JP2004133839A - Device and program for distributing server - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To directly and meticulously control the decision of a distribution destination server on the basis of information included in data in a request message. <P>SOLUTION: A transmitting and receiving part 1a for receiving a request message from a client and transmitting a response message to the client, a distribution table 41 for setting a distribution rule and a control part 3a for controlling distribution are provided. The control part 3a determines the distribution destination server on the basis of results obtained by analyzing structured text data included in the request message received by the transmitting and receiving part 1a according to the distribution rule set in the distribution table 41 and transmits the response message including the destination of the determined distribution destination server to the client from the transmitting and receiving part 1a. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[0001] 1. Field of the Invention [0002] The present invention relates to a server for a Web service or an application (software for systemizing a client and a server) and a server distribution device located between the clients. The present invention relates to a server distribution apparatus and a program for determining a distribution destination server based on information of XML (extensible Markup Language) data included in a request message transmitted from a client to a server at the time of distribution, and distributing the request message. is there.
[0002]
2. Description of the Related Art Conventionally, server load distribution in a switch (distribution apparatus) or the like is performed by transmitting a request message from a client, such as a source IP (Internet Protocol) address, an SSL (Secure Socket Layer) ID, and an HTTP (Hypertext Transfer Protocol). ), A distribution destination server is determined based on a URL (Uniform Resource Locators) header, a HOST (host) header (address of a server), a User-Agent header (terminal type on a client side), and the like. In these distributions, the items that have been the key to the distribution are often limited (determined) as described above, and the application (program) itself determines the contents of the request, information about the client, etc. in the message. It has been difficult to directly and finely control the determination of the distribution destination server based on the information included in the data.
[0003]
For example, even if the client can set information related to distribution, the information is limited to information determined in advance for server distribution, such as priority information and metric (region) information. (For example, Japanese Patent Application No. 2002-2912, Japanese Patent Application No. 2002-4223, Japanese Patent Application No. 2002-87944, Patent Document 1 and Patent Document 2).
[0004]
[Patent Document 1]
JP-A-11-250020 [Patent Document 2]
JP 2000-132524 A
SUMMARY OF THE INVENTION The above-mentioned prior art has the following problems.
[0006]
For server distribution, the information is limited to predetermined information. Based on the information included in the data in the message, such as the contents of the request and information on the client, the distribution destination server is determined directly and finely. It was difficult to control.
[0007]
The present invention solves such a conventional problem, and searches a distribution key tag set in a distribution table from structured data such as XML data included in a request message. It is possible to determine the server set in the table as a distribution destination server, and also to enable the application such as a Web service to directly and finely perform server distribution control by freely setting a distribution key. The purpose is to do.
[0008]
FIG. 1 is a diagram illustrating the principle of the present invention. In FIG. 1, 1a is a transmitting / receiving unit, 3a is a control unit, and 41 is a distribution table.
[0009]
The present invention has the following means to solve the above-mentioned conventional problems.
[0010]
(1): a transmission / reception unit 1a for receiving a request message from a client and transmitting a response message to the client, a distribution table 41 for setting a distribution rule, and a control unit 3a for controlling distribution; 3a determines a distribution destination server based on a result of analyzing structured text data included in the request message received by the transmission / reception unit 1a in accordance with the distribution rule set in the distribution table 41, A response message including the destination of the determined distribution destination server is transmitted from the transmission / reception unit 1a to the client. Therefore, it is possible to directly and finely control the determination of the distribution destination server based on the information included in the data in the request message.
[0011]
(2): In the server distribution device of (1), the control unit 3a has a function of collecting the load status of the server as a distribution destination, and when determining a distribution destination server, the control unit 3a collects the server load. Use information. For this reason, it is possible to determine a server or the like that can process the fastest according to the load information of the server as the distribution destination.
