JP2005122358A - Web content delivery system, web content delivery program, and proxy server - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Web content delivery system which requires a short waiting period for a Web user and can be easily realized technically. <P>SOLUTION: The Web content delivery system is provided with a Web server 122 having Web contents 108 and mirror servers 123, 124 having Web contents the same as that of the Web server, and accesses the Web contents from a browser 101 through a proxy server 125. When a first file in the Web contents is requested to the Web server 122 from the browser 101 through a proxy server 125, the Web server transmits the requested file together with the URLs of the mirror servers to the proxy server. When another file of the Web content is requested from the browser, the proxy server 125 selects a server capable of responding from the Web server 122 and the mirror servers 123, 124 indicated by the URLs to receive the file. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of load balancing with a plurality of mirror servers, and in particular, a web that receives data from a server with a low load among servers of the WWW (World Wide Web, hereinafter abbreviated to the web) and distributes it to a browser. The present invention relates to a content distribution system, a web content distribution program, and a proxy server.

  With the rapid development of the Internet, the number of users increases rapidly, and the number of users who simultaneously use web content information also increases rapidly. In order to cope with such an increase in users, information providers have prepared mirror servers and are trying to deal with the load of web content distribution.

  An example of a conventional web content distribution system that realizes such load distribution is shown in FIG.

  In the web content distribution system using the conventional mirror server shown in FIG. 5, when downloading the web content 308 from the browser 301, first, the browser 301 issues a download request for the first file 309 of the web content 308.

  This download request reaches the proxy server 302 via the path 312. The proxy server 302 transmits the download request to the load distribution system 304 in the server system 303 via the path 313, the path 315 in the Internet network 314, and the path 316 that is the entrance to the server system 303.

  The load distribution system 304 investigates the load of the web server 305 having the web content 308 or the mirror server 306 or 307 of the web server 305, and selects the server with the lowest load and the route 317 or the route 318 or the route 319 as those routes. Use to download the file 309 in the web content 308.

  The downloaded file returns the path when the file is requested, and finally reaches the browser 301. Thereafter, the subsequent file 310 and file 311 of the web content 308 are downloaded in the same manner.

  As described above, the server system 303 provides a high-speed response to the browser 301 by distributing the access to the web content 308 into three by the load distribution system 304.

  An example of a load distribution method is described in, for example, Japanese Patent Application Laid-Open No. 2001-256208 (Patent Document 1).

  In this patent document 1, a means for balancing the load among a plurality of mirror servers is provided in the browser. This means includes a script analyzer for analyzing a script received by a browser, a script executor for connecting to each of a plurality of mirror servers, and measuring a response time of each server based on an analysis result from the script analyzer, and a response It consists of a selector that selects the mirror server with the shortest time.

  In the method disclosed in Patent Document 1, a script returned from a host server is analyzed with a browser, all of the mirror servers are connected, and the one with the shortest response time is selected. Data transmission / reception is performed.

As another load balancing method, a plurality of servers are installed, and if there is no response from the first server, switch to the next server, or if there is no response from the next server, further to the third server. A method of switching is proposed in Japanese Patent No. 3299521 (Patent Document 2).
JP 2001-256208 A Japanese Patent No. 3299521

  All of the conventional techniques described above have the following problems.

  In the case of the load distribution method in the web content distribution using the conventional mirror server shown in FIG. 5, the place where the load is distributed is only inside the server system. That is, in the case of this method, even if a very high speed LAN or server is used inside the server system, as shown in FIG. There is a problem that it takes a lot of time to deliver to the browser.

  In addition, there is a problem that an increase in cost and a decrease in availability (failure of the load distribution system) are caused by preparing the load distribution system.

  Furthermore, in the method of balancing the load among a plurality of mirror servers disclosed in Patent Document 1, the mirror server selection process is performed only at the first access, and the server is fixed for subsequent accesses. For this reason, when a communication trouble caused by the selected mirror server or its route occurs, it cannot be dealt with and the service to the user is reduced.

  In addition, in this method, it is necessary to provide a means for balancing the load among a plurality of mirror servers in the browser, and there is a problem that the browser needs to be improved.

  On the other hand, a technology for installing a plurality of servers shown in Patent Document 2 and switching the servers has been proposed. This technology was originally a technology for switching to another server when communication with the server could not be performed. Therefore, it is not a technology that enhances the service to users. Also in this method, the server selection process is performed only at the first access, and the server is fixed for subsequent accesses.

  A first object of the present invention is to solve the above-mentioned drawbacks of the prior art, a web content distribution system capable of selecting a server with a quick response time each time access can be performed by a proxy server, and web content It is to provide a distribution program and a proxy server.

