JP4627789B2 - Information processing apparatus, information processing method, and program - Google Patents

Description

  The present invention relates to an information processing apparatus, an information processing method, and an apparatus readable for realizing the same, capable of developing an application in an environment where a plurality of virtual machines operate in the same manner as an environment where a single virtual machine operates. Related to various programs.

  In order to provide an optimal office environment for each customer, a system that can be customized for each customer by adding an application is being studied. The added applications include those developed by third vendors, but the addition should not impair the basic functions of the system. Here, the third vendor refers to a vendor that provides hardware or software that provides a new function by being incorporated into an existing environment, such as hardware or an OS.

  When developing and adding an application, if a request for the application is received, the request must be appropriately distributed to the resource that executes the application.

  There is a technology called capacity on demand that provides optimum processing performance by controlling the CPU and memory incorporated in the server according to the access status and processing load. In order to facilitate this capacity on demand, a method and a system for remotely and dynamically configuring a Web server have been proposed (see, for example, Patent Document 1).

  In this method and system, a server group 1 that processes requests from clients, a server group 3 that provides resources, and a server that determines whether the performance of the server group 1 and the performance of the server group 3 have reached a threshold. The server is added to or deleted from the server group according to the performance status of the server group 1 or the server group 3. Thereby, a robust and flexible Web server is realized. In this method and system, one server appropriately distributes processing to other servers, and dynamic addition of resources is possible.

  In addition, an image forming apparatus that can provide a Web service without requiring a driver for a personal computer (PC) and without depending on the model or OS of the PC has been proposed (for example, Patent Document 2). reference). This image forming apparatus includes means for providing a Web service for each of a plurality of hardware resources, and a Web service function corresponding to information for specifying a Web service included in a message described according to a message exchange protocol in a request To identify the Web service, distribute it to the Web service, and provide a response. This apparatus analyzes the request and distributes the request to an appropriate processing unit.

  In a process-based operating system (OS) such as UNIX (registered trademark), when building a system that can be customized for each customer by adding the above-mentioned application, in order to improve the robustness of the system, the process is performed with an appropriate granularity. Is generally divided. Here, robustness means that the program is resistant to errors and exceptions and does not easily run away.

  When the Java (registered trademark) language is used as an application development language, a plurality of applications are operated on a single process, that is, a single virtual machine. In this case, dividing the process with fine granularity is not practical. However, by configuring two virtual machines to run at least one application that realizes basic functions on one virtual machine and run an application developed by a third vendor on the other virtual machine, The robustness of the system can be improved.

JP 2005-539298 A JP 2007-135238 A

  The technique of the above-mentioned patent document 1 is server resource optimization and cannot be applied to an apparatus in which a plurality of virtual machines operate on the premise that each server is hardware independent.

  The technique of the above-mentioned patent document 2 provides a Web service without depending on the user's environment, and appropriately requests requests to applications operating on each virtual machine in an environment where a plurality of virtual machines operate. It is not something to distribute.

  When application development is performed in an environment in which a plurality of virtual machines operate, if one HTTP server attempts to manage all virtual machine Web applications, inter-process communication is required between the HTTP server and the Web application. . Adding inter-process communication processing to each Web application places a heavy burden on application development and makes the development difficult. On the other hand, in an environment where a single virtual machine operates, since one HTTP server and a plurality of applications operate on a single process, inter-process communication is unnecessary, and such a problem does not occur.

  Therefore, application development can be easily performed without adding inter-process communication processing to the Web application. Even if the developed application is added to an environment in which multiple virtual machines operate, the request received from the client is appropriately handled. In addition, it is desired to provide an apparatus that can be distributed to applications running on each virtual machine.

In view of the above problems, the present invention is an information processing apparatus in which three or more virtual machines operate, and each of the virtual machines performs processing in the application for each of the applications operating on its own virtual machine. The first management information in which the target file name and file extension are registered is retained, and an application corresponding to the file name and file extension included in the request received from the client is stored on the basis of the first management information. An application management unit that determines an application that processes a request, and one master virtual machine that receives a request from the client among the plurality of virtual machines identifies each worker virtual machine other than the master virtual machine Identification information on the worker virtual machine A request in which each of the operating applications holds the second management information associated with at least the file extension to be processed, and the application operating on the worker virtual machine includes the file extension to be processed A request transfer unit that transfers the request to a worker virtual machine having identification information corresponding to the file extension included in the request, based on the second management information, When a plurality of pieces of identification information corresponding to file identifiers included in the request are registered in the second management information, the request transfer unit of the master virtual machine has a predetermined priority order from the plurality of pieces of identification information. The request addressed to the worker virtual machine of one identification information selected based on The application management unit of the worker virtual machine transfers the application corresponding to the file name and file extension included in the request transferred from the master virtual machine based on the first management information. If it is determined whether or not it exists in the virtual machine, and if it is determined to exist, the result of processing the request using this application is sent to the client via the master virtual machine, If it is determined that the application does not exist, the application checks whether there is a corresponding application in another worker virtual machine other than its own worker virtual machine, and sends the result of the investigation to the master virtual machine. The request transfer unit of the virtual machine transfers the request that has transferred the request. Identification of the next priority selected from the plurality of identification information when the investigation result indicating that an application corresponding to another worker virtual machine other than the worker virtual machine exists is received from the car virtual machine When the request is forwarded to the information worker virtual machine and the investigation result indicating that there is no application corresponding to any worker virtual machine is received, the request is sent to the worker virtual machine of the next priority. A response indicating that there is no corresponding application is not transmitted to the client .

The present invention is also an information processing method executed by an information processing apparatus on which three or more virtual machines operate, wherein each of the virtual machines has an application for each of the applications operating on its own virtual machine. The first management information in which the file name and the file extension to be processed in is registered, and the master virtual machine that is one of the plurality of virtual machines is further connected to each worker virtual machine that is another virtual machine. Holding second management information in which at least the identification information for identifying the machine and the file extension to be processed by each of the applications running on the worker virtual machine are associated, A request including a file extension to be processed by an application running on the worker virtual machine. A first determination step for determining whether or not a plurality of identification information corresponding to the file extension included in the request is registered in the second management information when the client receives a request from the client; When it is determined in the determination step that only one piece of identification information is registered, the request is transferred to the worker virtual machine of this identification information, and when it is determined that a plurality of pieces of identification information are registered. A transfer step of forwarding the request to the worker virtual machine of one identification information selected from among the plurality of identification information based on a predetermined priority, and in the worker virtual machine, based on the first management information , An application corresponding to the file name and file extension included in the request transferred from the master virtual machine. In the second determination step for determining whether or not the application exists in its own worker virtual machine, and in the second determination step, this application is used when it is determined that the corresponding application exists. The result of processing the request is sent to the client via the master virtual machine, and if it is determined that the corresponding application does not exist, it is handled in another worker virtual machine other than its own worker virtual machine. A first transmission step of transmitting whether or not there is an application to be transmitted, and transmitting the result of the investigation to the master virtual machine; and in the master virtual machine, from the worker virtual machine that has transferred the request, App for other worker virtual machines other than machines The request is forwarded to the worker virtual machine of the next priority identification information selected from the plurality of identification information, and to any worker virtual machine When the investigation result indicating that there is no corresponding application is received, the request is not transferred to the worker virtual machine having the next priority, and a response indicating that the corresponding application does not exist is transmitted to the client. A second transmission step.