[0012]
(3): In the server distribution device according to (1) or (2), the structured text data included in the request message is XML data, and the control unit 3 a As distribution rules to be set, an XML tag serving as a key of distribution, a distribution destination server or a server group to be applied when the XML tag exists in the XML data of the request message, a search end position of the key XML tag, and the like. A set of XML tags is set. For this reason, an unnecessary search can be eliminated and efficient processing can be performed with the XML tag that is the search end position.
[0013]
(4): In the server distribution apparatus of (1) to (3), when setting the distribution rules in the distribution table 41, the control unit 3a sets the priority of application of the distribution rules according to the setting order. Shall be shown. For this reason, it is possible to preferentially distribute to servers and the like that process quickly by priority.
[0014]
(5): transmitting / receiving means for receiving a request message from a client and transmitting a response message to the client, setting means for setting a distribution rule in a distribution table, and a structure included in the request message received by the transmitting / receiving means Based on the result of analyzing the converted text data according to the distribution rule set in the distribution table, a distribution destination server is determined, and a response message including the destination of the determined distribution destination server is transmitted from the transmission / reception unit to the client. As the control means for transmitting, a program for causing a computer to function or a computer-readable recording medium on which the program is recorded. Therefore, by installing this program on a computer, it is possible to easily provide a server distribution apparatus that can directly and finely control the determination of a distribution destination server based on information included in data in a request message. can do.
[0015]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Recently, a conventional web application is changing into a web service world. As a result, the client side has changed from a user (person) to a Web service (machine), and access to the server has been made using a standard data format called XML SOAP. As a result, from the time of the first access, information required for processing on the server side, such as the content of the requested processing and information on the client side, is set as XML data in the request message (SOAP message). For this reason, by using these XML data as a key for distribution, fine distribution can be performed from the first access.
(1): Description of configuration of server distribution apparatus FIG. 2 is an explanatory diagram of a distribution apparatus based on XML tag information. In FIG. 2, a distribution device that distributes a request message from a client to a plurality of servers based on XML tag information includes a message transmission / reception unit 1, a transmission message processing unit 2, an XML data analysis unit 3, a distribution table management unit. 4, a server information collection unit 5, a distribution destination determination unit 6, a distribution table 41, and server information 51.
[0016]
A distribution device based on XML tag information is placed between a client and a server of an application (Web service) via the Internet or an intranet, receives and transmits a message at a message transmitting / receiving unit 1, and transmits a message at a message processing unit 2. Is generated, the XML data analysis unit 3 analyzes the XML data that is the structured text data, and the distribution table management unit 4 manages a distribution table 41 that is a table for determining a distribution destination server. The information collection unit 5 collects the load status of the distribution destination server (stored as server information 51 in the storage unit), and the distribution destination determination unit 6 determines the distribution destination based on the analysis result and the distribution table 41.
[0017]
(2): Description of each function of server distribution apparatus In the following, the function of each unit constituting the distribution apparatus based on XML information will be described.
[0018]
{Circle around (1)} Description of the message transmitting / receiving unit The message transmitting / receiving unit 1 transmits and receives messages handled by the distributed device. The following messages are transmitted and received.
[0019]
-Application request message-Response message including the information of the distribution destination server to the client-Message related to registration, modification, deletion, and reference of distribution table-Message related to server information collection (2): Explanation of transmission message processing unit Transmission message processing unit In 2, the following processing is performed according to the distributed processing method.
[0020]
When transferring the request message directly to the determined distribution destination server Rewrite the destination IP address of the request message to the address of the distribution destination server.
[0021]
・ Send a response message containing the destination of the determined destination server to the client, and redirect the request. Create a response message that prompts access destination change (redirect) according to the format of the transport protocol that carries the message. Send to the client that sent the message.
[0022]
For example, when HTTP is used as the transport protocol, the following response message is created.
[0023]
The status code is set to a code (3xx) that defines the three hundreds indicating server redirection, and the URL of the distribution destination server is set to the Location header.
[0024]
{Circle around (3)} The XML data analysis unit 3 has an XML parser function which is a tool for structural analysis such as SAX (sax) and DOM (dom), and analyzes XML data included in the request message. The procedure is as follows.