  A second object of the present invention is to provide a web content delivery system, a web content delivery program, and a proxy server that do not require preparation of a large-scale and redundant load distribution system, can be easily introduced at a low cost, and are excellent in availability. It is to provide.

  To achieve the above object, the present invention comprises a web server having web content and a mirror server having web content having the same content as the web server, wherein the web content is accessed from a browser via a proxy server. In the content distribution system, when the first file in the web content is requested from the browser via the proxy server to the web server, the URL of the mirror server together with the requested file Is sent to the proxy server, and when another file of the web content is requested from the browser, the proxy server selects a server that can respond from the web server and the mirror server indicated by the URL. Receiving the file The features.

  According to the web content delivery system of the present invention of claim 2, the proxy server selects a server that responds within a predetermined time from the web server and the mirror server indicated by the URL, and stores the file. It is characterized by transmitting a request.

  According to the web content distribution system of the present invention of claim 3, the proxy server selects the server every time another file of the web content is requested from the browser.

  According to the web content distribution system of the present invention of claim 4, the web server returns the URL of the mirror server written in the HTTP header of the requested file.

  According to the web content distribution system of the present invention of claim 5, the proxy server deletes the description of the mirror server URL from the HTTP header of the file and transfers the file to the browser. A mirror server URL database describing the URL of the mirror server in correspondence with the URL is created.

  The present invention of claim 6 includes a web server having web content and a mirror server having web content having the same content as the web server, and the web content delivery is performed by a browser to access the web content via the proxy server. A web content delivery program that operates on the web server and the proxy server of the system and realizes load distribution in the web content delivery, wherein the web content delivery program of the web server passes through the proxy server from the browser When the first file in the web content is requested to the web server, the function of transmitting the URL of the mirror server together with the requested file to the proxy server is executed, and the proxy server web When the content distribution program requests another file of the web content from the browser, the content distribution program executes a function of selecting the server that can respond from the web server and the mirror server indicated in the URL and receiving the file It is characterized by doing.

  According to the present invention of claim 7, the web content distribution program of the proxy server selects a server that responds within a predetermined time from the web server and the mirror server indicated by the URL, and A function of transmitting a request is executed.

  According to the present invention of claim 8, the web content distribution program of the proxy server executes a function of selecting the server each time another file of the web content is requested from the browser. And

  According to the present invention of claim 9, the web content distribution program of the web server executes a function of entering and returning the URL of the mirror server in the HTTP header of the requested file.

  According to the present invention of claim 10, the web content distribution program of the proxy server deletes the description of the URL of the mirror server from the HTTP header of the file and transfers the file to the browser. A function of creating a mirror server URL database in which the URL of the mirror server is described in association with the URL is executed.

  The present invention of claim 11 comprises a web server having web content and a mirror server having web content having the same content as the web server, and the web content is distributed from the browser via the proxy server. The proxy server of the system, when the first file in the web content is requested from the browser, the URL of the mirror server is received together with the file requested from the web server, and other web content is received from the browser. When a file is requested, a server capable of responding is selected from the mirror server indicated by the web server and URL, and the file is received.

  According to the proxy server of the present invention of claim 12, a request for the file is transmitted by selecting a server that responds within a predetermined time from the web server and the mirror server indicated by the URL. And

  According to a proxy server of the present invention of claim 13, the server is selected each time another file of the web content is requested from the browser.

  According to the proxy server of the present invention of claim 14, when the URL of the mirror server is written in the HTTP header of the file and returned from the web server, the URL of the mirror server is described from the HTTP header of the file. It deletes and transfers the file to the browser, and creates a mirror server URL database describing the URL of the mirror server in correspondence with the URL of the web server.

  According to the web content delivery system, web content delivery program, and proxy server of the present invention, the following effects are achieved.

  First, since a proxy server selects a server for downloading web content for each download request, even if the response from the first selected server is slow, another mirror server with a fast response , Prompt distribution of information becomes possible. That is, by distributing the route from the proxy server, a high-speed response to a request from the browser can be realized even when a part of the load on the Internet network is high. In addition, even if a line trouble or a server trouble occurs, it is not easily affected, and the service to the user is improved.

  Secondly, since the server selection process is performed by the proxy server, it is not necessary to prepare a large-scale and redundant load distribution system, and it is easy to introduce at low cost and has high availability. A system can be realized.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings. In the web content distribution system according to the present invention, a proxy server responds within a certain time from among a web server and a plurality of mirror servers. The process of transferring the file received from the mirror server to the browser is executed every time the file is accessed.

  Since the server is selected every time it is accessed, even when the speed of the server selected first decreases, it is possible to always download from the server with a quick response. In addition, even if a line trouble or a server trouble occurs, it is not easily affected, and the service to the user is further improved.