Further, the present invention is a program for processing a request from a client that can be read by an information processing apparatus in which three or more virtual machines operate, and each of the virtual machines operates on its own virtual machine For each of the applications, the first management information in which the file name and the file extension to be processed by the application are registered, and the master virtual machine that is one of the plurality of virtual machines further includes other Second management information in which identification information for identifying each worker virtual machine that is a virtual machine of the virtual machine is associated with at least a file extension to be processed by each of the applications running on the worker virtual machine In the master virtual machine, an application running on the worker virtual machine Whether a plurality of identification information corresponding to the file extension included in the request is registered in the second management information when a request including a file extension to be processed is received from the client. When it is determined in the first determination step that determines whether or not only one piece of identification information is registered in the first determination step, the request is forwarded to the worker virtual machine of this identification information, A transfer step of transferring the request to the worker virtual machine of one identification information selected from among the plurality of identification information based on a predetermined priority when it is determined that the identification information is registered. The worker virtual machine is included in the request transferred from the master virtual machine based on the first management information. In the second determination step for determining whether or not an application corresponding to the file name and the file extension exists in the worker virtual machine, and in the second determination step, it is determined that the corresponding application exists. If the result of processing the request using this application is sent to the client via the master virtual machine and it is determined that the corresponding application does not exist, A first transmission step of investigating whether or not a corresponding application exists in another worker virtual machine and transmitting the investigation result to the master virtual machine, and forwarding the request in the master virtual machine From the worker virtual machine, the worker temporary When the investigation result indicating that an application corresponding to another worker virtual machine other than the machine exists is received, the worker information of the next priority identification information selected from the plurality of identification information is addressed to the worker virtual machine. When the request is transferred and the investigation result indicating that there is no application corresponding to any worker virtual machine is received, the request is not transferred to the worker virtual machine of the next priority, and the corresponding application is Causing the information processing apparatus to execute a second transmission step of transmitting a response to the effect that it does not exist to the client.

  According to the present invention, a virtual machine that should process this request is determined from address information, management information, and identification information included in the request received from the client, and the request is transferred to the virtual machine. As a result, even if the developed application is added to an environment where a plurality of virtual machines operate, a request received from a client can be appropriately distributed to applications operating on each virtual machine.

  FIG. 1 is a diagram exemplifying a network device configuration including a server device which is an embodiment of an information processing apparatus of the present invention. In FIG. 1, a server device 10 and a client device 11 are connected to a network 12 and can communicate with each other.

  The client device 11 implements a web browser as software, and the server device 10 implements a web server as software. The Web server receives a request issued from the Web browser via the network 12 such as the Internet, processes the request by the Web application, and transmits the processing result to the Web browser.

  When the Web browser obtains information corresponding to the URL specified by the user, the Web browser sends the URL as a request to the Web server. The Web server receives the URL, reads a file for displaying the Web page from a path name included in the URL, that is, a file name or a directory name, and returns the file as a processing result.

  Communication between the Web browser and the Web server is performed using a communication protocol such as HTTP. A web browser that performs communication using this HTTP is called an HTTP client, and a web server is called an HTTP server. Hereinafter, the Web browser is referred to as an HTTP client, and the Web server is referred to as an HTTP server. In order to receive a request from an HTTP client, the HTTP server opens an external port serving as a connection port for connecting each other. This external port is generally port number 80 and there is only one. For this reason, communication between the HTTP server and the HTTP client is performed only through this one external port.

  The server device 10 and the client device 11 include a CPU for operating an HTTP server and an HTTP client, a memory for storing a program to be executed by the CPU, and a communication interface such as a network board and a network card for performing communication. Or a multifunction machine. In FIG. 1, only one PC is shown as the client device 11, but two or more client devices 11 are connected to the network 12, and a request can be transmitted from each client device 11.

  Next, the configuration of modules mounted on the server apparatus 10 shown in FIG. 1 will be described in detail with reference to FIG. The server device 10 can include a plurality of virtual machines, but only three virtual machines are shown in FIG. Here, the virtual machine is software that executes a virtualized computer after resources such as a CPU and a memory of the computer are virtualized by being flexibly divided or integrated regardless of a physical configuration. Further, the virtual machine can be a Java (registered trademark) virtual machine whose programming language is Java (registered trademark). Note that this Java (registered trademark) virtual machine exists as an execution file in each OS, and after execution, the class file is read and a method in the class is called and executed.

  The server apparatus 10 can start up three virtual machines at the same time. Therefore, three different OSs can be executed at the same time, and applications can be operated on the OSs. In FIG. 2, three virtual machines 20, 30, and 40 each include one HTTP server 21, 31, and 41, the virtual machine 20 includes three Web applications 22a to 22c, and the virtual machine 30 includes two Web applications 32a and 32b. The virtual machine 40 includes two Web applications 42a and 42b. Each HTTP server and each Web application can be operated on each virtual machine. Note that the HTTP servers 21, 31, and 41 are the same module. On the other hand, the Web applications 22a to 22c, 32a, 32b, 42a, and 42b are different modules.

  The three virtual machines 20, 30 and 40 are classified into one master virtual machine 20 and other worker virtual machines 30 and 40. The master virtual machine 20 receives a request from the outside of the server apparatus 10 using an external port, and address information such as a URL included in the request is a Web application of the worker virtual machine 30 or a Web application of the worker virtual machine 40. If so, distribute the request processing to those virtual machines. The worker virtual machines 30 and 40 receive a request from the master virtual machine 20 using an internal port that is used only inside the server apparatus 10, and execute processing by a Web application indicated by the URL included in the request. The processing result is returned to the master virtual machine 20. Thereafter, the master virtual machine 20 transmits the processing result using the external port to the client apparatus 11 that is the transmission source of the request.

  In Java (registered trademark), a Web application is created in the form of a servlet or JSP (registered trademark), and the Web application is executed using an application server corresponding to the HTTP server described above. Here, the servlet is a Java (registered trademark) program to be executed on the server, and the JSP (registered trademark) is a file in which the Java (registered trademark) program is embedded in HTML. As an application server, Tomcat (registered trademark) can be used as an example, and Struts (registered trademark) can be used as a web application framework. This framework is a library that provides a program framework and provides basic mechanisms such as data input / output, error handling, and screen transition required for applications. Web applications can be created using J2SE as a basic tool for developing Java (registered trademark) applications. The created web application is stored in a database.

  A specific process using the created Web application will be described. Tomcat (registered trademark), which is an application server, is run on J2SE, which is a Java (registered trademark) virtual machine, the Web application is read, and the Web It is possible to execute a servlet and JSP (registered trademark) constituting an application, process a request, and return a processing result to an HTTP client. Therefore, this J2SE can be used as a virtual machine, and Tomcat (registered trademark) can be used as an HTTP server.

