JP3963508B2 - File search system and file holding server - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information search system and a file holding server that perform file transfer from a server connected to a network to a client terminal.
[0002]
[Prior art]
Conventionally, FTP (File Transfer Protocol) has been widely used as a means of using programs and data files (collectively referred to as files as necessary) held by a remote computer. There is a method called Protocol.
[0003]
FTP is an upper protocol of TCP / IP for transferring files between a host computer on a network called an FTP server and a client computer. When using FTP, the FTP server of the network group to which the own node (node to which the client computer belongs) belongs and the FTP server of the network group to which the target file belongs are interposed. FTP is a service of a client / server format, and the FTP client issues a file transfer instruction to the FTP server. Then, the FTP server confirms from the login ID and password whether the user has access authority to the FTP server.
[0004]
[Problems to be solved by the invention]
However, in the above file transfer method, when the target file is obtained from the FTP server, if the access to the FTP server is congested, the access itself is denied or the time required for the file transfer becomes very long. There is a problem that it is.
[0005]
By the way, the Internet is used on a global scale, and personal computers whose functions are limited only to the function of connecting to the Internet have been developed. In the future, it is considered that so-called network computers, in which useless hardware is saved as much as possible so that it can be used as a portable terminal and necessary software is obtained from a network each time it is used, are becoming popular. In such a usage mode, the above-mentioned problem is quite fatal to the system.
[0006]
Therefore, there is a demand for a server / client type file search system capable of effectively utilizing network resources and transferring a file to the client side quickly, and a file holding server as a component thereof. There is also a need for a server / client type file search system and a file holding server that can easily check revisions of files held by the server.
[0007]
[Means for Solving the Problems]
  In order to solve the above problems, the first aspect of the present invention connects one or a plurality of client terminals.RuConnected on the networkMultiple serverse,the aboveIn response to a file transfer request from a client terminalthe aboveIn the file search system that searches the file holding server that holds the requested file from the multiple servers via the user side server connected to the client terminal, and performs the file transfer as follows. It is characterized by that.
[0008]
  That is, the original fileOr duplicate fileAfter referring to the file information including at least the identification code of the original file or the duplicate file and the server name where the original file or the duplicate file to be transferred exists, The file search system that makes a file transfer request to the indicated server, and the server that holds the original fileAbove user sideEvery time the file information is referenced from the server,No originalA file reference was made to the server name item where the file exists.Above user sideRename and manage the server name, and keep duplicate filesRuOverIs the above user sideIn response to a file transfer request given by the server, the file information contains an identification code indicating that the file is a duplicate and the original fileAbove user sideAfter adding the server name to the file and transferring it, delete the file and file information held by itself,Above user sideThe server sends the file and file information returned in response to the file transfer request.The above file transfer request was madeAlong with sending to the client terminal, the returned file and file information are retained, and a duplicate file is retained.RuIt is characterized by shifting to a server.
[0009]
  In the second aspect of the present invention, one or a plurality of client terminals are connected.RuConnected on the networkMultiple serverse,the aboveIn response to a file transfer request from a client terminalthe aboveIn the file holding server in the file search system that searches the file holding server holding the requested file from the plurality of servers through the user side server connected to the client terminal and performs file transfer, It is characterized by that.
[0010]
  That is,From the user side serverWhen there is a transfer request for a duplicate file that does not hold the original file, the file request consisting of an identification code that the file is a copy and a code that identifies the server where the original file exists is sent Add it to the received fileTo the above user side serverAfter transferring the file, delete the file and file information held by you and set the ownership of the duplicate file.Above user sideOn the serverMigrationIt is characterized by making it.
[0011]
According to the first and second aspects of the present invention, the file once requested for file transfer is transferred and held in the user side server connected to the client terminal. If there is a transfer request for the same file from the client terminal, the server that holds the original file can transfer the file from the server that holds the duplicate file after referring to the file information on the server that holds the original file. Can be reduced. Since the file information is much smaller than the file itself, the load of file reference is extremely small. Therefore, the file transfer can be quickly performed as a whole.
[0012]
Further, when a server holding a duplicate file receives a transfer request from another server, the file and file information are transferred to the server, and then the file is deleted. Therefore, if a server that holds a duplicate file receives a transfer request from another server, it passes the ownership of the file, and it is less likely to keep a duplicate file that is not accessed frequently by its own client. Server load can be reduced.
[0013]
Since the file information for identifying the server where the original file exists is added and file transfer is performed, it is possible to always grasp the server where the original file exists, and to directly connect to the server where the original file exists if you want the latest file. You can get it by accessing.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a file search system and a file holding server according to the present invention will be described with reference to the drawings.
