JP5825940B2 - Distributed processing control system and control method thereof - Google Patents

Description

  The present invention relates to a distributed processing control system and a control method therefor, and more particularly to a technique suitable for use in processing data transmission / reception requests from a large number of client devices that exceed the processing capability.

  Due to advances in electronic computer technology, various software for enabling processing via a network has been installed in office equipment such as copiers and household equipment such as cameras. As a result, such a device can be connected as a client device to a network service on the Internet.

  When providing a network service to such a client device, it is necessary to use an Internet technology represented by URL or HTTP as a basis. URL is an abbreviation for UNIFORM RESOURCE LOCATOR, and is a description method that indicates the location of data existing on the Internet. The URL is composed of information access means, server address, port number, folder name, file name, and the like.

  HTTP is an abbreviation for HYPERTEXT TRANSFER PROTOCOL, and is a protocol used for transmitting and receiving data specified by a URL between a server device and a client device. Various data can be exchanged between the server device and the client device by HTTP. HTTP is standardized by IETF.

  On these Internet technologies, as a mechanism for processing access requests involving data transmission and reception from a large number of client devices at high speed, a plurality of server devices are prepared, and the processing load is dynamically distributed. There is a distributed processing technology. In addition, there is a distributed cache technology in which a data transmission / reception request is replaced by a dedicated cache device instead of a server device.

Japanese Patent Laid-Open No. 11-4261 JP-A-11-175471

  However, when devices sold in large quantities, such as compact digital cameras, connect to the network service as client devices, the server device side of the network service will also be able to distribute loads at a higher level than before. Performance is required.

  For example, the case of a service for chatting using a network compatible camera is typical. In such services, photo data must be handled in real time between multiple client devices.

  However, it is difficult to handle data transmission / reception requests from a large number of client devices at high speed only with the distributed processing technology and the distributed cache technology for improving the processing capability on the server device side. This is because there is a limit in accommodating access requests from client devices, which increase in proportion to the number of units sold, by improving the efficiency of server devices or cache devices that have a limited number of units. That is, it is difficult to improve the efficiency of the entire system only by means for improving the efficiency on the server device side. For this reason, in order to exceed this limit, the efficiency of the client device must also be improved by using some means.

  As a conventional technique for coping with such a problem in a data transfer request that is increasing in scale, there is an invention described in Patent Document 1 first. The present invention shows a means for providing a method for dynamically routing object requests in a cluster, which is a set of server devices, in order to improve cache efficiency and load balance of the server.

  In other words, the mapping of a plurality of server devices that responds to an access request to the object indicated by the URL can be dynamically adjusted. According to this, it is possible to solve the problem in efficiently sharing the responsibility for caching the object specified by the URL among a plurality of cache devices or server devices.

  This is a cache configuration method on the server device side. Therefore, although it is possible to improve the efficiency when the data indicated by the URL is distributed among a plurality of cache devices, it does not solve the problem of improving the overall efficiency including the client devices. This is because a client device whose state is not stable on the network cannot be determined in advance as a server device that responds to an access request.

  Furthermore, there exists invention of patent document 2 as another prior art. In the invention described in Patent Document 2, a rewrite server that manages characteristic information such as transfer speed and data type related to a URL rewrites the specified URL and returns it to the client device. As a result, a means for enabling the client device to access the data through the optimum route is shown.

  By using the present invention, the URL can be rewritten so that the client device is regarded as a cache device. As a result, there is a possibility that an access request from a client device can be processed not only on the server device side but also on another client device.

  However, for the same reason as in the invention described in Patent Document 1, it is impossible to permanently use data held by each client device that is unstable with respect to the energized state or the network connection state as a cache. Is possible. For this reason, as a means for realizing processing for complementing the processing capability of the server device, the problem that it cannot be used together with the server-side cache device is a major limitation.

As described above, it is difficult to process data transmission / reception requests from a large number of client devices that exceed the processing capability with only server devices and cache devices. In order to make this possible, it is conceivable that data exchange between client devices can be cached on the client device side as well. However, in this case, there is a problem that other client devices are not always usable.
SUMMARY OF THE INVENTION In view of the above-described problems, an object of the present invention is to be able to process data transmission / reception requests from a large number of client devices that exceed the processing capabilities of server devices and cache devices.