  As described above, since an HTTP server exists on each virtual machine, it is possible to develop a Web application independently for each virtual machine. In addition, even in an environment where a plurality of virtual machines operate, similarly to an environment where a single virtual machine operates, a web application can be easily developed without adding inter-process communication processing. Thereby, the load at the time of development of a Web application can be reduced, and Web application development efficiency can be improved.

  With reference to FIG. 3, the configuration of an HTTP server operating on the master virtual machine 20 will be described in detail. The HTTP server receives a request issued from the HTTP client 100 of the client device 11 via the network 12, assembles a request reception unit 23 that interprets the request, a processing result by the Web application as a response, A request transmission unit 24 that transmits a request to the HTTP client of the client device 11, an application management unit 25 that holds a plurality of Web applications in association with URLs, and another HTTP server to distribute processing. And a request transfer unit 26.

  Further, in FIG. 3, a request storage unit 27 that temporarily stores a request in a memory and retrieves the request in response to a request, and a virtual machine control unit that stores priority information related to a priority order for transferring the request to a plurality of worker HTTP servers 28.

  Here, the HTTP server 21 operating on the master virtual machine 20 is a master HTTP server, and the HTTP servers 31 and 41 operating on the worker virtual machines 30 and 40 are worker HTTP servers. These HTTP servers 21, 31, and 41 are the same module, but behave as either a master HTTP server or a worker HTTP server depending on whether the virtual machine in which they exist is a master or a worker. For example, the master virtual machine 20 is a virtual machine that implements a Web application for realizing basic functions, and the worker virtual machines 30 and 40 are Web applications created by the administrator of the server device 10 to add functions. It can be a virtual machine to be mounted or a virtual machine to be mounted with a Web application created by a third vendor.

  The master HTTP server 21 opens an external port in order to communicate with the client device 11 that is an external device of the server device 10 via the network 12. As a result, it is possible to access the external port from the outside of the server device 10, for example, the client device 11.

  On the other hand, the worker HTTP servers 31 and 41 open an internal port in order to perform communication inside the server device 10. This internal port is for enabling communication between the master HTTP server 21 and the worker HTTP servers 31 and 41, and can be accessed using a loopback which is an internal transmission / reception function. Since the internal port is used only for communication between HTTP servers inside the server device 10, the worker HTTP servers 31 and 41 cannot be accessed from outside the server device 10. Since duplication of port numbers is not permitted, different port numbers are assigned to external ports and internal ports. Since the external port is generally port number 80, the internal port can be assigned other port numbers 8080 and 8081, for example.

  The master HTTP server 21 and the worker HTTP servers 31 and 41 know whether they are masters or workers. However, none of the web applications 22a to 22c, 32a, 32b, 42a, and 42b running on the master virtual machine 20 and the worker virtual machines 30 and 40 knows whether they are a master or a worker. These are managed by HTTP servers 21, 31 and 41 that know whether they are masters or workers. For this reason, a web application can be developed without distinguishing whether it is a master or a worker.

  With reference to FIG. 4, processing when a Web application on the master virtual machine 20 is registered in the master HTTP server 21 will be described. When registering a Web application, the Web application existing in the master virtual machine 20 registers a URL to the HTTP server 21 existing in the master virtual machine 20. Specifically, when the Web application 22a requests the HTTP server 21 to register URL of “url1” (step S11), the application management unit 25 included in the HTTP server 21 sets the URL as the Web application 22a. The data is stored in association with each other (step S12). That is, the URL is stored in the correspondence table or the like in association with the application name or the like for identifying the Web application 22a. Further, after storing the URL, the application management unit 25 returns a response indicating that the storage is completed to the Web application 22a (step S13).

  On the other hand, after the URL is registered, when a “GET / url1 HTTP / 1.1” request is transmitted from the HTTP client 100 of the client device 11 (step S14), the request receiving unit 23 of the HTTP server 21 receives the request and receives the request. Is interpreted (step S15). Here, it is interpreted as “obtain the file at url1 with the transfer standard HTTP / 1.1”. Then, the request reception unit 23 delivers the request to the application management unit 25 in order to determine which Web application the request is distributed to (step S16).

  The application management unit 25 refers to the correspondence table and searches for a Web application corresponding to the URL included in the request received from the request reception unit 23 (step S17). Here, when a corresponding Web application is found, the application management unit 25 requests the corresponding Web application (Web application 22a) to perform processing (step S18). The Web application 22a executes the requested processing (step S19), and transmits the processing result as a response to the application management unit 25 (step S20).

  Next, the application management unit 25 transmits the response received from the Web application to the response transmission unit 24 (step S21), and the response transmission unit 24 transmits the response to the HTTP client 100 (step S22). In FIG. 4, a message “HTTP / 1.1 200 OK” indicating that the message has been found is transmitted. “HTTP / 1.1” is a transfer standard, and “200” is a status code indicating success. Along with these messages, a file for displaying the Web page at the address is sent to the HTTP client 100, and the Web page is displayed on the screen of the client device 11. Although the registration of the Web application 22a has been described with reference to FIG. 4, it is assumed that the same processing is performed for the Web applications 22b and 22c.

  In step S17, when the Web application corresponding to the URL is not found, an error message indicating that the resource is not found is transmitted as a response. Hereinafter, with reference to FIG. 5, processing when a Web application corresponding to the URL is not found will be described. In addition, about the process of step S31-S36 in FIG. 5, since it is the same as that of the process of step S11-S16 mentioned above, description is abbreviate | omitted.

  In step S <b> 37, the application management unit 25 refers to the correspondence table and searches for a Web application corresponding to the URL “foo” passed from the request reception unit 23. If it is determined that the corresponding Web application is not found, the application management unit 25 creates an error message “404 Not Found” indicating that the resource is not found as shown in FIG. A response is transmitted to the response transmitter 24 (step S38). The response transmission unit 24 transmits this error message to the HTTP client 100 (step S39). In the HTTP protocol, “404” is a status code indicating that it was not found. Thereby, the user who operates the client apparatus 11 can be made to recognize that a resource is not found.

  Next, a case where a Web application on the worker virtual machine 30 is registered in the worker HTTP server 31 will be described with reference to FIG. The Web application 32 a existing in the worker virtual machine 30 registers a URL with respect to the HTTP server 31 existing in the same worker virtual machine 30. Specifically, when the Web application 32a performs URL registration of “url2” to the HTTP server 31 (step S41), the application management unit 35 associates this URL with the Web application 32a and stores it in a correspondence table or the like. Store (step S42).

  After registering the URL, the HTTP server 31 determines the type of virtual machine in which the HTTP server 31 itself exists, that is, whether it is a master or a worker. In this case, it is determined that the worker is a worker, and a request for transferring the request to the master HTTP server 21 is made (step S43). The worker HTTP server 31 transmits information including the registered URL, the port name or number of the external port, and the port name or port number of the internal port to the master HTTP server 21 as a distribution request registration. Shall be. This can be achieved by using a remote procedure call (RPC) that defines a procedure for executing processing on different machines. As described above, since the URL of the Web application can be dynamically registered in the master HTTP server 21 by using the RPC, even if the Web application is added to the worker HTTP servers 31 and 41, the master HTTP server 21 can be added. No need to make corrections. Thereby, the load at the time of web application development can be reduced, and web application development efficiency can be improved.