[0015]
As shown in FIG. 2, the file search system of this embodiment includes a plurality of servers S (S1 to S4) connected to a network N, and one or a plurality of client terminals C (C11) connected to the servers S, respectively. ˜C1n, C21˜C2m,...)) And is constructed on the premise of a client / server type network system.
[0016]
When referring to and transferring a file, the client terminal C, a server connected to the client terminal (referred to herein as a “user-side server”; represented in FIG. 2 by S but hereinafter denoted by the symbol US) and file (Referred to herein as a “file holding server”; represented by S in FIG. 2 but hereinafter denoted by the symbol FS) is substantially used. Note that the user side server may be a file holding server, and conversely, the file holding server may be a user side server. In FIG. 2, the server S1 having the database DB1 storing the file FILE1 is a file holding server, but there are actually many file holding servers in the network.
[0017]
When attention is paid to data transmission on the network, other servers may actually intervene between the user side server and the file holding server, but their operations are not related to the description of this embodiment. Other servers are not shown in the description.
[0018]
First, file information used for managing each file FILE, which is a feature of this embodiment, will be described.
[0019]
The file information FI consists of an identification code 1 bit indicating whether it is an original file or a duplicate file, and a final access server name 32 bits. Here, the duplicate file refers to a file acquired by transfer according to the transfer protocol of this embodiment. The last access server name represents the name of the server where the original file exists in the case of a duplicate file, and the name of the server that last referred to or transferred the file in the case of the original file. The final access server name is created when there is an access (reference or file transfer request) to the server holding the original file, and is added to the file to be transferred (hereinafter referred to as a duplicate file).
[0020]
In the file transfer according to the transfer protocol of this embodiment, only information reference and file transfer are allowed, and there is no security function by checking the user ID and password used in normal FTP.
[0021]
The request content in this embodiment is coded by a 2-bit code. When the upper bit R1 and the lower bit are R2, the upper bit R1 indicates a classification of a transfer request or an information request, and the lower bit R2 indicates the type of request target. Specifically, for example, it is classified as follows. 00 is a file transfer request for a binary file, 01 is a file transfer request for a text file, 10 is an information reference request for only the file attribute, and 11 is a request for all information including the file attribute and file location information. Indicates a reference request. The distinction between 00 and 01 is assumed to be used in a higher-level protocol, and is treated in the same manner in the processing in this embodiment. That is, there are three types of processing classifications: R1 = 0, R1R2 = 10, and R1R2 = 11.
[0022]
First, the file reference function will be described. The information that can be referred to is the file information FI described above, and the file size and creation date and time that are the attributes of the file.
[0023]
As shown in FIGS. 1A and 1B showing the inter-node interface at the time of information reference, when there is a file information reference request from the client terminal C, the user-side server US has a server FS that holds the requested file. Tell your navel request and announce your IP address at the same time. Information transmitted from the client terminal C to the user-side server US includes a user ID, an access destination server name, a request file name, a current directory of the client terminal, and a request content.
[0024]
In the user side server US, as shown in FIG. 3, the process ID assigning unit 31 assigns a process ID managed by the user side server US to the request (step 301), and uses it for each process ID until the process is completed. The user ID, request file name, and current directory information are stored in the processing information storage unit 32 as processing information (step 302). Further, the user-side server US adds its own IP address and processing ID to the request file name in the own IP address assigning unit 33 (step 303). Thereafter, the user-side server US decodes and reads the request content and transmits it (steps 304 and 305). Subsequent processing is executed depending on the request contents (step 306).
[0025]
First, a processing mode in the case of a reference request for all information will be described. When the server FS that holds the file receives the all information reference request, the file name extraction unit 41 extracts the requested file name from the information (packet) received from the user side server US as shown in FIG. 44. Further, the transfer destination server name extraction unit 42 extracts the transfer destination server name, that is, the IP address and the processing ID of the user side server US, and supplies them to the file information control table 43. A controller (not shown) determines whether the file name supplied to the file information storage unit 44 is a file that already has the file information FI or a file that has been accessed for the first time (step 401), and the file information FI already exists. If not, the file information creation unit 46 creates the file information FI (step 402). In the created file information FI, the file type is a code indicating the original file, and the final access server name is the self IP address.
