JP2009110165A - Load balancing processing method in publish/subscribe communication, and execution device and processing program therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide load balancing constitution on a subscribe side (reception side), in publish/subscribe communication. <P>SOLUTION: A proxy publish/subscribe (pub/sub) communication node is arranged between a communication node for executing the publish/subscribe communication and a broker for executing message communication. The proxy publish/subscribe communication node issues a publish/subscribe request to the broker, as a proxy of a plurality of connected communication nodes. The subscribe request is issued to the broker only when receiving the first request, when a proxy pub/sub server receives the subscribe request as the same topic from the plurality of nodes. When receiving the subsequent subscribe requests, only the communication node having issued the request is stored. When receiving a publish message to the topic from the broker, one of the plurality of stored communication nodes having issued the subscribe request is selected and distributed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to publish / subscribe communication, and relates to a load distribution processing method for executing distributed processing at each node by distributing distribution data to a plurality of nodes.

  A point-to-point method is widely used as a method for sending and receiving messages. This is a method in which the transmitting side transmits a message by specifying the destination on the receiving side, and it is necessary to be aware of the destination received by the transmitting side. On the other hand, there is a communication model called Publish-Subscribe method. In the Publish-Subscribe method, the sender issues a message without considering the destination (Publish), and the messaging system that receives the message looks at the message type and attributes and requests to subscribe to the message (subscribe). Deliver the message to the receiving party. In the Publish-Subscribe method, there is no need for the sending side and the receiving side to be aware of who and where the other party is, and the receiving side can receive only the messages that it needs. Since it is not necessary for the transmitting side and the receiving side to be aware of each other, the configuration can be easily changed such as adding and deleting services.

  In one example of a point-to-point and publish-subscribe messaging specification, the sender sends a message to a topic, and the message can be received by any application that subscribes to the topic. When all subscribed applications have been received, the message is deleted from the topic.

  The point-to-point method is one-to-one communication, whereas the publish-subscribe method is one-to-N communication. A stock price distribution system is an example in which the Publish-Subscribe method is applied to a real system. When a user registers a stock price subscription of a company, the updated stock price of the company is transmitted (Publish). The same information is notified to a plurality of users who have subscribed.

  As a communication configuration, a configuration in which each client program is connected to a message delivery node called a broker, and the brokers are further connected (Patent Document 1).

  By the way, in a system in which a large number of processing requests are generated from a large number of client programs, the server program operates by installing a load balancer between the device where the client program operates and the device where the server program operates. Generally, a configuration is adopted in which a plurality of processing devices are arranged to distribute the processing request load to a plurality of devices. This configuration can be applied when the point-to-point method is used for communication. However, when the Publish-Subscribe method is used, a message subscription request (subscribe) is made from a plurality of processing devices, so that the same message is distributed to a plurality of processing devices, and a load balancing configuration is adopted. I can't.

Special table 2006-523905

  As described above, in publish / subscribe communication, the sending side and the receiving side do not need to be aware of who and where the other party is, and the receiving side can receive only the message that it needs. If a load distribution processing system using communication is constructed, it is considered that it is possible to construct a load distribution processing system in which the transmission side and the reception side do not need to be aware of each other and the configuration can be easily changed such as addition and deletion of services. As described above, in the conventional technique, it is difficult to adopt a load distribution configuration when publish / subscribe communication is used.

  An object of the present invention is to solve the above-described problems and provide a technique capable of realizing a load sharing configuration on the subscribe side (receive side) in publish / subscribe communication.

  The present invention is a load distribution processing system that distributes a message by publish / subscribe communication and causes a plurality of nodes to execute load distribution processing. The first subscribing request for a certain topic is transmitted to a broker or selected one. The proxy server distributes the message from the broker to one node, so that processing using the message is distributed and executed by a plurality of nodes.

  In the present invention, a proxy publish / subscribe (pub / sub) communication node (proxy pub / sub server) is arranged between a communication node that performs publish / subscribe communication and a broker that executes message distribution. This proxy pub / sub server issues a publish / subscribe request to the broker as a proxy for a plurality of connected communication nodes.