  When the request transfer unit 26 included in the master HTTP server 21 receives the URL, the port name or number of the external port, and the port name or port number of the internal port from the worker HTTP server 31, the application management unit 25 stores these pieces of information. (Step S44). When the application management unit 25 associates each piece of information received from the request transfer unit 26 and stores the information in the correspondence table or the like (step S45), the application management unit 25 sends a response notifying the completion of storage via the request transfer unit 26 to the worker virtual machine. 30 to the application management unit 35 (steps S46 and S47).

  On the other hand, when receiving a response notifying that the storage has been completed from the request transfer unit 26, the application management unit 35 returns this response to the Web application 32a (step S48), thereby completing the registration process. Although the registration of the Web application 32a has been described with reference to FIG. 6, it is assumed that the same processing is performed for the Web application 32b. Further, although the worker virtual machine 30 has been described with reference to FIG. 6, it is assumed that the same processing is performed even in the case of the worker virtual machine 40.

  On the other hand, when “GET / url2 HTTP / 1.1” is transmitted as a request from the HTTP client 100 of the client device 11 after registration of the URL (step S49), the request receiving unit 23 of the HTTP server 21 receives this, The request is interpreted (step S50). In this case, it is interpreted as “obtain the file at url2 with the transfer standard HTTP / 1.1”. When the request reception unit 23 passes the received request to the application management unit 25 (step S51), the application management unit 25 refers to the correspondence table and searches for the Web application 32a corresponding to the URL included in the request. (Step S52).

  If the URL “url2” included in the request corresponds to the Web application 32a, the Web application 32a is an application that operates on the worker virtual machine 30, and thus cannot be found on the master virtual machine 20. Therefore, the application management unit 25 requests the request transfer unit 26 to transfer the request to transfer to the worker HTTP server 31 operating on the worker virtual machine 30 (step S53). Upon receiving the request transfer request, the request transfer unit 26 transfers the request to the port number of the internal port of the worker virtual machine 30 that is the transfer destination (step S54).

  As described above, the master HTTP server 21 transfers the request to the worker HTTP servers 31 and 41 using HTTP. In this case, since the worker HTTP servers 31 and 41 are the same as when receiving a request from a general Web browser, it is not necessary to modify the request processing of the worker HTTP servers 31 and 41. Further, the master HTTP server 21 uses an external port to communicate with the outside of the information processing apparatus, and the worker HTTP servers 31 and 41 identify themselves with the internal port to communicate with the master HTTP server 21. A request is received using a loopback address, and a processing result for the request is transmitted. As a result, direct access to the worker HTTP servers 31 and 41 from the outside of the server apparatus 10 can be prevented, so that only the master HTTP server 21 needs to be considered in terms of security, and the entire apparatus The burden of maintenance and management can be reduced.

  The request transmitted from the request transfer unit 26 is interpreted by the request reception unit 33 of the worker HTTP server 31 operating on the worker virtual machine 30 (step S55), and then passed to the application management unit 35 (step S56). ). The application management unit 35 refers to the correspondence table and searches for a Web application corresponding to the URL included in the request received from the request reception unit 33 (step S57). In this case, since the web application 32a corresponding to the URL is included in the web applications 32a and 32b operating on the worker virtual machine 30, the application management unit 35 requests the web application 32a to perform processing (step) S58). The Web application 32a executes the requested processing (step S59), and transmits the processing result as a response to the application management unit 35 (step S60). When the application management unit 35 transmits the response received from the Web application 32a to the response transmission unit 34 (step S61), the response transmission unit 34 transmits the response to the request transfer unit 26 of the master virtual machine 20 (step S62). ).

  On the other hand, when receiving a response from the response transmission unit 34, the request transfer unit 26 transmits this response to the application management unit 25 (step S63). Subsequently, when the application management unit 25 transmits the response received from the request transfer unit 26 to the response transmission unit 24 (step S64), the response transmission unit 24 transmits the response to the HTTP client 100 (step S65).

  As described above, the master HTTP server 21 receives the URL of the Web application included in each worker HTTP server from the HTTP client 100 using the correspondence table in which the information about the external / internal port of the worker HTTP server is associated with each other. The virtual machine corresponding to the URL (address information) included in the request is determined, and the request is transferred to the virtual machine.

  Next, an operation when the Web application of each worker virtual machine is associated with the same URL will be described. First, the background that the same URL is set in the Web application of each worker virtual machine will be described.

  When creating a Web application using Java (registered trademark), a framework such as Struts (registered trademark) is generally used as described above. There are various types of frameworks such as commercial or open source, but depending on the specifications, the web application is based on the extension part of the file specified by the URL regardless of the directory specifying part included in the URL. There is something that does the processing. When a framework with such a specification is used, if each Web application is specified to perform processing for the same extension, each Web application is associated with the same URL, that is, a file extension. become. Hereinafter, processing when a plurality of Web applications are associated with the same URL will be described.

  With reference to FIG. 7, the process in the case of registering the Web applications 32a and 42a in the worker HTTP servers 31 and 41 will be described. In FIG. 7, the Web applications 32a and 42a will be described. However, the same processing is also performed for the Web applications 32b and 42b. In FIG. 7, it is assumed that each of the Web applications included in the worker virtual machine 30 and the worker virtual machine 40 is associated with the same URL, that is, the same file extension.

  First, when the Web application 32a registers a URL with the HTTP server 31 (step S71), as described above, the application management unit 35 associates the URL with the application 32a and stores them in a correspondence table or the like ( Step S72). Although FIG. 7 shows an example in which the URL for registration is “/*.cgi” (an asterisk is an arbitrary character string), it is not limited to this.

  After registering the URL, the HTTP server 31 determines the type of virtual machine in which the HTTP server 31 itself exists, that is, whether it is a master or a worker. In this case, it is determined as a worker, and a request is made to have the request transferred to the master HTTP server 21 (step S73).

  When the Web application 42a registers the same URL (/*.cgi) as the Web application 32a in the HTTP server 41 (step S74), the application management unit 45, as with the Web application 32a, The web application 42a is associated and stored in a correspondence table or the like (step S75). After registering the URL, the HTTP server 41 determines the type of virtual machine on which the HTTP server 41 itself exists, that is, whether it is a master or a worker. In this case, it is determined that the worker is a worker, and a request for transferring the request to the master HTTP server 21 is made (step S76).