The distributed processing control system of the present invention has a plurality of client devices having a function of transmitting and receiving data through a network, a function of storing data transmitted and received from the client device, and a function of transmitting data to the client device in response to a request. A distributed processing control system in a network environment having a server device having a cache device that transmits data to the client device instead of the server device in response to a request from the server device. A data transmitting means for transmitting data to a server device having an address; a data receiving means for receiving data transmitted from the client device by the data transmitting means in the server device; and a data receiving means in the server device. Data storage means for storing the received data in the server device together with information on the client device that transmitted the data, and in the server device, cache transfer means for transferring the data stored in the data storage means to a cache device having a specific address; in the client device, the data request means for requesting data to the server device having a specific address, the server device, for the requested data by the data request unit from the client, maintains the data Ruki Based on the priority determined by the data response location priority determination means in the server device and the data response location priority determination means for determining the priority of whether to acquire from the cache device or another client device. can, cache devices, client machine A data request destination change requesting the client device to re-execute the data request means by generating a data request destination including a plurality of addresses and using the result as a response to the data request means of the client device. have a means, the data storage unit in the server apparatus, the information of the client device to store an information including the status of the client device address and the network connection, and data response places priority determination unit in the server device The priority of the address of the client device by the data transmitting means is determined by collating the information of the client device that has requested the data by the data requesting means with the information of the client device that has transmitted the data by the data transmitting means. Determine and request data in server equipment In the destination changing means, the data request destination to be generated is information indicated by a URL including addresses for a plurality of devices based on the priority, and the data request re-execution means in the client device sets the URL in advance. The client side data request response means for transmitting the data can be called to the client device that has generated the data by dividing the plurality of data based on a predetermined regularity, and the URL in the client device can be called. Is used without being divided, the cache side data request response means in the cache device can be called .

According to the present invention, since the generated data request destination is information indicated by a URL including addresses for a plurality of devices based on the priority, a large amount of data that exceeds the processing capability of the server device / cache device. Data transmission / reception requests from client devices can be processed.

It is a block diagram which shows the structural example of the client apparatus of embodiment of this invention. It is a block diagram which shows the structural example of a server apparatus and cache apparatus. It is a figure which shows the sequence of the process performed with a distributed processing control system. It is a figure which shows the other example of the sequence of the process performed with a distributed processing control system. It is a flowchart which shows an example of the process sequence in a server apparatus. It is a figure which shows the response data to a client apparatus in a server apparatus. It is a flowchart which shows the process sequence in a client apparatus. It is a figure which shows the state in the case of using the cache function by the side of a client apparatus. It is a block diagram which shows the hardware constitutions which can comprise each apparatus.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the accompanying drawings. The configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations. In this embodiment, the client device has a function of transmitting and receiving data through a network environment. The server device has a function of storing data transmitted and received from the client device and transmitting data to the client device in response to a request. The cache device has a function of transmitting data to the client device instead of the server device in response to a request from the server device.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of the main part of a client device showing the first embodiment of the present invention. Below, it demonstrates in detail regarding each part.
First, the client OS unit 101 is configured so that various hardware components constituting the client device 100 can be handled as computer resources in software. The presence of the client OS unit 101 eliminates the need for other software components that operate on the client device 100 to directly control hardware.

  Next, the client application unit 102 is a part having a function for providing a model-specific function in the client device 100 to the user. For example, if the client device 100 is a digital camera, it is software for performing control such as image capturing, storage, editing, and display.

  In the present embodiment, the client application 100 does not depend on what specific functions the client device 100 provides to the user. Therefore, the client application 100 is assumed to indicate individual characteristic functions of the client device. Part 102 is defined. That is, for example, if the client device 100 is a copying machine, a portion having functions such as paper copying, printing, and transmission is the function of the client application unit 102 in FIG.

  The client data request unit 103 receives a data transmission request from the client application unit 102 and requests the client data transmission unit 104 to perform processing. When the client application unit 102 makes a data transmission / reception request to another device through the network, the client data request unit 103 first accepts the request. Thereafter, the client data transmission unit 104 drives hardware that performs network processing through the client OS unit 101. That is, the client data request unit 103 converts the data format requested by the client application unit 102 into a format that can be processed by the client data transmission unit 104.

  For example, a case where the client device 100 is a digital camera device having a network upload function will be described as an example. At this time, the client application unit 102 requests the client data request unit 103 to upload the image as a file indicated by a specific URL on the network.

  The client data request unit 103 analyzes the URL and generates transmission data including a transmission destination such as an actual host name and an IP address and an image in a format compliant with HTTP. As described above, the client data request unit 103 is a part that provides data request means for requesting data to a server device having a specific address.

  In addition, when a URL including a plurality of addresses is received as a response to the data request issued in this way, the client data transmission unit 104 is controlled to take out a plurality of addresses from the received URL and access each of them. The process to do is also performed. That is, data request re-execution means is also provided. The data request re-execution means divides the above-mentioned URL into a plurality based on a predetermined regularity, thereby transmitting the data to the client device that generated the requested data. Request response means can be invoked.

  The client data transmission unit 104 transfers the processing request from the client data request unit 103 to the client OS unit 101. For example, the client OS unit 101 is controlled based on the transmission destination address and transmission data converted by the client data request unit 103. Specifically, control is performed such as opening a TCP / IP session and transmitting actual HTTP data. That is, it is a part that provides data transmission means for transmitting data to a server device having a specific address.