[0025]
Process S1: The XML data analysis unit 3 obtains information on a key tag and an analysis end tag from the distribution table 41 managed by the distribution table management unit 4.
[0026]
Process S2: The XML data analysis unit 3 extracts a pair of key tag and end tag from the set of tag information obtained above.
[0027]
(If there is a pair of key tag and end tag that can be taken out)
The key tag and the end tag are compared with the extracted tag in order from the head tag of the XML data (comparison with all of the distribution table 41 as described below).
[0028]
If it matches the key tag, store the tag as a matching key tag, and go to process S2. If it matches the end tag, go to process S2. If it reaches the end of the XML data, go to process S2. If there is no pair)
Step S3: Step S3: The XML data analysis unit 3 sends the information of the matching key tag to the distribution destination determination unit 6, and ends the XML data analysis process.
[0029]
{Circle around (4)} Description of the distribution destination determination unit The distribution destination determination unit 6 determines the distribution destination server according to the result of the key tag extraction by the XML data analysis unit 3 and the distribution destination server information (distribution table) managed by the distribution table management unit 4. And sends the result to the message processing unit 2. That is, the following processing is performed.
[0030]
Process S1: The distribution destination determination unit 6 queries the distribution table management unit 4 about the distribution destination server corresponding to the matching key tag information.
[0031]
-If the distribution destination is a server group, perform the following processing.
[0032]
(When using server information)
The server information collection unit 5 is inquired about the performance and load status of the server, and the information is used to determine the server as the distribution destination server.
[0033]
(When server load information is not used)
One server is selected from the distribution destination server group and determined as the distribution destination server.
[0034]
Process S2: The distribution destination determination unit 6 sends the determined distribution destination server to the message processing unit 2.
[0035]
{Circle around (5)} Description of the distribution table management unit The distribution table management unit 4 registers and manages the distribution table 41 storing the distribution rules. It also responds to inquiries about table references from the XML data analysis unit 3 and the distribution destination determination unit 6. The registration, change, and deletion of the distribution rule are performed by the application administrator according to the type of processing performed by the application, the configuration and status of the distribution destination server, and the like.
[0036]
The items managed as the distribution rules are as follows.
[0037]
Key XML tag An XML tag serving as a key for distribution. It is specified using a specification that can specify the position of the XML tag in the XML document, such as standard XPath.
[0038]
Search end XML tag Key An XML tag indicating the position where the search for the XML tag ends. It is specified using a specification that can specify the position of the XML tag in the XML document, such as XPath.
[0039]
-Distribution destination server or server group (selection rules for multiple servers)
{Circle around (6)} Description of server information collecting unit The server information collecting unit 5 collects information such as the performance and load status of the distribution destination server (for example, periodically) and stores it as server information 41, and the distribution destination determination unit 6 Responds to inquiries about server information.
[0040]
With such a server distribution apparatus, server distribution can be performed using XML tag information in XML data included in an application message as a key. This makes it possible to realize fine-grained server distribution based on a wide range of information and conditions, such as the contents of request messages and the functions provided by the server. Also, the side managing the application (usually the person managing the server) can directly control the server distribution.
[0041]
(2): Description of XML switch A description will be given of a case where the server distribution device of the present invention is mounted in a switch device that determines a distribution destination server based on a request message from a client and operates as an XML switch.
[0042]
FIG. 3 is an explanatory diagram of an example of using an XML switch. In FIG. 3, clients a and b are connected to servers A, B and C via an XML switch 10 on the Internet or an intranet. Here, an example in which priority control is performed based on the Priority information of the request message M1 from the client a and an example in which server distribution control is performed based on the regional information of the request message M2 from the client b are shown.
[0043]
{Circle around (1)} Description when server information is not used FIG. 4 is an explanatory diagram of a distribution table. In FIG. 4, two rules are set in the distribution table 41, and the setting order indicates that the application priority of the rule 1 is high. Each rule shows a key tag, a search end tag, and a distribution destination server. The search end tag may be omitted, but is provided to eliminate unnecessary search processing.