  FIG. 1 is a block diagram showing a configuration of a web content distribution system according to a first embodiment of the present invention. Referring to FIG. 1, the web content distribution system of the present embodiment includes a browser 101, a proxy server 125, a web server 122 having web content, and mirror servers 123 and 124 having web content having the same content as the web server. It is configured to be connected via the Internet network 120.

  The browser 101 is connected to the proxy server 125 via a route 112, and the proxy server 125, the web server 122, the mirror server 123, and the mirror server 124 are connected to the Internet network 120 via a route 113, a route 117, a route 118, and a route 119, respectively. Yes.

  Further, the route 113 serving as the entrance of the proxy server 125 is the route 113, route 117 serving as the entrance of the web server 122, the mirror server 123, and the mirror server 124 via the route 114, route 115, and route 116 in the Internet network 120. , Path 118 and path 119 are connected.

  Web content distribution in this web content distribution system is processed by software (web content distribution program) executed on a web server 122 and a proxy server 125 which are computer devices (CPUs) capable of program control. This web content distribution program is stored in a magnetic disk, a semiconductor memory, or other recording medium, loaded from the recording medium to a computer device, and controls the operation of the computer device to execute the web content distribution processing described below. .

  The web server 122 is installed with a web content distribution program 127 for a web server according to the present invention. Further, the proxy server 125 is installed with a web content distribution program 128 for the proxy server according to the present invention.

  Note that the web server 122, the mirror server 123, and the mirror server 124 may be located at remote locations. In this case, since the route in the Internet can be distributed, the distribution efficiency can be further increased.

  Next, the operation according to the present embodiment will be described with reference to the drawings. FIG. 2 is a diagram illustrating an operation performed by the web content distribution system according to the present embodiment, and illustrates a file transfer operation of web content. FIG. 4 is a flowchart for explaining the operations of the proxy server and the web server according to this embodiment. Hereinafter, description will be given with reference to FIG.

  When downloading the web content 108 from the browser 101, first, a download request for the first (first) file 109 in the web content 108 is issued from the browser 101. The download request is sent to the proxy server 125 via the path 112 (step 301).

The proxy server 125 transmits the download request to the web server 122 via the route 113, the route 114 and the route 117 in the Internet 120. (Step 302)
Here, when downloading the file 109 to the browser 101, the web server 122 describes the URLs of the mirror server 123 and the mirror server 124 in the HTTP header (step 303).

  The file 109 returns the route at the time of the download request of the file, and reaches the proxy server 125 (step 304).

  When the proxy server 125 transfers the received file 109 to the browser 101, the proxy server 125 deletes the URL descriptions of the mirror server 123 and the mirror server 124 from the HTTP header, and associates the mirror server 123 and the mirror server with the URL of the web server 122. A mirror server URL database 126 in which the URL of the server 124 is recorded is created (step 306). Thus, sending of the file 109 to the browser 101 is completed.

  FIG. 3 is a diagram showing a transfer operation of the second file in the web content 108.

  Next, the browser 101 issues a download request for the second file 110 of the web content 108, and reaches the proxy server 125 via the path 112. The proxy server 125 transmits a download request for the file 110 to the web server 122 in the same manner as when the download request for the file 109 is made.

  Here, when the load on the route 114, the route 117, and the web server 122 in the Internet network 120 is low and the response of the web server 122 is fast, the proxy server 125 transmits the file 110 downloaded from the web server 122 to the browser 101. .

  However, as shown in FIG. 3, when a response is not obtained within a certain time due to congestion of the route 114 in the Internet network 120 or the web server 122, the proxy server 125 refers to the mirror server URL database 126. From the list of mirror server URLs corresponding to the web server 122, one candidate for the request destination of the file 110 (mirror server 123 in the example of FIG. 3) is selected.

  The proxy server 125 transmits a download request for the file 110 to the selected mirror server 123. When the load on the route 115, the route 118, and the mirror server 123 in the Internet network 120 is low and a response is obtained within a certain time, the proxy server 125 transfers the file 110 downloaded from the mirror server 123 to the browser 101. .

  In the above embodiment, the response of the web server 122 is slow and the mirror server 123 shows a fast response. However, if the response of the mirror server 123 is slow and no response is obtained within a certain time, The proxy server 125 selects the next mirror server candidate from the mirror server URL database 126, and transmits a download request for the file 110 in the same manner as performed to the mirror server 123.

  As for the file 111 and the subsequent files included in the web content 108, the file downloaded from the mirror server with a quick response is transferred to the browser 101 by the same process as described above.

  If the proxy server 125 issues a download request having the same contents to a plurality of servers, the proxy server 125 receives the first received and transferred to the browser 101 in order to avoid sending duplicate information. All responses from the server will be discarded.