  The client data storage unit 105 is a part that performs processing for temporarily storing data handled by the client data request unit 103. In response to a data transmission request via the client data request unit 103, the client data storage unit 105 performs control for temporarily copying and storing the data. Further, in response to a request from the client data receiving unit 107, the client data transmission unit 104 is controlled again to transmit the data held in the client data holding unit 106 to the network.

  The client data holding unit 106 controls a storage area for the client data storage unit 105 to actually hold data. For example, a process for storing data in a format that can be reused later is executed in a non-volatile memory or hard disk built in the device.

  The client data receiving unit 107 receives a request issued from an external device. Requests from other devices on the network are received via the client OS unit 101 and input to the client data receiving unit 107. The client data receiving unit 107 that has received the data converts it into a format that can be processed by the client data storage unit 105.

  For example, a case where there is a connection by HTTP from an external device at the TCP / IP port number 80 established by the client OS unit 101 will be described. At this time, it is the role of the client data receiving unit 107 to analyze data such as an HTTP URL, header, or payload and transfer it to the client data storage unit 105. That is, the client data receiving unit 107 is a part that provides client-side data request response means for transmitting data in response to a data request issued from another client device.

  By providing the software configuration as described above, the client device 100 has a function of not only transmitting requests to other devices on the network but also receiving and processing requests from other devices. be able to.

  FIG. 2 is a block diagram showing a configuration of a main part in the server device / cache device showing the embodiment of the present invention. The server device and the cache device are configured by the same software, and function as a server device or a cache device depending on the role at the time of execution and deployment. For this reason, the software configuration diagram has the same contents. Each part will be described in detail below.

  First, the server OS unit 201 is basically the same as the client OS unit 101 of the client device 100. That is, various hardware components constituting the server device 200 can be handled as software resources as software. By including the server OS unit 201, other software components operating on the server device 200 do not need to directly control hardware.

  Next, the server application unit 202 is a portion having a function for providing a model-specific function in the server device 200 to the user. For example, if the server device 200 is a server for storing images, it is software for controlling image reception, storage, search, transmission, and the like.

  Since the present invention does not depend on what specific functions the server device 200 provides to the user, in the present embodiment, individual characteristic functions of the server device / cache device are provided. As shown, this server application unit 202 is defined. That is, for example, if the server device 200 is not an image storage server but a document storage server, a portion having functions such as document reception, storage, search, and transmission is the function of the server application unit 202 in the figure.

  The server data request unit 203 receives a data transmission request from the server application unit 202 and requests the server data transmission unit 204 to perform processing. When the server application unit 202 makes a data transmission / reception request to another device via the network, first, the server data request unit 203 accepts the request. Thereafter, the server data transmission unit 204 drives hardware for performing network processing through the server OS unit 201. In other words, the server data request unit 203 converts the data format requested by the server application unit 202 into a format that can be processed by the server data transmission unit 204.

  For example, the server application unit 202 of the server device 200 that is an image storage server will be described as an example. The server application unit 202 requests to download the image data on the network indicated by the specific URL as a file. At this time, it is the role of the server data request unit 203 to analyze the URL and generate transmission data for requesting an image in a format compliant with the transmission destination such as the actual host name and IP address.

  The server data transmission unit 204 transfers the processing request from the server data request unit 203 to the server OS unit 201. For example, the server OS unit 201 is controlled based on the transmission destination address and transmission data converted by the server data request unit 203. Specifically, control is performed such as opening a TCP / IP session and transmitting actual HTTP data.

  The server data control unit 205 functions as a configuration for performing characteristic processing of the present invention by controlling the server data request unit 203, the server data reception unit 207, and the server data holding unit 206. Data transmitted from another device is stored in the server data holding unit 206 by the server data receiving unit 207. Then, the server data control unit 205 provides a cache transfer means for transferring the stored data to another cache device having a specific address. This is because a plurality of server devices / cache devices can share a request for a large amount of data issued when a large amount of client devices exist on the network.

  In addition, the server data control unit 205 also provides data response location priority determination means for determining which device should acquire data when a client device requests data acquisition. The device in this case means any one of a server device, a cache device, and another client device that holds the data.

  Further, based on the priority determined by the data response location priority determination means, a data request destination including addresses of a plurality of server devices, cache devices, and client devices is generated. The result is used as a response to the data request means of the client device. Thus, the server data control unit 205 also provides a data request destination changing unit that requests re-execution of the data request unit that requests the client device to transmit again.

  Further, in the cache device storing the data by the cache transfer means, a means for responding when the data request re-execution means issues a request for acquiring the data from the client device is also provided. That is, the server data control unit 205 also provides a cache-side data request response means for transmitting the data.

  The server data holding unit 206 controls a storage area for holding data managed by the server data control unit 205. For example, processing for storing data in a non-volatile memory or hard disk built in the server device 200 in a format that can be reused later is executed. In addition to data such as images and documents, the stored data includes information for identifying the client that transmitted the data. That is, the server data holding unit 206 is a part that provides data storage means for storing data transmitted from a client device together with information about the client device.