[0026]
  Thereafter, the transfer destination server name is recognized with reference to the file information control table 43 (step 403), the file information is attached with reference to the file attribute from the file storage unit 47 (step 404), and the format of the file information FI is converted. After the unit 45 converts the data to be transmitted on the network, the file information FI is transmitted to the transfer destination server US on the network (step 405). At this time, the process ID is transferred together with the file information. After transfer, the file type is confirmed, and in the case of the original file, the file information FI is rewritten with the last access server name as the IP address of the server (steps 406 and 407)..
  File informationNewsAs shown in FIG. 5, the user-side server US that has received the processing ID fetching unit 51 extracts the processing ID, transmits it to the processing information storage unit 54 (step 501), and the file information extracting unit 52 extracts the file information. The file information is stored in the file information storage unit 53 (step 502). The processing information storage unit 54 reads the user ID and current directory stored according to the processing ID, and transfers the file information FI to the current directory of the client terminal of the read user ID (step 503). Thereafter, the processing information stored in the processing information storage unit 54 is deleted (step 504). As described above, all information regarding the file can be referred to by the client terminal C..
  Next, a processing mode in the case of a reference request for only file attributes will be described. When the server FS holding the file receives the information reference request only for the file attribute, the file FS refers to the file attribute from the file storage unit 62 as shown in FIG.News and(Step 602). Then this file informationNewsThe format conversion unit 63 converts the data to be transmitted on the network, and stores the file information on the transfer destination server US on the network.NewsTransmit (step 603). At this time, the process ID is also transferred together with the file information. File informationNewsAs shown in FIG. 7, the received user server US retrieves the process ID by the process ID retrieving unit 71 and transmits it to the processing information storage unit 73 (step 701), retrieves the file information by the file information retrieving unit 72, The file attribute information is transferred to the client terminal C as file information FI (step 702). Thereafter, the processing information stored in the processing information storage unit 73 is deleted (step 703). As described above, file attribute information can be referred to by the client terminal C.
[0027]
Next, the file transfer operation will be described. There are two types of file transfer: file transfer from a server holding an original file and file transfer from a server holding a duplicate file.
[0028]
First, file transfer from a server holding an original file will be described with reference to FIGS.
[0029]
The client terminal C issues a file transfer request to the user side server US. This file transfer request includes the user ID, the access destination server name, the requested file name, and the current directory of the client terminal C. In the user side server US, as shown in FIG. 3, the process ID assigning unit 31 assigns a process ID managed by the user side server US to the request, and a user ID and a request file for each process ID until all the processes are completed. The name and current directory information are stored in the processing information storage unit 32 as processing information. Further, the user-side server US adds its own IP address and processing ID to the requested file name in its own IP address assigning unit 33 and transmits it to the server FS holding the file.
[0030]
When the server FS that holds the file receives the request, as shown in FIG. 8, the file name extraction unit 81 extracts the requested file name from the information (packet) received from the user side server US, and the file information storage unit 84 To supply. Further, the transfer destination server name extraction unit 82 extracts the transfer destination server name, that is, the IP address and processing ID of the user side server US, and supplies them to the file information control table 83. A controller (not shown) determines whether the file name supplied to the file information storage unit 84 is a file already having the file information FI or a file accessed for the first time (step 802), and the file information FI already exists. If not, the file information creation unit 86 creates the file information FI (step 803). In this file information FI, the file type is a code indicating the original file, and the final access server name is the self IP address.
[0031]
Next, the transfer server name is recognized with reference to the file information control table 83 (step 804), and the file and file information FI are converted into data to be transmitted on the network by the format conversion unit 85. Next, the file information FI of the file to be transmitted is determined (step 805). In this case, since the file is transferred from the server holding the original file, the file information FI is rewritten to its own IP address, and then the file and the file information FI are transmitted together with the process ID to the user side server US (steps 806 and 807). Thereafter, the file information FI is rewritten and stored in the address of the transfer destination server US which is the final access server name (step 809). Thereby, it is possible to notify the next access person that the duplicate file also exists in the transfer destination server US.
[0032]
In the user side server US that has received the file transfer, as shown in FIG. 9, the process ID extracting unit 91 extracts the process ID, transmits it to the processing information storage unit 92 (step 901), and the file information extracting unit 93 The information FI is extracted, and it is determined whether the original of the file information FI received by the original / replication identification unit 94 and the copy identification code are a code indicating an original file or a code indicating a duplicate file (step 902). In this case, since the transferred file is treated as a duplicate file, the original and duplicate identification code are rewritten from the code indicating the original file to the code indicating the duplicate file (step 903). The file information FI is stored in the file information control table 96 (step 904), and the file extracted by the file extraction unit 95 is stored in the file storage unit 98 (step 905). The processing information storage unit 92 reads the user ID and current directory stored in accordance with the processing ID, and transfers the file to the current directory of the client terminal of the read user ID (step 906). Thereafter, the processing information stored in the processing information storage unit 54 (see FIG. 5; the same as 92) is deleted. Thus, the transfer of the file to the client terminal C is completed.