  That is, in the load distribution processing method of the present invention, when the proxy pub / sub server receives a subscribe request on the same topic from multiple nodes, it issues a subscribe request to the broker only when the first request is received. When receiving a subsequent subscribe request, only remember which communication node received it, and issue a stored subscribe request when a publish message for that topic is received from the broker If the proxy pub / sub server receives an unsubscribe request for canceling the subscribe request from the communication node, all stored communications are included. Unsubscribe to the broker only when an unsubscribe request is received from the node To achieve load distribution processing by comprising sending a request.

  Also, by specifying the topic name to be processed according to the above steps in advance, you can select one of the communication nodes that issued the subscribe request and distribute the publish message, or you can issue all the subscribe requests as usual It is also possible to select whether to distribute the publish message to the communication node.

  According to the present invention, a load distribution configuration can be realized by arranging a plurality of subscribers in publish / subscribe communication.

  FIG. 1 shows an example of a publish / subscribe communication network. A broker 120 that manages message distribution between communication nodes, each communication node 101, and a proxy pub / sub server 130 that controls load distribution of publish / subscribe communication. The communication node 140 is connected to the proxy pub / sub server 130, and each device performs publish / subscribe communication via the network and the communication device. Here, the proxy pub / sub server 130 is a device, and the pub / sub server 104 and the pub / sub server 143 on the memory are programs.

  The communication node 101 includes a memory 103 and a CPU 102. In the memory 103, a pub / sub server 104 that controls publish / subscribe processing in the node and an application 105 that requests publish / subscribe are arranged.

  The communication node 140 is a node that provides a service to the communication node 101 connected to the broker, and includes a memory 141 and a CPU 142. In the memory 141, a pub / sub server 143 that controls publish / subscribe processing in the node, and a service A 144 and a service B 145 that provide services are arranged.

  The service A 144 and the service B 145 issue a subscribe request specifying a topic to the pub / sub server 143, and receive a message that matches the topic specified by the service A 144 and the service B 145 in the message published from the communication node 101. There are a plurality of communication nodes 140, all of which are connected to the proxy pub / sub server 130. The plurality of communication nodes 140 receive messages from the proxy pub / sub server 130 and load balance the processing of the service A 144 and the service B 145. To do.

  The proxy pub / sub server 130 includes a memory 132, a CPU 131, a topic definition unit 135, and a node list management unit 136. The memory 132 includes a topic detection unit 133 that controls publish / subscribe communication messages, and a load distribution unit 134 that distributes a message notified from the broker 120 to each communication node 140 and distributes the load. The topic detection unit 133 refers to and updates information of a topic definition unit 135 that manages a load distribution target topic and a node list management unit 136 that manages a node list that distributes and distributes messages of each topic.

  A program for causing the proxy pub / sub server 130 to function as the topic detection unit 133 and the load distribution unit 134 is recorded on a recording medium such as a CD-ROM and stored in a magnetic disk, and then loaded into a memory and executed. Shall be. The recording medium for recording the program may be a recording medium other than the CD-ROM. The program may be used by installing it from the recording medium into the information processing apparatus, or the program may be used by accessing the recording medium through a network.

  FIG. 2 shows the configuration of the topic definition unit 135. The topic definition unit 135 includes a plurality of records 211, 212, 213, and 214 including a topic identifier 201, a topic name 202, a matching pattern 203, and a node list name 204.

  In this embodiment, it is assumed that whether a message transmitted / received by the proxy pub / sub server 130 is a load distribution target is determined by the topic identifier 201 and the matching pattern 203. The matching pattern 203 includes “front” 221, “post” 222, and “whole” 223.

  When the topic name transmitted / received between the proxy pub / sub server 130 and the communication node 140 is matched with the topic name of the message transmitted / received between the communication node 101 connected to the broker 120, the “total” 223 is set as the matching pattern 203. Is set in advance. The record 213 is an example.

  When a topic name added to a topic name 201 in front of a topic name of a message transmitted / received between the communication nodes 101 connected to the broker 120 is used as a topic name transmitted / received between the proxy pub / sub server 130 and the communication node 140 In this case, “Prefix” 221 is set in the matching pattern 203. Records 211 and 212 are examples thereof. In the case of the record 211, the topic name between the broker 120 and the communication node 101 is “/ request_A”, but the topic name between the proxy pub / sub server 130 and the communication node 140 is “/ # LB_prefix / request_A”. In the case of the record 212, the topic name between the broker 120 and the communication node 101 is “/ request_B”, but the topic name between the proxy pub / sub server 130 and the communication node 140 is “/ # LB_prefix / request_B”.