  The server data receiving unit 207 receives a request issued from an external device. Requests from other devices on the network are received via the server OS unit 201 and input to the server data receiving unit 207. The server data receiving unit 207 that has received the data converts it into a format that can be processed by the server data control unit 205.

  For example, a case where there is an HTTP connection from an external device at the TCP / IP port number 80 established by the server OS unit 201 will be described. At this time, it is the role of the server data receiving unit 207 to analyze data such as an HTTP URL, header, or payload and transfer it to the server data control unit 205 as a request. That is, it is a part that provides data receiving means for receiving data transmitted from the client device.

  The server device 200 has a software configuration as described above. As a result, the server device 200 has a function of not only transmitting a request to another device on the network but also receiving and processing a request from another device.

  FIG. 3 is a diagram showing a processing sequence in the client device and the server device / cache device according to the embodiment of the present invention. In particular, it is a diagram showing the main parts related to the processing sequence when the cache function on the client device side is not used. That is, the interaction performed between each client device and the server cache device when the cache function on the client device side provided by the present invention is not used at all is shown.

Each of the camera device 301 and the camera device 302 is a client device characterized by having the software configuration described in FIG.
The server device 303 and the cache device 304 are a server device and a cache device, respectively, having the software configuration described in FIG.

  In FIG. 3, the camera device 301 and the camera device 302 are digital cameras. The server device 303 and the cache device 304 are devices for configuring a photo storage service for storing images stored in the camera devices 301 and 302. In addition, each of the devices 301 to 304 is connected by a network, and a unique address for identifying each device is given on the network.

  Next, with reference to FIG. 3, an example of processing of a photo archiving service composed of a camera device 301 that is a digital camera, a server device 303, and a cache device 304 will be described. A camera device 301 that is a digital camera takes a picture. The photograph is stored in a photograph storage service composed of the server device 303 and the cache device 304. Further, when the camera device 302, which is another digital camera, uses the photograph, the processing flow is as follows.

  First, when the camera device 301 which is a digital camera takes a photograph, in step 350, the photograph PIC1 is uploaded to the server device 303 constituting the image storage service. At this time, after the client application unit 102 in FIG. 1 performs shooting, the client data request unit 103 uses the data transmission unit that controls the client data transmission unit 104 and the client OS unit 101, so that processing on the client device side is performed. Is executed.

On the other hand, in the server device 303, the server OS unit 201 in FIG. 2 receives the request from the client device and transmits it to the server data receiving unit 207, so that the camera device 301 is uploaded to the server data control unit 205. Photo PIC1 is sent.
Next, in step 351, the server device 303 transfers the received photo PIC1 to the cache device 304.

Next, in step 352, the camera device 302, which is another digital camera that has not photographed the photo PIC1, issues a download request for using the photo PIC1 to the server device 303.
Next, in step 353, since the photo PIC1 has already been transferred to the cache device 304 in step 351, data address transmission processing for returning the address of the cache device 304 from the server device 303 to the camera device 302 is performed.
Next, in step 354, the camera device 302 requests the cache device 304 to download a photo corresponding to the information obtained in step 353.
Next, in step 355, the cache device 304 returns the data of the photo PIC 1 to the camera device 302. As a result, the camera device 302 can acquire the photograph PIC1 taken by the camera device 301.

  FIG. 4 shows a processing sequence in the client device and the server device / cache device according to the embodiment of the present invention. It is the figure which showed the main parts regarding the process in the case of using especially the cache function by the side of a client apparatus. That is, the interaction performed between each client device and the server cache device when the cache function on the client device side provided by the present invention is used is shown.

  When the camera device 301, which is a digital camera, takes a photograph, first, in step 450, the photograph PIC1 is uploaded to the server device 303 constituting the image storage service. At this time, the client application unit 102 in FIG. 1 constituting the camera device 301 performs photographing. Specifically, this process is executed by the client data request unit 103 using a data transmission unit that controls the client data transmission unit 104 and the client OS unit 101. At the same time, the photo PIC 1 is also stored in the client data holding unit 106 through the client data storage unit 105 of the camera device 301.

On the other hand, in the server device 303, the server OS unit 201 in FIG. 2 receives the request from the client device and transmits it to the server data receiving unit 207. As a result, the photo PIC1 uploaded by the camera device 301 is sent to the server data control unit 205.
Next, in step 451, the server device 303 transfers the received photo PIC1 to the cache device 304. At this time, the server data control unit 205 configuring the server device 303 executes the following processing.

  That is, the server data control unit 205 stores the photo PIC 1 transmitted from the client device by the server data receiving unit 207 in the server data holding unit 206. At this time, the address of the camera device 301 that has transmitted the photo PIC1 and the download start / end time are stored in association with the photo PIC1. Next, the photograph PIC1 is transferred to the cache device 304.