[0044]
FIG. 5 is an explanatory diagram of the flow of processing in the XML switch. Hereinafter, the flow of the processing in the XML switch according to the processing (1) to the processing (7) in FIG. 5 will be described by taking a request message (see FIG. 3) of the client a as an example.
[0045]
Process (1): The message transmitting / receiving unit 1 receives a request message from the client a and sends it to the XML data analyzing unit 3.
[0046]
Process (2): The XML data analysis unit 3 obtains a set of a key tag and a search end tag from the distribution table management unit 4.
[0047]
Process (3): The XML data analysis unit 3 searches for the first key tag and the search end tag from the beginning of the XML data of the message.
[0048]
Process {circle around (4)}: The XML data analysis unit 3 searches the XML data for a key tag of rule 1 and sends it to the distribution destination determination unit 6 as a matching key tag.
[0049]
Process (5): The distribution destination determination unit 6 obtains distribution destination information on the matching key tag from the distribution table management unit 4.
[0050]
Process (6): The distribution destination determination unit 6 determines servA as the distribution destination server based on the information obtained above, and sends the distribution destination server to the message processing unit 2.
[0051]
Process (7): The message processing unit 2 changes the destination of the request message to “servA” and transmits the request message.
[0052]
{Circle around (2)} Explanation when server information is used An example in which a server distribution apparatus is mounted in a switch device, operated as an XML switch, and the server performance and load status are taken into consideration when determining a distribution destination server. explain.
[0053]
FIG. 6 is an explanatory diagram of the distribution table. In FIG. 6, two rules are set in the distribution table 41, and the setting order indicates that the application priority of the rule 1 is high. Each rule shows a key tag, a search end tag, and a distribution destination server. The fastest server (the server that can process the fastest) is specified as the distribution destination of Rule 1.
[0054]
FIG. 7 is an explanatory diagram of the flow of processing using server information. Hereinafter, the flow of the processing in the XML switch according to the processing (1) to the processing (8) in FIG. 7 will be described using a request message (see FIG. 3) of the client a as an example.
[0055]
Process (1): The message transmitting / receiving unit 1 receives a request message from the client a and sends it to the XML data analyzing unit 3.
[0056]
Process (2): The XML data analysis unit 3 obtains a set of a key tag and a search end tag from the distribution table management unit 4.
[0057]
Process (3): The XML data analysis unit 3 searches for the first key tag and the search end tag from the beginning of the XML data of the message.
[0058]
Process {circle around (4)}: The XML data analysis unit 3 searches the XML data for a key tag of rule 1 and sends it to the distribution destination determination unit 6 as a matching key tag.
[0059]
Process (5): The distribution destination determination unit 6 obtains distribution destination information (the server that can process the fastest) for the matching key tag from the distribution table management unit 4.
[0060]
Process (6): The distribution destination determination unit 6 obtains information on the performance and load status of each server from the server information collection unit 5.
[0061]
Process (7): The distribution destination determination unit 6 determines the distribution destination server (for example, servA) as the distribution destination server based on the server information obtained in the above process (6), and sends it to the message processing unit 2.
[0062]
Process (8): The message processing unit 2 changes the destination of the request message to “servA” and transmits the request message.
[0063]
(3): Description of Redirect Server A case where the server distribution apparatus is operated as a redirect server will be described. Here, an example in which HTTP is used as the transport protocol will be described.
[0064]
FIG. 8 is an explanatory diagram of an example of using a redirect server. In FIG. 8, clients a and b are connected to a redirect server 20 and servers A, B, and C on the Internet or an intranet. Here, an example in which priority control is performed based on the Priority information of the request message M1 from the client a and an example in which server distribution control is performed based on the regional information of the request message M2 from the client b are shown.