  On the other hand, when the request transfer unit 26 provided in the master HTTP server 21 receives the URL, the port name or number of the external port, and the port name or port number of the internal port from the worker HTTP servers 31 and 41, these information are stored. The data is passed to the application management unit 25 (steps S77 and S78). The application management unit 25 associates each information about the worker HTTP servers 31 and 41 received from the request transfer unit 26 and stores them in the correspondence table or the like (steps S79 and S80), and a response notifying that the storage is completed Is transmitted to the request transfer unit 26 (steps S81 and S82). Upon receiving a response from the application management unit 25, the request transfer unit 26 transmits the response to the application management units 35 and 45 of the worker virtual machines 30 and 40, respectively (steps S83 and S84). On the other hand, when each of the application management units 35 and 45 receives a response notifying that the storage is completed from the request transfer unit 26, the response is returned to the Web applications 32a and 42a, respectively (steps S85 and S86). The registration process is complete.

  Note that the master HTTP server 21 receives and stores URLs from the worker HTTP servers 31 and 41 in order to distribute requests, but in this case, the URL is the same. However, since the port number of the internal port opened by the worker HTTP server 31 is 8080 and the port number of the internal port opened by the worker HTTP server 41 is different from 8081, it can be determined by the port number of this internal port. The same URL can be registered for these applications. Thereby, the Web application developer of each worker HTTP server 31 or 41 does not need to be aware of whether the URL overlaps with a Web application having another worker HTTP server when developing the application. Therefore, since it is not necessary to adjust the URL of the Web application between the worker HTTP servers, the load during application development can be reduced and the application development efficiency can be improved.

  On the other hand, when a request “GET /url/app2.cgi HTTP / 1.1” is transmitted from the HTTP client 100 of the client apparatus 11 after URL registration (step S87), the request receiving unit 23 of the HTTP server 21 transmits this request. The request is received and the request is interpreted (step S88). In this case, it is interpreted that “a file named app2.cgi in the directory of the directory name url is acquired by the transfer standard HTTP / 1.1”.

  The request reception unit 23 passes the request received from the HTTP client 100 to the application management unit 25 (step S89). When receiving a request from the request reception unit 23, the application management unit 25 refers to the correspondence table and searches for a Web application corresponding to the URL included in the request (step S90). In this case, since the Web application corresponding to the URL is an application that operates on the worker virtual machine 30 or the worker virtual machine 40, it cannot be found on the master virtual machine 20. Therefore, the application management unit 25 requests the request transfer unit 26 to transfer the request to the worker HTTP server 31 or the worker HTTP server 41 operating on the worker virtual machine 30 (step S91).

  Here, since the URL registered by the two Web applications 32a and 42a is the same, the request transfer unit 26 transfers the request to one of the two worker virtual machines 30 and 40 (step S92). In this case, since the request may be retransmitted to the remaining virtual machines later, the request transfer unit 26 transmits the accepted request to the request storage unit 27 (step S93), thereby requesting the request storage unit 27 to make a request. Is temporarily saved.

  In step S92, the request transfer unit 26, for example, the transfer order to each worker virtual machine (Web application) registered in advance in the application management unit 25 by the Web application, or each worker virtual machine registered in advance. The request is transferred according to priority information indicating the priority of (Web application). When the Web application 32a operating on the worker virtual machine 30 is registered or has a higher priority, the request transfer unit 26 transfers the request to the port number of the internal port opened by the worker virtual machine 30.

  When receiving a request transferred from the master virtual machine 20, the request receiving unit 33 of the worker HTTP server 31 operating on the worker virtual machine 30 interprets the request in the same manner as the request receiving unit 23 (step S94). Then, the request reception unit 33 delivers the request to the application management unit 35 in order to determine which Web application the request is distributed to (step S95).

  The application management unit 35 refers to the correspondence table and searches for a web application corresponding to the URL included in the request received from the request reception unit 33 (step S96). Here, assuming that the requested file “app2.cgi” corresponds to the Web application 32a, the application management unit 35 includes the URL in the Web applications 32a and 32b operating on the worker virtual machine 30. It is determined that the corresponding web application 32a is included, and the web application 32a is requested to perform processing (step S97). The Web application 32a executes the requested processing (step S98), and transmits the processing result as a response to the application management unit 35 together with the status code “200” indicating success (step S99). When receiving a response from the Web application 32a, the application management unit 35 transmits the response to the response transmission unit 34 (step S100), and the response transmission unit 34 sends the response transmitted from the application management unit 35 to the request of the master virtual machine 20. It transmits to the transfer part 26 (step S101).

  On the other hand, when receiving a response to the request transferred in step S92, the request transfer unit 26 determines whether or not the status code included in the response is a special value set in advance, for example, “900” (step S102). If the status code is not a special value, the request transfer unit 26 transmits a response to the response transmission unit 24 via the application management unit 25 (steps S103 and S104). Next, the response transmission unit 24 transmits the response received from the application management unit 25 to the HTTP client 100 (step S105).

  The special value may be any value as long as it is not set as a status code in the HTTP protocol. For example, it may be “900” as described above. It is assumed that the status code “900” is set in advance to be transmitted when a corresponding Web application is not found in the worker virtual machine to which the request has been transferred.

  The above priority is preset by the user as priority information, and is held by the virtual machine control unit 28 included in the master HTTP server 21 operating on the master virtual machine 20. For example, the priority 1 can be set for the worker virtual machine 30 and the priority 2 can be set for the worker virtual machine 40. This priority information is set when the server device 10 is activated, and can be dynamically changed during execution.

  The processing using this priority information will be described. The request transfer unit 26 of the master HTTP server 21 acquires the priority information of the master virtual machine 20 from the virtual machine control unit 28, and the virtual machine that has not transferred the request. Select the highest priority among them and transfer the request. After that, when a status code having a special value set in advance, “900”, is received, the virtual machine having the next priority is selected and the request is transferred. If a special value status code is not received, the virtual machine with the next priority is not selected, and the process is executed by the Web application corresponding to the URL that operates on the virtual machine with the highest priority. The result is transmitted to the request transfer unit 26.

  In the above, it has been explained that there is a possibility of resending a request. However, there is an upper limit to the high-speed memory (RAM) that can be used in the server device 10, and there are cases where all requests cannot be held in this RAM. Therefore, an upper limit is set for the size held in the RAM, and when the request size exceeds the upper limit, the request storage unit 27 can temporarily store it in another storage medium such as an HDD. Thereby, even when there is a restriction on the memory size of the RAM, the request can be retransmitted by using an alternative alternative storage medium.

  When the URL registered in the application management unit 25 is the same and there is a corresponding Web application on the worker virtual machine 30 to which the request has been distributed first, the processing shown in FIG. 7 is performed. However, when there is no corresponding Web application on the worker virtual machine 30 that has been distributed first, the same processing as in FIG. 7 is not performed. Therefore, the flow of processing in this case will be described with reference to FIG.

  First, when a request “GET /url/app3.cgi HTTP / 1.1” is transmitted from the HTTP client 100 of the client device 11 (step S111), the request receiving unit 23 of the HTTP server 21 receives the request and receives the request. Is interpreted (step S112). In this case, it is interpreted that “a file named app3.cgi in the directory of the directory name url is acquired by the transfer standard HTTP / 1.1”. The requested file “app3.cgi” designates the Web application 42a.