  The next step 452 is the same as step 352. In other words, the camera device 302, which is another digital camera that has not photographed the photo PIC 1, issues a download request for using the photo PIC 1 to the server device 303.

  In the next step 453, when the photograph PIC1 is transmitted to the camera device 302, the most suitable response place is determined. This is performed by the server data control unit 205 constituting the server device 303. An example of processing performed in the data response location priority determination unit for performing this processing is shown below, for example. The priority of the address of the client device by the data transmission unit is determined by collating the information of the client device that has requested the data by the data requesting unit with the information of the client device that has transmitted the data by the data transmission unit. The processing performed in the data response location priority determination unit will be described in more detail with reference to FIG.

  Step 453 in FIG. 4 shows a case where the data response location priority determination unit determines that the camera device 301 that has taken the photo PIC1 is the response location with the highest priority. In addition, a case where it is determined that the cache device 304 stored in step 451 is suitable as a place with the next highest priority is shown.

  Next, in step 454, a download URL is generated based on the address of the response location determined in step 453 and returned to the camera device 302. That is, a data request destination including addresses of the camera device 301 and the cache device 304 is generated based on the priority determined by the data response location priority determination means.

  Then, the result is set as a response URL to the data request means for the camera device 302. This requests the camera device 302 to re-execute the data request means. This process is performed by the server data control unit 205 in the server device 303. In FIG. 6 to be described later, the response URL generated in this step will be described together with the flowchart of FIG.

  Next, in step 455, the camera device 302 that has received the result of step 454 analyzes the response URL, and issues a download request for the photo PIC1 to the address of the determined camera device 301. This processing is performed in the client data request unit 103 in FIG.

  When a URL including a plurality of addresses is received as a response to the issued data request, the client data transmission unit 104 sets the client data request unit 103 to retrieve a plurality of addresses from the URL and access them. Control. Details of the processing performed in this step will be described with reference to FIG.

  Next, in step 456, the camera device 301 returns the data of the photo PIC1 as a response to the camera device 302. This is realized by the client data storage unit 105 in the camera device 301 using the photograph PIC1 stored in step 450 in the client data storage unit 106.

  In this way, the camera device 302 can acquire the photograph PIC1 taken by the camera device 301. In the sequence shown in FIG. 3, it is obtained from the cache device 304, but in the sequence shown in FIG. 4, the photograph PIC <b> 1 can be obtained from the camera device 301. In other words, when a large number of client devices exist on the network, the image download processing in FIG. 4 can be performed without concentrating the load on the cache device 304 as compared with FIG.

  Further, when the camera devices 301 and 302 are connected to a high-speed network and the cache device 304 is via a low-speed network, the time required for transferring the photo PIC1 can be shortened. Therefore, in the case of FIG. 4, as a result, the camera device 302 can process the photo PIC1 in a shorter time.

  FIG. 5 is a flowchart for explaining the processing procedure in the server device showing the embodiment of the present invention. 5 is a flowchart showing a characteristic processing flow in the server device 303 when the cache function on the client device side shown in FIG. 4 is used. That is, the flow of processing performed in step 452, step 453, and step 454 in FIG. 4 is shown in more detail.

First, in S511, a request for a photo PIC1 is received from the camera device 302.
Next, in S512, it is determined whether there is another client device that holds the photo PIC1. If there is another, the process proceeds to S513, and if not, the process proceeds to S517. In step 451 in FIG. 4, the server data control unit 205 stores the address of the camera device 301 that has transmitted the photo PIC1 and the photo PIC1 in the server data holding unit 206 in association with each other. Therefore, this determination process can be performed by using the information stored in the server data holding unit 206.

  Next, in S513, it is determined whether the client device that holds the data and the client device that has requested the data exist in the vicinity. If it exists in the vicinity, the process proceeds to S514, and if it does not exist, the process proceeds to S517. Here, the definition of the neighborhood is defined as a short network distance. That is, it is determined whether or not the connection between the camera device 302 that has requested the data and the camera device 301 that holds the data can be expected to be faster than the connection with the cache device 304.

  In this embodiment, whether or not the clients belong to the same subnet is used for this determination. For example, in FIGS. 3 and 4, since the address of the camera device 301 is 150.61.10.1 and the address of the camera device 302 is 150.61.10.2, these two devices exist in the same subnet. However, since the address of the cache device 304 is 10.10.10.2, it exists in a different subnet. Therefore, in this case, it can be determined that the camera device 301 is closer.

  Next, in S514, it is determined how far the upload start time of the photo PIC1 is from the current time. This is because even if the photo PIC1 is held in the camera device 301, if a certain amount of time has elapsed since the holding, the client device with limited computer resources may continue to hold data. Is taken into account. If the upload start time is recent, the process proceeds to S515, and if not, the process proceeds to S517.

