 
         [0035]    Next, the processing unit B 1  transfers the eigenvalue 3341 and the file block Block 5  to the storing unit IP 1 , transfers the eigenvalue 3347654 and the file block Block 3  to the storing unit IP 4 , transfers the eigenvalue 135496 and the file block Block 0 , the eigenvalue 123456 and the file block Block 7  to the storing unit IP 6 , and transfers the eigenvalue 23187 and the file block Block 1  to the storing unit IP 7 . 
         [0036]      FIG. 5  is a fourth schematic diagram illustrating the file upload process according to an embodiment of the invention. As shown in  FIG. 5 , after received the eigenvalue 3341 and the file block Block 5  transferred by the processing unit B 1 , the storing unit IP 1  stores the file block Block 5  in the internal hard drive and adds the eigenvalue 3341 to the internal eigenvalue table IP 1 ′. After received the eigenvalue 3347654 and the file block Block 3  transferred by the processing unit B 1 , the storing unit IP 4  stores the file block Block 3  in the internal hard drive and adds the eigenvalue 3347654 to the internal eigenvalue table IP 4 ′. After received the eigenvalue 135496, the file block Block 0  and the eigenvalue 123456, the file block Block 7  transferred by the processing unit B 1 , the storing unit IP 6  stores the file blocks Block 0 , Block 7  in the internal hard drive and adds the eigenvalues 135496, 123456 to the internal eigenvalue table IP 6 ′. After received the eigenvalue 23187 and the file block Block 1  transferred by the processing unit B 1 , the storing unit IP 7  stores the file block Blockl in the internal hard drive and adds the eigenvalue 23187 to the internal eigenvalue table IP 7 ′. 
         [0037]    After the user end A 1  completes the upload process, the eigenvalue set (135496, 23187, 2245681, 3347654, 86721, 3341, 1357892, 123456) corresponding to the file blocks Block 0 -Block 7  is stored in the hard drive of the user end A 1  to thereby complete the data writing process and keep the eigenvalue set as a key of reading the file X in next time. The key is held and replicated by a user, so that the processing units and the storing units cannot reproduce the file X since they do not keep the eigenvalue set. Therefore, the user&#39;s data is absolutely safe without possibility of leakage. 
         [0038]    In addition, when the user end A 1  sends the eigenvalue set to the processing unit B 1  and finds that the buffer area of the processing unit B 1  already contained the corresponding eigenvalue set of the file X, the processing unit B 1  will not proceed with the query action to IP 1 -IP 10  and reply directly to the user end A 1  with containing the corresponding file block data. 
         [0039]    The invention also provides two cloud data download processes as follows. 
         [0040]      FIG. 6  is a first schematic diagram illustrating a file download process according to an embodiment of the invention. As shown in  FIG. 6 , the processing unit B 1  has an eigenvalue table W 1  with the eigenvalues of the user end A 1 . 
         [0041]    First, the user end A 1  extracts the eigenvalue set Y of the file X from the internal hard drive and transfers the eigenvalue set (135496, 23187, 2245681, 3347654, 86721, 3341, 1357892, 123456) to the processing unit B 1 . After received the eigenvalue set, the processing unit B 1  compares with the eigenvalue table W 1 . From  FIG. 6 , it is known that all eigenvalues are successfully compared as matched, so the processing unit B 1  reads the file blocks Block 0 -Block 7  corresponding to the eigenvalues from the internal buffer area and returns the file blocks to the user end A 1 . After received the file blocks Block 0 -Block 7  transferred by the processing unit B 1 , the user end A 1  recombines the file blocks Block 0 -Block 7  into the complete file X based on the sequence of the eigenvalue set to thereby complete the data download process. In this case, the data fully comes from the processing unit B 1 , and thus there is no need to read from far-end storing units, so as to increase the efficiency of Internet or Web utility and reduce the waste of resource. 
         [0042]      FIG. 7  is a second schematic diagram illustrating the file download process of  FIG. 7  according to an embodiment of the invention. As shown in  FIG. 7 , the eigenvalue table W 2  of the processing unit B 2  does not contain all eigenvalues of the eigenvalue table Y of the user end A 1 . 