[0065]
{Circle around (1)} Description of redirect server not using server information FIG. 9 is an explanatory diagram of the flow of processing in the redirect server. Hereinafter, the flow of the processing in the redirect server according to the processing (1) to the processing (7) in FIG. 9 will be described using a request message (see FIG. 8) of the client a as an example. 4 is used as an example of the distribution table 41 to be applied.
[0066]
Process (1): The message transmitting / receiving unit 1 receives a request message from the client a and sends it to the XML data analyzing unit 3.
[0067]
Process (2): The XML data analysis unit 3 obtains a set of a key tag and a search end tag from the distribution table management unit 4.
[0068]
Process (3): The XML data analysis unit 3 searches for the first key tag and the search end tag from the beginning of the XML data of the message.
[0069]
Process {circle around (4)}: The XML data analysis unit 3 searches the XML data for a key tag of rule 1 and sends it to the distribution destination determination unit 6 as a matching key tag.
[0070]
Process (5): The distribution destination determination unit 6 obtains distribution destination information on the matching key tag from the distribution table management unit 4.
[0071]
Process (6): The distribution destination determining unit 6 determines the server A (server A) as the distribution destination server based on the information obtained in the process (5), and sends the distribution destination server to the message processing unit 2.
[0072]
Process {circle around (7)}: The message processing unit 2 creates an HTTP response in which a redirection code, for example, 303 (Server Redirect See Other) is set as the status code, and a URL of servA is set in the Location header, and the client a which is the sender of the request message is created. Send to.
[0073]
As a result, the client a sends the request message directly to the server A.
[0074]
{Circle over (2)} Description of Redirect Server Using Server Information An example will be described in which a server distribution apparatus is operated as a redirect server and server performance and load conditions are taken into account when determining a distribution destination server.
[0075]
FIG. 10 is an explanatory diagram of the flow of processing using server information. Hereinafter, the flow of processing in the XML switch according to the processing (1) to the processing (8) in FIG. 10 will be described using a request message (see FIG. 8) of the client a as an example. The distribution table 41 shown in FIG. 6 is used as an example.
[0076]
Process (1): The message transmitting / receiving unit 1 receives a request message from the client a and sends it to the XML data analyzing unit 3.
[0077]
Process (2): The XML data analysis unit 3 obtains a set of a key tag and a search end tag from the distribution table management unit 4.
[0078]
Process (3): The XML data analysis unit 3 searches for the first key tag and the search end tag from the beginning of the XML data of the message.
[0079]
Process {circle around (4)}: The XML data analysis unit 3 searches the XML data for a key tag of rule 1 and sends it to the distribution destination determination unit 6 as a matching key tag.
[0080]
Process (5): The distribution destination determination unit 6 obtains distribution destination information (fastest server) related to the matching key tag from the distribution table management unit 4.
[0081]
Process (6): The distribution destination determination unit 6 obtains information on the performance and load status of each server from the server information collection unit 5.
[0082]
Process (7): The distribution destination determination unit 6 determines the distribution destination server (for example, servA) as the distribution destination server based on the server information obtained in the above process (6), and sends it to the message processing unit 2.
[0083]
Process (8): The message processing unit 2 creates an HTTP response in which a redirection code, for example, 303 (Server Redirect See Other) is set as the status code, and a URL of servA is set in the Location header, and the client a that is the sender of the request message is created. Send to.
[0084]
As a result, the client a sends the request message directly to the server A (servA).
[0085]
As described in the embodiment, when a request from a client is distributed to a plurality of servers, a distribution destination server is determined based on XML information included in a message exchanged between the server and the client. Fine distribution according to the content of the request and the function of the server becomes possible. Further, the application can directly control server distribution by setting an XML tag that is a key of distribution in the message.
[0086]
(4): Description of program installation Transmission / reception unit 1a, message transmission / reception unit 1, transmission message processing unit 2, control unit 3a, XML data analysis unit 3, distribution table management unit 4, server information collection unit 5, distribution destination determination unit 6 , The distribution table 41, the server information 51, and the like can be configured by a program, executed by the main control unit (CPU), and stored in the main memory. This program is processed by a computer. This computer is configured by hardware such as a main control unit, a main storage, a file device, an output device such as a display device and a printing device, and an input device.