  Next, in S515, the upload completion time of the photo PIC1 is confirmed. This takes into consideration the case where uploading of the data to the server device has not been completed. That is, if the step 450 for uploading the photo PIC1 from the camera device 301 to the server device 303 is not completed yet, the photo PIC1 does not exist in the cache device 304 yet. In this case, only the camera device 301 may be able to process the request of the camera device 302 that requires the photo PIC1 at this time. If the upload has been completed, the process proceeds to S516. If the upload has not been completed, the process proceeds to S518.

In S516, the process is performed when it is determined that the photo device PIC1 is held by the camera device 301 that is the generation source and the cache device 304 is also held. That is, a URL designating both the cache device 304 and the camera device 301 is generated as the location where the photo PIC1 is stored.
In S517, processing is performed when it is determined that the camera device 301 that is the generation source of the photo PIC1 is not in the vicinity or that there is a high possibility that the data has already been deleted. In this case, the URL is generated by designating only the cache device 304 as the location where the photo PIC1 is stored.
In S518, the process is performed when it is determined that the photo PIC1 exists only in the camera device 301 that is the generation source. In this case, the URL is generated by designating only the camera device 301 as the location where the photo PIC1 is stored.
In S519, a response URL as a download location is generated based on the location of the photo PIC1 determined in each of the above steps, and this is returned to the camera device 302.

  FIG. 6 is a diagram showing an example of response data to the client device in the server device showing the embodiment of the present invention. In particular, an example of response data to the client device corresponding to each state shown in the flowchart of FIG. 5 is shown.

Reference numeral 601 denotes a URL generated when the process goes through S516 in FIG. In this embodiment, since a plurality of addresses are mixed in a single URL, the address of the camera device 301 and the address of the cache device 304 are described using a special mark “._OPT_.”. Analysis of the URL generated by this method is processed by the client data request unit 103 in FIG.
Reference numeral 602 denotes a URL generated when the process goes through S517 in FIG.
Reference numeral 603 denotes a URL generated when the process goes through S518 in FIG.

  FIG. 7 is a flowchart for explaining the processing procedure in the client device according to the embodiment of the present invention. In particular, a flow relating to characteristic processing in the camera device 302 when the cache function on the client device side shown in FIG. 4 is used is shown.

  This process is a process executed in the client data request unit 103 in FIG. When a URL including a plurality of addresses is received as a response to the issued data request, a plurality of addresses are extracted from the URL and the client data transmission unit 104 is controlled to access each address.

First, in S711, a response URL indicating the location of the photo PIC1 is received from the server device 303. This is one of the contents shown in FIG.
Next, in step S712, the URL is analyzed to check whether a predetermined mark exists. If the mark exists, the process proceeds to S713, and if not, the process proceeds to S716. In the present embodiment, as shown in FIG. 6, “._OPT_.” Is used as a special mark, so it is determined whether or not this character string is included in the URL. If the mark exists, the process proceeds to S713, and if not, the process proceeds to S716.

  Next, in S713, when the mark exists, another address that is not the address indicated by the URL itself is extracted from the URL. For example, in 601 in FIG. 6, since the original address of the URL is 10.10.10.2, 150.61.10.1 cut out using the mark “._OPT_.” Is determined as another address.

  Next, in S714, a URL is constructed again from the extracted address, and the photo PIC1 is requested for the URL. That is, when 601 in FIG. 6 is returned in S711, the URL requesting the photograph PIC1 as a result of the analysis is http://150.61.10.1/PIC1.

  Next, in S715, it is determined whether or not the photograph PIC1 has been acquired by the URL. If the camera device 301 cannot be obtained, that is, if the camera device 301 cannot be accessed, or if the camera device 301 has not already held the photo PIC1, the process proceeds to the next S716.

  In S716, the photo PIC1 is acquired once again using the URL itself acquired in S711. That is, the URL in the case of 601 in FIG. 6 is http://10.10.10.2/PIC1._OPT_.150.61.10.1/PIC1. Since the address indicated as the URL is the cache device 304, the photo PIC1 is requested from the cache device 304.

  FIG. 8 shows a data state and a network connection state in the client device and the server device / cache device according to the embodiment of the present invention. In particular, FIG. 5 is a diagram showing a state when the cache function on the client device side in FIG. 4 is used.

The camera device 301 and the cache device 304 are connected via a network 801.
The client data holding unit 106 of the camera device 301 stores a photographed photo PIC1. Further, the photograph PIC1 can be accessed from an external device through the network 801 at http://150.61.10.1/PIC1 which is a URL indicated by 603 in FIG.

  The cache device 304 also holds the same photo PIC1 in the server data holding unit 206. Further, the photograph PIC1 can be referred to through both the two different URLs 601 and 602 in FIG. 6 through the network 801. At this time, 601 is http://10.10.10.2/PIC1._OPT_.150.61.10.1/PIC1. Reference numeral 602 denotes http://10.10.10.2/PIC1.

  In addition, the server data holding unit 206 of the cache device 304 also holds the transmission source client, upload start time, and upload completion time attached to the photo PIC1 in order to enable the processing in the flowchart shown in FIG. Yes.