  The request receiving unit 23 interprets the request and then passes the received request to the application management unit 25 (step S113). When receiving a request from the request reception unit 23, the application management unit 25 refers to the correspondence table and searches for a Web application corresponding to the URL included in the request (step S114). In this case, since the Web application corresponding to the URL is an application that operates on the worker virtual machine 30 or the worker virtual machine 40, it cannot be found on the master virtual machine 20. Therefore, the application management unit 25 requests the request transfer unit 26 to transfer the request to the worker HTTP server 31 or the worker HTTP server 41 operating on the worker virtual machine 30 (step S115).

  When receiving the transfer request from the application management unit 25, the request transfer unit 26 transfers the request to the port number of the internal port opened by the worker virtual machine 30 or 40 (step S116). Also in this case, since the URL registered in the application management unit 25 is the same, the request transfer unit 26 transfers the request to one of the two worker virtual machines 30 and 40 based on a preset priority order or the like. To do. Further, since there is a possibility that the request is retransmitted to the remaining virtual machines later, the request transfer unit 26 transmits the accepted request to the request storage unit 27 (step S117), and this request is sent to the request storage unit 27. Save temporarily.

  In step S <b> 116, when the priority order of the worker virtual machine 30 is higher than that of the worker virtual machine 40, the request transfer unit 26 first transfers the request to the port number of the internal port of the worker virtual machine 30. In the worker virtual machine 30, when the request receiving unit 33 of the worker HTTP server 31 accepts the request, the request is interpreted in the same manner as the request receiving unit 23 (step S118), and then it is determined to which web application the request is distributed. The application management unit 35 is handed over (step S119).

  The application management unit 35 refers to the correspondence table and searches for a Web application corresponding to the URL included in the request received from the request reception unit 33 (step S120). However, the web applications 32a and 32b operating on the worker virtual machine 30 do not include a web application corresponding to the requested URL. Therefore, the application management unit 35 uses the RPC (inter-VM communication) to inquire whether there is a web application corresponding to the requested URL from the other worker virtual machine 40 via the web application 32a ( Steps S121 and S122). Note that, here, the inquiry is made via the Web application 32a. However, the invention is not limited to this, and the inquiry may be made via another Web application (32b) operating on the worker virtual machine 30.

  On the other hand, the Web application 42a (42b) of the worker virtual machine 40 that has received the inquiry determines whether the Web application corresponding to the requested URL corresponds to itself (step S123). Here, when it is determined that the own Web application corresponds to the requested URL, the corresponding Web application 42a notifies the inquired Web application 32a of a response (TRUE) instructing that it corresponds to the URL. (Step S124). In the case of FIG. 8, the Web application 42b does not correspond to the requested URL, but in this case, the Web application 42b is notified of a response (FALSE) instructing that it does not correspond to the URL. As described above, the application management unit of the worker HTTP server to which the request has been transferred functions as an application survey unit that investigates whether or not another worker HTTP server has a corresponding application.

  When the web application 32a receives a response (TRUE) from another worker virtual machine 40 (web application 42a) (step S123), it indicates that the web application corresponding to the requested URL exists in the other worker virtual machine. The returned response is returned to the application management unit 35 (step S125). When receiving a response from the Web application 32a, the application management unit 35 transmits this response to the response transmission unit 34 (step S126). In response to the response (TRUE) received from the application management unit 35, the response transmission unit 34 transmits a preset special value status code (900 Forward Other) to the request transfer unit 26 of the master virtual machine 20. (Step S127).

  Upon receiving the status code from the worker virtual machine 30, the request transfer unit 26 determines whether or not the status code is a special value indicating that the status code exists in another worker virtual machine, that is, “900” ( Step S128). If the request transfer unit 26 determines that the status code is a special value indicating that it exists in another worker virtual machine, the request transfer unit 26 reads the request held in the request storage unit 27 (step S129), and The read request is transferred to the priority worker virtual machine (worker virtual machine 40) (step S130). Thus, only when the request transfer unit 26 of the master HTTP server 21 receives a response from the worker HTTP server that transferred the request that the other worker HTTP server has a corresponding application, Forward the request to the priority worker HTTP server.

  On the other hand, in the worker virtual machine 40, when the request receiving unit 43 receives the request, the request is interpreted in the same manner as the request receiving unit 23 (step S131). Next, the request reception unit 43 passes the request to the application management unit 45 in order to determine which Web application the request is distributed to (step S132). The application management unit 45 refers to the correspondence table and searches for a Web application corresponding to the URL included in the request received from the request reception unit 43 (step S133). Here, since the Web application 42a corresponds to the requested “app3.cgi”, the application management unit 45 determines that there is a corresponding Web application, and requests the Web application 42a to perform processing (step S134).

  When the requested processing is executed (step S135), the Web application 42a returns a status code “200” indicating that the processing with respect to the request has been successful to the application management unit 45 as a response (step S136). When receiving a response from the Web application 42a, the application management unit 45 transmits this response to the response transmission unit 44 (step S137). Further, when receiving a response from the application management unit 45, the response transmission unit 44 transmits this response to the request transfer unit 26 of the master virtual machine 20 (step S138).

  On the other hand, when the request transfer unit 26 of the master virtual machine 20 receives a response to the request transferred in step S129, a special value indicating that the status code included in this response exists in another worker virtual machine, that is, “ Whether or not “900” is determined (step S139). If the status code is not a special value (“200” in this process), the request transfer unit 26 transmits the received response to the response transmission unit 24 via the application management unit 25 (steps S140 and S141). Next, the response transmission unit 24 transmits the response received from the application management unit 25 to the HTTP client 100 (step S142).

  A case where the requested Web application does not exist in any virtual machine is also assumed. Therefore, referring to FIG. 9, processing when the request (GET /url/app4.cgi HTTP / 1.1) transmitted from the HTTP client 100 of the client apparatus 11 does not correspond to any Web application of each virtual machine. The flow will be described. Note that “app4.cgi” specified in the request does not correspond to any of the Web applications 22a to 22c, 32a, 32b, 42a, and 42b.

  When a request including “GET / url / app4.cgi HTTP / 1.1” is transmitted from the HTTP client 100 of the client apparatus 11 (step S151), the request receiving unit 23 of the master virtual machine 20 is similar to the above. The request is received and the content is interpreted (step S152). Then, the request reception unit 23 delivers the request to the application management unit 25 in order to determine which Web application the request is distributed to (step S153).

  The application management unit 25 refers to the correspondence table and searches for a Web application corresponding to the URL included in the request received from the request reception unit 23 (step S154). In this case, the Web application corresponding to the URL cannot be found on the master virtual machine 20. Therefore, the application management unit 25 requests the request transfer unit 26 to transfer the request to the worker HTTP server 31 or the worker HTTP server 41 operating on the worker virtual machine 30 (step S155).