  Further, the URL of the mirror server corresponding to a certain web server may be changed or deleted in the future. For this reason, the created mirror server URL database can be deleted after a certain period.

  According to the present embodiment, since a server with a fast response is selected for each access, even when the response speed of the server decreases due to a sudden increase in traffic or a failure, download from a server with a fast response is always performed. Can be realized.

  Although the present invention has been described with reference to the preferred embodiments, the present invention is not necessarily limited to the above embodiments, and various modifications can be made within the scope of the technical idea.

It is a figure which shows the whole structure of the web content delivery system by the Example of this invention. It is a figure which shows operation | movement of the web content delivery program by the Example of this invention. It is a figure which shows operation | movement of the web content delivery program by the Example of this invention. It is a flowchart for demonstrating operation | movement of the proxy server by 1st Example of this invention. It is a figure which shows the whole structure of the conventional web content delivery system. It is a figure for demonstrating the problem in the conventional web content delivery system.

Explanation of symbols

101: Browser 108: Web content 109, 110, 111: File 112, 113: Route 114, 115, 116: Route 117, 118, 119: Route 120: Internet network 122: Web server 123, 124: Mirror server 125: Proxy Server 126: Mirror server URL database 127, 128: Content distribution program

Claims (14)

A web content distribution system comprising a web server having web content and a mirror server having web content of the same content as the web server, wherein the web content is accessed from a browser via a proxy server,
When the first file in the web content is requested from the browser via the proxy server to the web server,
The web server sends the mirror server URL to the proxy server along with the requested file;
When another file of the web content is requested from the browser,
The proxy server selects a server that can respond from the mirror server indicated by the web server and URL, and receives the file.   2. The proxy server according to claim 1, wherein the proxy server selects a server that responds within a predetermined time from the web server and the mirror server indicated by a URL, and transmits the file request. Web content distribution system.   3. The web content distribution system according to claim 1, wherein the proxy server selects the server every time another file of the web content is requested from the browser. 4.   The web content distribution system according to any one of claims 1 to 3, wherein the web server writes a URL of the mirror server in an HTTP header of a requested file and sends it back.   The proxy server deletes the description of the mirror server URL from the HTTP header of the file, transfers the file to the browser, and also describes the mirror server URL corresponding to the URL of the web server. 5. The web content distribution system according to claim 4, wherein a URL database is created. A web server having a web content and a mirror server having a web content having the same content as the web server, and the web server and the proxy of a web content distribution system for accessing the web content from a browser via the proxy server A web content distribution program that operates on a server and realizes load balancing in the web content distribution,
The web content delivery program of the web server is
When the first file in the web content is requested from the browser via the proxy server from the browser, a function of transmitting the URL of the mirror server together with the requested file to the proxy server is executed. ,
The proxy server web content distribution program is:
When another file of the web content is requested by the browser, a function of selecting a server that can respond from the web server and the mirror server indicated in the URL and receiving the file is executed. Web content distribution program.   The proxy server web content distribution program executes a function of selecting a server that responds within a predetermined time from the web server and the mirror server indicated in the URL and transmitting the file request. The web content distribution program according to claim 6, wherein the program is a web content distribution program.   The web content distribution program of the proxy server executes a function of selecting the server each time another file of the web content is requested from the browser. The web content distribution program described.   9. The web content distribution program of the web server executes a function of entering and returning a URL of the mirror server in an HTTP header of a requested file. Web content distribution program described in 1.   The proxy server web content distribution program deletes the description of the URL of the mirror server from the HTTP header of the file and transfers the file to the browser. The URL of the mirror server corresponds to the URL of the web server. 10. The web content distribution program according to claim 9, wherein a function of creating a mirror server URL database describing the URL is executed. A proxy server of a web content distribution system comprising a web server having web content and a mirror server having web content having the same content as the web server, wherein the web content is accessed from a browser via the proxy server,
When the first file in the web content is requested from the browser, the URL of the mirror server is received together with the requested file from the web server;
When another file of the web content is requested from the browser, the proxy server selects a server that can respond from the web server and the mirror server indicated in the URL, and receives the file.   12. The proxy server according to claim 11, wherein a request for the file is transmitted by selecting a server that has responded within a predetermined time from the web server and the mirror server indicated by the URL.   13. The proxy server according to claim 11, wherein the server is selected every time another file of the web content is requested from the browser.   When the URL of the mirror server is written in the HTTP header of the file and returned from the web server, the URL of the mirror server is deleted from the HTTP header of the file and the file is transferred to the browser. The proxy server according to any one of claims 11 to 13, wherein a mirror server URL database in which a URL of the mirror server is described in correspondence with a URL of the web server is created.

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