  FIG. 9 is a block diagram showing a computer device 900 that is hardware capable of configuring the client device and the server device / cache device according to the embodiment of the present invention.

  In FIG. 9, reference numeral 901 denotes a CPU that controls the entire computer apparatus 900. A ROM 902 stores programs and parameters that do not need to be changed. A RAM 903 temporarily stores programs and data supplied from an external device. Reference numeral 904 denotes an external storage device including a hard disk, a memory card, and the like that are fixedly installed in the computer apparatus 900. Reference numeral 905 denotes an I / F with an input device such as a pointing device or a keyboard that receives user operations and inputs data. Reference numeral 906 denotes an I / F with an output device for displaying data held by the computer apparatus 900 and supplied data. Reference numeral 907 denotes a network I / F for connecting to a network line such as the Internet. A system bus 908 connects the units 901 to 907 so that they can communicate with each other.

  According to the above-described embodiment, it is possible to process a data transmission / reception request from a large number of client devices that exceed the processing capability of the server device / cache device. That is, the exchange of data between client devices can be cached and used mutually. At this time, data existing in another client device that is not always available can be identified and referenced. Further, it can be used together with the cache processing in the server device / cache device which has been used conventionally.

  In the above-described embodiment, the example in which the distributed processing control system is configured by two client devices, one server device, and one cache device has been described. However, the number of client devices may be three or more. The server device and the cache device may be two or more.

Although the first embodiment has been described above, a different second embodiment is also conceivable in the following part of the first embodiment.
(Second Embodiment)
The part for determining whether or not the client device holding the data in S513 and the client device that has requested the data exist in the vicinity described in FIG. 5 in the first embodiment is as follows. It may be different as follows.

  In the first embodiment, the definition of the neighborhood is a closer network distance. That is, in order to determine whether or not the client device can be expected to be faster than the cache device, whether or not the clients belong to the same subnet is used. However, in the second embodiment, this determination is performed by actually transmitting and receiving ICMP packets and the like and measuring the elapsed time.

  More specifically, the data request time when another client device has requested data by the data requesting unit is compared with the data transmission time at which the client transmitted the corresponding data by the data transmitting unit. When the data transmission time and the data request time are close to each other, the priority regarding the address of the client device in the data request destination changing unit is increased. Further, when a considerable time has elapsed from the data transmission time to the data request time, the priority related to the address of the client device is lowered.

  Thereby, the measurement accuracy of the network-like distance can be further improved as compared with the first embodiment. However, there is a possibility of increasing network traffic as compared to the first embodiment. In some cases, the client device and the server device / cache device are not permitted to pass the packet mainly for security reasons. For this reason, the second embodiment does not replace the technique of the first embodiment.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (computer program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various computer-readable storage media. Then, the computer (or CPU, MPU, etc.) of the system or apparatus reads out and executes the program.

DESCRIPTION OF SYMBOLS 100 Client apparatus, 101 Client OS part, 102 Client application part, 103 Client data request part, 104 Client data transmission part, 105 Client data storage part, 106 Client data holding part, 107 Client data receiving part, 200 Server apparatus, 201 Server OS unit, 202 server application unit, 203 server data request unit, 204 server data transmission unit, 205 server data control unit, 206 server data holding unit, 207 server data reception unit

Claims (6)