  When receiving the transfer request from the application management unit 25, the request transfer unit 26 transfers the request to the port number of the internal port opened by the worker virtual machine 30 or 40 (step S156). Also in this case, since the URL registered in the application management unit 25 is the same, the request transfer unit 26 transfers the request to one of the two worker virtual machines 30 and 40 based on a preset priority order or the like. To do. Further, since there is a possibility that the request will be retransmitted to the remaining virtual machines later, the request transfer unit 26 transmits the received request to the request storage unit 27 (step S157), and this request is sent to the request storage unit 27. Save temporarily.

  If the priority of the worker virtual machine 30 is higher than that of the worker virtual machine 40 in step S156, the request transfer unit 26 first transfers the request to the port number of the internal port of the worker virtual machine 30. In the worker virtual machine 30, when the request reception unit 33 of the worker HTTP server 31 receives the request, the request is interpreted in the same manner as the request reception unit 23 (step S158), and in order to determine which Web application the request is distributed to, The application management unit 35 is handed over (step S159).

  The application management unit 35 refers to the correspondence table and searches for a Web application corresponding to the URL included in the request received from the request reception unit 33 (step S160). However, the web applications 32a and 32b operating on the worker virtual machine 30 do not include a web application corresponding to the requested URL. Therefore, the application management unit 35 uses the RPC (inter-VM communication) to inquire whether there is a web application corresponding to the requested URL from the other worker virtual machine 40 via the web application 32a ( Steps S161 and S162). Note that, here, the inquiry is made via the Web application 32a. However, the invention is not limited to this, and the inquiry may be made via another Web application (32b) operating on the worker virtual machine 30.

  On the other hand, the Web application 42a (42b) of the worker virtual machine 40 that has received the inquiry determines whether the Web application corresponding to the requested URL corresponds to itself (step S163). In the case of this processing, since there is no Web application corresponding to the requested URL, the Web application 42a (42b) inquires a response (FALSE) instructing that it does not correspond to the requested URL. The web application 32a is notified (step S164).

  When the Web application 32a receives response (FALSE) notifications from all the Web applications (42a, 42b) of the worker virtual machine 40 that has inquired, it indicates that there is no Web application corresponding to the requested URL. A response is returned to the application management unit 35 (step S165). When receiving a response from the Web application 32a, the application management unit 35 transmits this response to the response transmission unit 34 (step S166). In response to the response (FALSE) received from the application management unit 35, the response transmission unit 34 sends the status code “404” indicating the presence unknown in the HTTP protocol to the request transfer unit 26 of the master virtual machine 20. (Step S167).

  Upon receiving the status code from the worker virtual machine 30, the request transfer unit 26 determines whether or not the status code is a special value indicating that the status code exists in another worker virtual machine, that is, “900” ( Step S168). When the status code is not a special value (“404” in this process), the request transfer unit 26 transmits the received response to the response transmission unit 24 via the application management unit 25 (steps S169 and S170). Next, the response transmission unit 24 transmits the received response to the HTTP client 100 (step S171).

  Thus, when the request transfer unit 26 of the master HTTP server 21 receives a response from the worker HTTP server that transferred the request that it does not have an application corresponding to the request, the worker HTTP of the next priority order. The request is not transferred to the server, and a response indicating that the corresponding application does not exist is sent to the client. As a result, it is possible to prevent a request from being transferred to another virtual machine unnecessarily, and to speed up the response to the Web browser.

  As described above, according to the present embodiment, the master HTTP server 21 is a virtual machine that should process this request based on the correspondence table and the URL (address information) included in the request received from the HTTP client 100. And the request is transferred to the virtual machine. As a result, even if the developed Web application is added to an environment where a plurality of virtual machines operate, the request received from the HTTP client 100 can be appropriately distributed to the applications operating on each virtual machine.

  On the client side, a service by a Web application provided by a plurality of worker HTTP servers can be used only by accessing the HTTP server. Therefore, the client can use the service without being aware that a plurality of HTTP servers are operating.

  The present invention has been described with the above-described embodiments, but the present invention is not limited to the above-described embodiments, and those skilled in the art will conceive other embodiments, additions, changes, deletions, and the like. It can be changed within the range that can be performed, and any embodiment is included in the scope of the present invention as long as the operation and effect of the present invention are exhibited.

  Therefore, the above processing can be implemented as a program and executed by causing the server device to execute the program. This can also be provided as a computer-readable program as a recording medium such as a CD-ROM or memory card storing the program.

It is the figure which showed the structural example of the network apparatus containing a server apparatus as one Embodiment of the information processing apparatus of this invention. It is the figure which showed the module structure of information processing apparatus. It is the figure which showed the structure of the HTTP server. It is the sequence figure which showed the flow of registration of a Web application to a master HTTP server, and a request process. It is the sequence diagram which showed the flow of the process when the corresponding Web application is not found on the master virtual machine. It is the sequence figure which showed the flow of registration of a Web application to a worker HTTP server, and a request process. It is the sequence diagram which showed the flow of the process which registers the web application of the same URL, and a request process. FIG. 11 is a sequence diagram illustrating a flow of request processing when a corresponding Web application is not found on the first worker virtual machine and a corresponding Web application is found on the second worker virtual machine. It is the sequence diagram which showed the flow of the request processing when the corresponding web application does not exist on any virtual machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Server apparatus 11 Client apparatus 12 Network 20, 30, 40 Virtual machine 21, 31, 41 HTTP server 22a, 22b, 22c, 32a, 32b, 42a, 42b Web application 23, 33, 43 Request receiving part 24, 34, 44 Response transmitter
25, 35, 45 Application management unit 26 Request transfer unit 27 Request storage unit 28 Virtual machine control unit

Claims (13)