[0033]
Next, file transfer from a server having a duplicate file will be described. Since the operation up to step 805 in FIG. 8B is the same as the file transfer from the server having the original file, the description thereof is omitted.
[0034]
In step 805, since the file is transferred from the server having the duplicate file, the file and the file information FI are transmitted to the user side server US together with the process ID (step 808), and the post-transmission file and the file information FI are deleted (step 808). 810).
[0035]
The operation of the user-side server US that has received the file transfer is basically the same as the file transfer from the server having the original file, but since it is determined as a duplicate file in step 902, the file information is not rewritten. .
[0036]
Although the individual operations have been described above, an example of the entire operation will be described with reference to FIGS. 10 and 11 for easy understanding.
[0037]
When the original file 1 (abbreviated as “F-1”) in the database DB of the first server S1 shown in FIG. 2 is transferred to the client A (C21) connected to the second server S2, the server The case where the file 1 (F-1) transferred to S2 is transferred to the client B (C31) connected to the server S3 will be described as an example. In the timing charts of FIGS. 10 and 11, the leftmost column lists the timing, and the subsequent columns describe the operation of each server or client in the order of operation from top to bottom.
[0038]
Prior to transferring the original file 1 (F-1) in the database DB1 of the first server S1 to the client A (C21) connected to the second server S2, the client A (C21) sends the first server The case of referring to S1 is shown in timings 1 to 11 in FIG.
[0039]
First, at timing 1, the client A issues a request for all information on file 1 to the server S 2. The server S2 transfers the reference request to the server S1 (timing 2). Receiving the transfer request, the server S1 creates the file information FI (timing 3, 4). Here, it is assumed that the reference request is received for the first time. The contents of the file information FI are (original, self IP address, that is, S1) (timing 4). This file information FI is transferred to the server S2 (timing 5). In this case, the last access server name of the file information FI is rewritten to the server S2 (timing 6). The server S2 receives the transfer of the file information FI and transfers it to the client A (timing 7, 8, 9). The client A can know that the file is stored in the server S1 as an original from the transferred file information FI.
[0040]
Client A subsequently transfers file 1. Since it can be known from the transferred file information FI that the file is stored as an original in the server S1, a request is sent from the server S1 to the server S2 to transfer the file 1 (timing 12). The server S2 transfers the transfer request to the server S1 (timing 13). The file information FI of the server S1 that has received the transfer request is determined at timing 6 (original, S2) (timing 15). The server S1 once rewrites this file information FI. The content to be rewritten is to rewrite the last access server name to its own IP address, that is, S1 in order to notify the transfer destination of the server where the original file exists (timing 16). Then, the file, file information FI, and process ID are transferred to the server S2 (timing 17, 18). Thereafter, the last access server name is rewritten to the server S2 that stores the duplicate file in order to remember the server that stores the duplicate file in the file information FI stored by itself (timing 19). The server S2 that has received the transfer has the code indicating the original file attached to the file information FI that has received the transfer, and rewrites it with a code that indicates the duplicate file, and saves the duplicate file and the file information FI (timing 20 to 20). 23). Then, the duplicate file is transferred to the client A (timing 24).
[0041]
At this point, the file 1 exists in the original server S1 and the duplicate file server S2. The file information FI of the original server S1 is (original, S2), and the file information FI of the duplicate file server S2 is (replicated, S1). Therefore, the other server that referred to the original server S1 can know that the replica is in the replica file server S2, and the other server that referred to the replica file server S2 knows that the original is in the original server S1. This makes it easier to deal with revisions and the like.
[0042]
Next, the operation when there is a transfer request for the same file 1 from the client B (C31) connected to the third server S3 in this state will be described.
[0043]
  The client B (C31) issues a reference request for the file 1 to the server S3 (timing 26). The server S3 transfers the reference request to the server S1 (timing 27). Upon receiving the transfer request, the server S1 confirms the file information FI (timing 28). In this case, the file information FI already exists, and the contents of the file information FI are (original, server having the duplicate file, that is, S2) (FIG.Timing 19). This file information FI is transferred to the server S3 (timing 30). The last access server name of the file information FI is rewritten to the server S3 in this case (timing 31). The server S3 receives the transfer of the file information FI and transfers it to the client B (timing 32 to 33).