A plurality of client devices having a function of transmitting and receiving data through a network, a server device having a function of storing data transmitted and received from the client device and transmitting data to the client device in response to a request, and a server device A distributed processing control system in a network environment having a cache device that transmits data to a client device instead of a server device upon request,
A data transmission means for transmitting data to a server device having a specific address in a client device having a specific address;
In the server device, data receiving means for receiving data transmitted from the client device by the data transmitting means;
In the server device, the data storage means for storing the data received by the data receiving means in the server device together with the information of the client device that has transmitted the data;
In the server device, cache transfer means for transferring data stored in the data storage means to a cache device having a specific address;
In the client device, data request means for requesting data to the server device having a specific address;
In the server device, to the data requested by the data request means from the client, determines the data response places the priority of how such should be obtained from any of the data holds the Ruki Yasshu device or another client device Priority determination means;
In the server device,-out based on the priorities determined by the data response places priority determination unit, cache device generates data request destination including a plurality of addresses of the client device, the data request means of the results client device by the responses to, have a data request destination changing means for requesting to re-execute the request means again data to the client device,
In the data storage means in the server device, the information of the client device to be stored is information including the address of the client device and the network connection status, and
The data response location priority determination unit in the server device compares the information of the client device that has requested the data by the data request unit with the information of the client device that has transmitted the data by the data transmission unit, thereby Determine the priority of the address of the client device by the transmission means,
In the data request destination changing means in the server device, the generated data request destination is information indicated by a URL including addresses for a plurality of devices based on the priority, and
Client-side data for transmitting the data to the client device that generated the data by dividing the URL into a plurality of data based on a predetermined regularity in the data request re-execution unit in the client device Request response means, and
A distributed processing control system characterized in that, when the URL is used as it is without being divided in a client device, a cache-side data request response means in the cache device can be called . In the data response location priority determination means in the server device, the data request time when the data request means requests another data from the data request means and the data transmission time when the data is transmitted by the client by the data transmission means. When the data transmission time and the data request time are close to each other, increase the priority regarding the address of the client device in the data request destination changing means, and
2. The distributed processing control system according to claim 1, wherein when a considerable time elapses from the data transmission time to the data request time, the priority regarding the address of the client device is lowered . In the client device, a data request re-execution unit that extracts the address of the cache device and the client device from a plurality of addresses specified by the data request destination changing unit, and executes the data request again to each of the devices ,
In the client device that generated the data, a client-side data request response unit that transmits the data in response to the data request re-execution unit issuing the data acquisition request from another client device ;
In the cache device storing the data transferred by the cache transfer unit, a cache for transmitting the data in response to the data request re-execution unit issuing the data acquisition request from the client device 3. The distributed processing control system according to claim 1 , further comprising: a side data request response unit . The distributed processing control system according to claim 1, wherein a plurality of server devices and a plurality of cache devices are connected to the network . A plurality of client devices having a function of transmitting and receiving data through a network, a server device having a function of storing data transmitted and received from the client device and transmitting data to the client device in response to a request, and a server device A control method of a distributed processing control system in a network environment having a cache device that transmits data to a client device instead of a server device upon request ,
In a client device having a specific address, a data transmission step of transmitting data to a server device having a specific address ;
In the server device, a data reception step of receiving data transmitted in the data transmission step from the client device ;
In the server device, the data storage step of storing the data received in the data reception step in the server device together with the information of the client device that has transmitted the data ;
In the server device, a cache transfer step of transferring the data stored in the data storage step to a cache device having a specific address ;
In the client device, a data request process for requesting data to the server device having a specific address ;
In the server device, the data response location priority is used to determine whether the data requested in the data request process from the client should be acquired from the cache device holding the data or from another client device. Degree determination step ,
In the server device, a data request destination including a plurality of addresses of the cache device and the client device is generated based on the priority determined in the data response location priority determination step, and the result is returned to the data request step of the client device. And a data request destination changing process for requesting the client device to re-execute the data request process, and
In the data storage process in the server device, the client device information to be stored is information including the address of the client device and the network connection status, and
The data response location priority determination step in the server device compares the information of the client device that has requested the data in the data request step with the information of the client device that has transmitted the data in the data transmission step. Decide the priority of the address of the client device in the transmission process,
In the data request destination changing process in the server device, the generated data request destination is information indicated by a URL including addresses for a plurality of devices based on priority, and
Client-side data for transmitting the data to the client device that generated the data by dividing the URL into a plurality of data based on a predetermined regularity in the data request re-execution process in the client device The request response process can be invoked, and
A control method for a distributed processing control system , wherein when a URL is used as it is in a client device without being divided, a cache-side data request response process in the cache device can be called . A plurality of client devices having a function of transmitting and receiving data through a network, a server device having a function of storing data transmitted and received from the client device and transmitting data to the client device in response to a request, and a server device A program that causes a computer to execute a control method of a distributed processing control system in a network environment having a cache device that transmits data to a client device instead of a server device upon request ,
In a client device having a specific address, a data transmission step of transmitting data to a server device having a specific address ;
In the server device, a data reception step of receiving data transmitted in the data transmission step from the client device ;
In the server device, the data storage step of storing the data received in the data reception step in the server device together with the information of the client device that has transmitted the data ;
In the server device, a cache transfer step of transferring the data stored in the data storage step to a cache device having a specific address ;
In the client device, a data request process for requesting data to the server device having a specific address ;
In the server device, the data response location priority is used to determine whether the data requested in the data request process from the client should be acquired from the cache device holding the data or from another client device. Degree determination step ,
In the server device, a data request destination including a plurality of addresses of the cache device and the client device is generated based on the priority determined in the data response location priority determination step, and the result is returned to the data request step of the client device. And a data request destination changing process for requesting the client device to re-execute the data request process, and
In the data storage process in the server device, the client device information to be stored is information including the address of the client device and the network connection status, and
The data response location priority determination step in the server device compares the information of the client device that has requested the data in the data request step with the information of the client device that has transmitted the data in the data transmission step. Decide the priority of the address of the client device in the transmission process,
In the data request destination changing process in the server device, the generated data request destination is information indicated by a URL including addresses for a plurality of devices based on priority, and
Client-side data for transmitting the data to the client device that generated the data by dividing the URL into a plurality of data based on a predetermined regularity in the data request re-execution process in the client device The request response process can be invoked, and
A program for controlling a computer so that a cache-side data request response process in a cache device can be called when the URL is used without being divided in a client device .

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