  When the topic name of a message transmitted / received between the communication nodes 101 connected to the broker 120 is added with the topic identifier 201 as a topic name transmitted / received between the proxy pub / sub server 130 and the communication node 140, A “postfix” 222 is set in the matching pattern 203. In the case of the record 214, the topic name between the broker 120 and the communication node 101 is “/ request_C”, but the topic name between the proxy pub / sub server 130 and the communication node 140 is “/ request_C / # LB_prefix”.

  When “Prefix” 221 and “Postfix” 222 are designated as the matching pattern 203, the services 144 and 145 of the communication node 140 connected to the proxy pub / sub server 130 define all topics to be load-balanced in advance as topic definitions. It is not necessary to specify in the section 135, and when a service is added, a topic name based on a certain rule may be specified and subscribed. The node list name 204 indicates a list of load distribution target nodes of the corresponding topic, and indicates the position of the node list pointer 301 of the node list management unit 136.

  FIG. 3 shows the configuration of the node list management unit 136. The node list management unit 136 includes a node list pointer 301 and a node list 302. In the node list pointer 301, pointer areas 311, 312, 313, and 314 corresponding to the records 211, 212, 213, and 214 of the topic definition unit 135 are secured. In the node list 302, nodes 321 and 322 for load distribution pointed from the pointer area 311 are secured.

  FIG. 4 shows a flow in which the proxy pub / sub server 130 receives a subscribe request from the communication node 140. When the topic detection unit 133 of the proxy pub / sub server 130 receives the subscribe request (step 40), the topic detection unit 133 determines whether there is a matching topic in the topic definition unit 135 (step 41).

  If the result determined in step 41 is NO, the subscribe request acceptance process is terminated (step 47). If the result of determination in step 41 is YES, it is determined whether the same subscribe request as the accepted subscribe request has been transmitted to the broker 120 (step 42).

  If the determination result in step 42 is YES, the process proceeds to step 45. If the determination result in step 42 is NO, a subscribe request is recreated according to the matching pattern of the topic definition unit 135 (step 43), and the recreated subscribe request is transmitted to the broker 120 (step 44). .

  Next, it is determined whether there is a corresponding node in the node list management unit 136 (step 45). Only when the result determined in step 45 is NO, the node is added to the node list management unit 136 (step 46), and the subscription request acceptance process is terminated (step 47).

  FIG. 5 shows a flow of processing (step 41) for determining whether or not there is a matching topic in the topic definition unit 135. After the topic detection unit 133 of the proxy pub / sub server 130 starts the processing in step 50, whether the matching pattern 203 is “whole” 223 and a record having the same topic identifier 201 as the corresponding topic name exists. Determination is made (step 51).

  If the determination result in step 51 is YES, the final determination result is also YES (step 55), and the determination process is terminated (step 56). If the result of determination in step 51 is NO, it is determined whether the matching pattern 203 is “prefix” 221 and there is a topic identifier 201 that matches forward from the beginning of the corresponding topic name (step 52). ).

  If the determination result in step 52 is YES, the final determination result is also YES (step 55), and the determination process is terminated (step 56). If the determination result in step 52 is NO, it is determined whether the matching pattern 203 is “postfix” 222 and there is a topic identifier 201 that matches backward from the rear end of the topic name (step). 53).

  If the determination result in step 53 is YES, the final determination result is also YES (step 55), and the determination process is terminated (step 56). If the determination result in step 53 is NO, the final determination result is also NO (step 54), and the determination process is terminated (step 56).

  FIG. 6 shows a flow of processing (step 43) for re-creating a subscribe request according to the matching pattern of the topic definition unit 135. The topic detection unit 133 of the proxy pub / sub server 130 starts processing in step 60, and then determines whether the matching pattern 203 of the matched record in the topic definition unit 135 is “prefix” 221 (step 61). .