An information processing apparatus in which three or more virtual machines operate,
Each of the virtual machines holds, for each application running on its own virtual machine, first management information in which a file name and a file extension to be processed by the application are registered. An application management unit for determining an application corresponding to the file name and file extension included in the request received from the client as an application for processing the request ,
Among the plurality of virtual machines, one master virtual machine that receives a request from the client includes identification information for identifying each worker virtual machine other than the master virtual machine, and an application that operates on the worker virtual machine. Each of which holds second management information associated with at least a file extension to be processed, and an application operating on the worker virtual machine sends a request including the file extension to be processed to the client A request transfer unit that forwards the request to the worker virtual machine of the identification information corresponding to the file extension included in the request based on the second management information,
When a plurality of pieces of identification information corresponding to file identifiers included in the request are registered in the second management information, the request transfer unit of the master virtual machine has a predetermined priority order from the plurality of pieces of identification information. Forwards the request to the worker virtual machine of one identity selected based on
The application management unit of the worker virtual machine has an application corresponding to the file name and file extension included in the request transferred from the master virtual machine based on the first management information. If it is determined that the request exists, the result of processing the request using this application is transmitted to the client via the master virtual machine. If determined, investigate whether there is a corresponding application in another worker virtual machine other than its own worker virtual machine, and send this investigation result to the master virtual machine,
When the request transfer unit of the master virtual machine receives the investigation result indicating that there is an application corresponding to a worker virtual machine other than the worker virtual machine from the worker virtual machine that transferred the request, The request is forwarded to the worker virtual machine of the next priority identification information selected from the plurality of identification information, and the investigation result indicating that there is no application corresponding to any worker virtual machine is accepted. In this case, the information processing apparatus is characterized in that the request is not transferred to the worker virtual machine having the next priority order, and a response indicating that there is no corresponding application is transmitted to the client . The virtual machine includes an HTTP server running on its own virtual machine and at least one of the applications running on its own virtual machine,
The HTTP server includes the application management unit, a request reception unit that receives the request and extracts the address information included in the request, and a request transmission unit that transmits a processing result by the application as a response,
The HTTP server included in the master virtual machine is a master HTTP server including the request transfer unit that transfers the request, and the HTTP server included in the worker virtual machine processes the transferred request, and the processing result The information processing apparatus according to claim 1, wherein the information processing apparatus is a worker HTTP server that transmits. The information processing apparatus according to claim 2, wherein the master HTTP server transfers the request to the worker HTTP server using HTTP. The master HTTP server uses an external port to communicate with the outside of the information processing apparatus,
The worker HTTP server receives the request using an internal port and a loopback address for identifying the information processing device itself to communicate with the master HTTP server inside the information processing device, The information processing apparatus according to claim 3, wherein a processing result for the request is transmitted. The worker HTTP server acquires a URL of an application running on its own virtual machine using a remote procedure call, and registers the URL in the second management information of the master virtual machine. The information processing apparatus according to any one of the above. The request transfer unit of the master HTTP server, when acquiring the same URL from a plurality of worker HTTP servers, uses the same internal port for communicating with each of the worker HTTP servers as the identification information. The information processing apparatus according to claim 5, wherein the information processing apparatus registers the second management information in association with the URL. The master HTTP server further includes a request storage unit that stores the request received from the client, and a virtual machine control unit that stores priority information related to a priority order of transferring requests to the plurality of worker HTTP servers. Item 7. The information processing device according to Item 6. The request transfer unit of the master HTTP server has the following priority only when receiving a response from the worker HTTP server that transferred the request that the other worker HTTP server has a corresponding application. When the request is transferred to the worker HTTP server of the rank and a response indicating that the corresponding application is not received is received, the request is not transferred to the worker HTTP server of the next priority, A response indicating that the corresponding application does not exist is sent to the client;
The application management unit of the worker HTTP server to which the request has been transferred functions as an application survey unit that investigates whether the other worker HTTP server has the corresponding application, When it is detected that another worker HTTP server has the corresponding application, a response indicating that the corresponding application exists is transmitted, and when not detected, a response indicating that the corresponding application does not exist The information processing apparatus according to claim 6, which transmits An information processing method executed by an information processing apparatus in which three or more virtual machines operate,
Each of the virtual machines holds, for each of the applications running on its own virtual machine, first management information in which file names and file extensions to be processed by the application are registered, and the plurality of virtual machines The master virtual machine, which is one of the above, further includes identification information for identifying each worker virtual machine that is another virtual machine, and file extension that each of the applications running on the worker virtual machine processes. Holding the second management information associated with at least the child,
In the master virtual machine, when a request including a file extension to be processed by an application running on the worker virtual machine is received from the client, an identification corresponding to the file extension included in the request is received. A first determination step of determining whether a plurality of pieces of information are registered in the second management information;
In the first determination step, when it is determined that only one piece of identification information is registered, the request is transferred to the worker virtual machine of this identification information, and it is determined that a plurality of pieces of identification information are registered. A transfer step of transferring the request to the worker virtual machine of one identification information selected from among the plurality of identification information based on a predetermined priority,
In the worker virtual machine, whether or not an application corresponding to the file name and the file extension included in the request transferred from the master virtual machine exists in the worker virtual machine based on the first management information A second determination step for determining
In the second determination step, when it is determined that the corresponding application exists, the result of processing the request using the application is transmitted to the client via the master virtual machine, and the response When it is determined that there is no application to be checked, it is investigated whether there is a corresponding application in another worker virtual machine other than its own worker virtual machine, and the result is sent to the master virtual machine. A first transmitting step,
In the master virtual machine, when the investigation result indicating that there is an application corresponding to another worker virtual machine other than the worker virtual machine is received from the worker virtual machine that transferred the request, the plurality of identifications When the request is forwarded to the worker virtual machine of the next priority identification information selected from the information, and when the investigation result indicating that there is no application corresponding to any worker virtual machine is received, A second transmission step of not transmitting the request to a worker virtual machine of the next priority and transmitting a response to the effect that there is no corresponding application to the client;
An information processing method including: The information processing method according to claim 9, wherein in the transfer step, the request is transferred from the master virtual machine to the worker virtual machine using HTTP. The worker virtual machine further includes obtaining a URL of an application running on the worker virtual machine using a remote procedure call.
  The registration method further includes a registration step of registering the URL acquired in the acquisition step in the second management information in the master virtual machine in association with identification information of the master virtual machine that acquired the URL. 10. The information processing method according to 10. In the registration step of the master virtual machine, when the same URL is obtained from a plurality of the worker virtual machines, the second management is performed by associating the identification information of each of the worker virtual machines with the same URL. The information processing method according to claim 11, registered in information. A program for processing a request from a client that can be read by an information processing apparatus in which three or more virtual machines operate,
Each of the virtual machines holds, for each of the applications running on its own virtual machine, first management information in which file names and file extensions to be processed by the application are registered, and the plurality of virtual machines The master virtual machine, which is one of the above, further includes identification information for identifying each worker virtual machine that is another virtual machine, and file extension that each of the applications running on the worker virtual machine processes. Holding the second management information associated with at least the child,
In the master virtual machine, when a request including a file extension to be processed by an application running on the worker virtual machine is received from the client, an identification corresponding to the file extension included in the request is received. A first determination step of determining whether a plurality of pieces of information are registered in the second management information;
In the first determination step, when it is determined that only one piece of identification information is registered, the request is transferred to the worker virtual machine of this identification information, and it is determined that a plurality of pieces of identification information are registered. A transfer step of transferring the request to the worker virtual machine of one identification information selected from among the plurality of identification information based on a predetermined priority,
In the worker virtual machine, whether or not an application corresponding to the file name and the file extension included in the request transferred from the master virtual machine exists in the worker virtual machine based on the first management information A second determination step for determining
In the second determination step, when it is determined that the corresponding application exists, the result of processing the request using the application is transmitted to the client via the master virtual machine, and the response When it is determined that there is no application to be checked, it is investigated whether there is a corresponding application in another worker virtual machine other than its own worker virtual machine, and the result is sent to the master virtual machine. A first transmitting step,
In the master virtual machine, when the investigation result indicating that there is an application corresponding to another worker virtual machine other than the worker virtual machine is received from the worker virtual machine that transferred the request, the plurality of identifications When the request is forwarded to the worker virtual machine of the next priority identification information selected from the information, and when the investigation result indicating that there is no application corresponding to any worker virtual machine is received, A second transmission step of not transmitting the request to a worker virtual machine of the next priority and transmitting a response to the effect that there is no corresponding application to the client;
For causing the information processing apparatus to execute the program.

Images