[0044]
The client B can know that the file is stored as a copy in the server S2 from the transferred file information FI. Therefore, the client B decides to transfer a file from the server S2 instead of the server S1 where the original exists. A request is made to the server S3 to transfer the file 1 from the server S2 (timing 37). The server S3 transfers the transfer request to the server S2 (timing 38). Receiving the transfer request, the server S2 (timing 39) transfers the file, file information FI, and processing ID to the server S3 (timing 40, 41). Thereafter, the file stored by itself and the file information FI are deleted (timing 42). Receiving the transfer, the server S3 stores the transferred copy file and the file information FI (timing 43 to 45). The duplicate file is transferred to the client B (timing 46, 47). Accordingly, this time, the server S3 becomes a storage location of the duplicate file. This is as if the ownership of the duplicate file is transferred to the next transfer destination server for each file transfer. Also in this case, by using the file information FI, the server that always saves the original file can grasp the save destination of the duplicate file, and can also know the affiliation source of the original file at the duplicate destination.
[0045]
According to the above-described embodiment, a server / client type file search that makes effective use of network resources, enables quick file transfer to the client side, and allows easy confirmation of revisions of files held by the server. A system and a file holding server can be realized.
[0046]
The above embodiment is conscious of the Internet, but it goes without saying that the present invention can be applied to other networks.
[0047]
【The invention's effect】
As described above, according to the present invention, a server / client that can effectively use network resources, can quickly transfer a file to the client side, and can easily check a revision of a file held by the server. Type file retrieval system can be provided.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of exchange information when referring to information and transferring a file in the file search system according to the embodiment.
FIG. 2 is an explanatory diagram illustrating an example of a network to which the embodiment is applied.
FIG. 3 is an explanatory diagram of an operation at the time of a request from the client to the user side server according to the embodiment.
FIG. 4 is an operation explanatory diagram of a transfer source server when referring to all file information according to the embodiment;
FIG. 5 is an operation explanatory diagram of a transfer destination server when referring to all file information according to the embodiment;
FIG. 6 is an operation explanatory diagram of the transfer source server when referring to only the file attribute of the embodiment.
FIG. 7 is an operation explanatory diagram of the transfer destination server when referring to only the file attribute of the embodiment.
FIG. 8 is an operation explanatory diagram of a transfer source server when transferring file information according to the embodiment.
FIG. 9 is an operation explanatory diagram of a transfer destination server when transferring file information according to the embodiment;
FIG. 10 is a diagram illustrating reference and transfer from an original file server according to the embodiment.
FIG. 11 is a diagram illustrating reference and transfer from a duplicate file server according to the embodiment.
[Explanation of symbols]
C: client terminal, US: user side server, FS: file holding server, FI: file information, N: network.

Claims (3)

The connected servers on are connected one or a plurality of client terminals Rene Ttowaku example multiple Bei, the file transfer request from said client terminal, via the user-side server connected to the client terminal In the file search system for searching for a file holding server that holds the requested file from the plurality of servers, and performing file transfer,
The server that holds the original file or duplicate files, after performing the original file or duplicate files or identification code, including at least a reference file information of the presence server name of the original file or duplicate files to be transferred, the file A file search system that makes a file transfer request to a server indicated by a server name in information,
Server holding the original file, each receiving a reference of the file information from the user side server, to the user side server name item of the server name of performing a file reference to the presence of the original file in the file information While rewriting and managing,
Lusa over bar to retain the replicated file, the user side server to the file transfer request given from the user side server, the file as the file information is present in the identification code and the original file that is a duplicate After adding the name to the file and transferring it, delete the file and file information held by itself,
The server on the user side sends the file and file information returned in response to the file transfer request to the client terminal that made the file transfer request, and holds the returned file and file information, and holds a duplicate file. file search system, characterized in that the transition to be Lusa over server.   When the file that received the transfer request receives the first reference request, the server that holds the original file stores file information in which the identification code is the original file and the server name item in which the file exists is its own server. The file search system according to claim 1, wherein the file search system is created. The connected servers on are connected one or a plurality of client terminals Rene Ttowaku example multiple Bei, the file transfer request from said client terminal, via the user-side server connected to the client terminal In the file holding server in the file search system that searches the file holding server holding the requested file from the plurality of servers and performs file transfer,
When there is a transfer request for a duplicate file that does not hold the original file from the user side server, file information consisting of an identification code that the file is a duplicate and a code that identifies the server where the original file exists Is added to the file for which the transfer request has been received and transferred to the user side server, and then the file and file information held by itself are deleted,
A file holding server, wherein ownership of the duplicate file is transferred to the user side server.

Images