[0087]
The program of the present invention is installed on this computer. In this installation, these programs are stored in a portable recording (storage) medium such as a floppy disk, a magneto-optical disk, or the like, and a drive device for accessing a recording medium provided in the computer is used. Alternatively, it is installed in a file device provided in a computer via a network such as a LAN.
[0088]
As described above, according to the present invention, the following effects can be obtained.
[0089]
(1): The control unit determines the distribution destination server based on the result of analyzing the structured text data included in the request message received by the transmission / reception unit according to the distribution rule set in the distribution table. In order to transmit a response message including the destination of the determined distribution destination server to the client from the transmission / reception unit, the determination of the distribution destination server is directly and finely controlled based on information included in the data in the request message. can do.
[0090]
(2): Since the control unit uses the collected server load information when determining the distribution destination server, it is possible to determine the server that can process the fastest according to the server load information as the distribution destination. .
[0091]
(3): As a distribution rule to be set in the distribution table, an XML tag that is a key of distribution, a distribution destination server or a server group that is applied when the XML tag exists in the XML data of the request message, and the key Since a set of XML tags serving as the search end position of the XML tag is set, an unnecessary search can be eliminated with the XML tag serving as the search end position, and efficient processing can be performed.
[0092]
(4): When setting the distribution rules in the distribution table by the control unit, the setting order indicates the priority of application of the distribution rules. Can be dispersed.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the principle of the present invention.
FIG. 2 is an explanatory diagram of a distribution apparatus based on XML tag information according to an embodiment.
FIG. 3 is an explanatory diagram of a usage example of an XML switch according to the embodiment;
FIG. 4 is an explanatory diagram of a distribution table according to the embodiment.
FIG. 5 is an explanatory diagram of a processing flow in an XML switch according to the embodiment;
FIG. 6 is an explanatory diagram of a distribution table according to the embodiment.
FIG. 7 is an explanatory diagram of a processing flow using server information according to the embodiment;
FIG. 8 is an explanatory diagram of a usage example of a redirect server in the embodiment.
FIG. 9 is an explanatory diagram of a processing flow in a redirect server in the embodiment.
FIG. 10 is an explanatory diagram of a flow of processing using server information according to the embodiment;
[Explanation of symbols]
1a Transmission / Reception Unit 3a Control Unit 41 Distribution Table

Claims (5)

A transmitting / receiving unit that receives a request message from a client and transmits a response message to the client;
A distribution table for setting distribution rules;
A control unit for controlling dispersion,
The control unit determines the distribution destination server based on the result of analyzing the structured text data included in the request message received by the transmission / reception unit according to the distribution rule set in the distribution table, A server distribution apparatus, wherein a response message including a destination of the determined distribution destination server is transmitted from the transmission / reception unit to a client. The server according to claim 1, wherein the control unit has a function of collecting a load status of a distribution destination server, and uses the collected server load information when determining a distribution destination server. Dispersion equipment. The structured text data included in the request message is XML data,
The control unit includes, as distribution rules to be set in the distribution table, an XML tag serving as a key of distribution, a distribution destination server or a server group applied when the XML tag exists in the XML data of the request message, 3. The server distribution apparatus according to claim 1, wherein a set of XML tags that is a search end position of the key XML tag is set. The distribution apparatus according to any one of claims 1 to 3, wherein the control unit, when setting distribution rules in the distribution table, indicates the priority of application of the distribution rules according to the setting order. A transmission / reception means for receiving a request message from the client and transmitting a response message to the client;
Setting means for setting a distribution rule in the distribution table;
A distribution destination server is determined based on a result of analyzing structured text data included in the request message received by the transmission / reception means according to a distribution rule set in the distribution table, and the determined distribution destination is determined. As control means for transmitting a response message including the destination of the server from the transmitting and receiving means to the client,
A program that makes a computer function.

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