         [0043]    First, the user end A 1  extracts the eigenvalue set Y of the file X from the internal hard drive and transfers the eigenvalue set (135496, 23187, 2245681, 3347654, 86721, 3341, 1357892, 123456) to the processing unit B 2 . After received the eigenvalue set, the processing unit B 2  compares the eigenvalue set Y with the eigenvalue table W 2 . It is seen in  FIG. 7  that only part of the eigenvalues is successfully compared as matched. In this case, the processing unit B 2  reads the file blocks (Block 6 , Block 5 , Block 0 , Block 1 ) corresponding to the successfully matched eigenvalues (1357892, 3341, 135496, 23187) from the internal buffer area and sends them back to the user end A 1 . According to the hash algorithm used in the upload process, the mismatched eigenvalues (2245681, 3347654, 86721, 123456) are divided by a fixed value 10 so as to obtain a number sequence [1, 4, 1, 6] and find the storing units IP 1 , IP 4 , IP 1 , IP 6  corresponding to the number sequence. In between, the storing unit IP 1  corresponds to the eigenvalues 2245681, 86721, the storing unit IP 4  corresponds to the eigenvalue 3347654, and the storing unit IP 6  corresponds to the eigenvalue 123456. Then the processing unit B 2  transfers the eigenvalues 2245681, 86721 to the storing unit IP 1 , the eigenvalue 3347654 to the storing unit IP 4 , and the eigenvalue 123456 to the storing unit IP 6 . 
         [0044]    After received the eigenvalues 2245681, 86721, the storing unit IP 1  compares them with the internal eigenvalue table IP 1 ′ (as shown in  FIG. 5 ) and finds them in the table IP 1 ′, so the file blocks Block 2 , Block 4  corresponding to the two eigenvalues are returned to the processing unit B 2 . After received the eigenvalue 3347654, the storing unit IP 4  compares it with the internal eigenvalue table IP 4 ′ and finds it in the table IP 4 ′, so the file block Block 3  corresponding to the eigenvalue 3347654 is returned to the processing unit B 2 . After received the eigenvalues 123456, the storing unit IP 6  compares it with the internal eigenvalue table IP 6 ′ and finds it in the table IP 6 ′, so the file block Block 7  corresponding to the eigenvalue 123456 is returned to the processing unit B 2 . 
         [0045]    After received the file blocks Block 2 , Block 4 , Block 3 , Block 7  corresponding to eigenvalues 2245681, 86721, 3347654, 123456 returned from storing units IP 1 , IP 4 , IP 6 , the processing unit B 2  stores the above data in the buffer area, and adds the above eigenvalues to the eigenvalue table W 2 . Simultaneously, the processing unit B 2  sends back the above file blocks to the user end A 1 . After received the file blocks Block 2 , Block 4 , Block 3 , Block 7  returned by the processing unit B 2 , the user end A 1  recombines the file blocks Block 0 -Block 7  into the complete file based on the sequence of the eigenvalue set in the eigenvalue table Y. 
         [0046]    Partial data from the processing unit B 2  and partial data from the far-end storing units IP 1 , IP 4 , IP 6  by the download process will slightly increase the efficiency of Internet or Web utility. Since the file data completed the data cache preparation in the processing unit B 2 , the efficiency of the Internet or Web utility reaches to the top when a user reads the same file next time. Based on the security and protection of data, before sending eigenvalue set to the processing units, a user end needs to do chaotic processing for the sequence of an eigenvalue set, so that the processing unit is not able to obtain the sequence of the eigenvalue set to recombine the file even it obtains the entire eigenvalue set. 
         [0047]    As cited, the cloud data storage system can also provide a virus elimination process. In the process, the storing units IP 1 -IP 10  can take the responsibility of scanning the stored file blocks. If a virus data block is detected, the storing units IP 1 -IP 10  inform the user end A 1  the eigenvalues corresponding to the file data blocks containing the virus when the user end A 1  queries. Or the storing units IP 1 -IP 10  can actively inform all processing units B 1 -B 3  to establish a virus eigenvalue table in order to inform the user end when the user end A 1  queries. Thus, when a virus is detected, the cloud data storage system can proceed with treating the virus in real time to thereby prevent the virus from expanding, and thus substantially increase the speed of virus detection and elimination. 
         [0048]    Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.