  If the result of the determination in step 61 is YES, the character string of the topic identifier 201 is deleted from the front of the corresponding topic name in the subscribe request (step 62). If the topic definition unit 135 does not have a record that matches the topic name created here, a record having the created topic name is added (step 63), and the process ends (step 67). If the result of the determination in step 61 is NO, it is determined whether the matching pattern 203 of the matched record in the topic definition unit 135 is “postfix” 222 (step 64).

  If the result of the determination in step 64 is YES, the character string of the topic identifier 201 is deleted from the back of the corresponding topic name in the subscribe request (step 65). If the topic definition unit 135 does not have a record that matches the topic name created here, a record having the created topic name is added (step 66), and the process ends (step 67). If the result determined in step 64 is NO, the process is terminated (step 67).

  FIG. 7 shows a flow of processing in which the proxy pub / sub server 130 receives a publish message issued from the communication node 101. The topic detection unit 133 of the proxy pub / sub server 130 determines whether there is a topic that matches the topic name 202 of the topic definition unit 135 after receiving the publish message in step 70 (step 71).

  If the result of the determination in step 71 is NO, the received publish message is transmitted to all the communication nodes 140 subscribed to the topic (step 75), and the publish message receiving process is terminated (step 76). ). If the result of determination in step 71 is YES, a publish message is recreated according to the matching pattern 203 of the topic definition unit 135 (step 72).

  Then, the node of the node list 302 of the node list management unit 136 is passed to the load distribution unit 134 to determine the destination (step 73). Here, the load distribution unit 134 selects one of the information of the corresponding node and selects a node to distribute the message. As described above, the load distribution unit 134 implements a mechanism for distributing the message allocation load to a plurality of nodes, but this load distribution mechanism is outside the scope of the present invention. Next, the load distribution unit 134 transmits a publish message to the determined destination (step 74), and ends the process (step 75).

  FIG. 8 shows a flow of processing (step 72) for recreating a publish message in accordance with the matching pattern 203 of the topic definition unit 135. The topic detection unit 133 of the proxy pub / sub server 130 starts the processing in step 80, and then has a topic that matches the topic name 202 of the topic definition unit 135 and the matching pattern 203 is “Prefix” 221. Is determined (step 81).

  If the result of the determination in step 81 is YES, the topic identifier 201 of the topic definition unit 135 is added in front of the topic (step 82), and the process ends (step 85). If the determination result in step 81 is NO, it is determined whether there is a topic that matches the topic name 202 of the topic definition unit 135 and the matching pattern 203 is “postfix” 222 (step 83). If the result of the determination in step 83 is YES, the topic identifier 201 of the topic definition unit 135 is added behind the corresponding topic (step 84), and the process ends (step 85).

  FIG. 9 shows a flow in which the proxy pub / sub server 130 receives an unsubscribe request from the communication node 140. When the topic detection unit 133 of the proxy pub / sub server 130 receives the unsubscribe request in Step 90, the topic detection unit 133 determines whether there is a topic that matches the topic definition unit 135 (Step 91). The flow of this determination process is shown in FIG.

  If the result of the determination in step 91 is NO, the unsubscribe request acceptance process ends (step 98). If the result determined in step 91 is YES, the corresponding node in the node list 302 of the node list management unit 136 is deleted (step 92).

  Next, it is determined whether one or more nodes pointed to by the corresponding node list pointer of the node list management unit 136 exist (step 93). If the result of the determination in step 93 is YES, the unsubscribe request acceptance process ends (step 98). If the result determined in step 93 is NO, an unsubscribe request is recreated according to the matching pattern of the topic definition part (step 94). Then, the re-subscribed unsubscribe request is transmitted to the broker 120 (step 95). Next, when the result determined in step 93 is NO, the topic name 202 of the corresponding record in the topic definition unit 135 is cleared (step 96). Then, only when there is another record with the same topic identifier 201, the corresponding record is deleted, and the unsubscribe request acceptance process is terminated (step 98).

  FIG. 10 shows a flow of processing (step 94) for recreating an unsubscribe request according to the matching pattern of the topic definition unit. The topic detection unit 133 of the proxy pub / sub server 130 starts processing in step 101, and then determines whether the matching pattern 203 of the matched record in the topic definition unit 135 is “prefix” 221 (step 102). .

  If the result of the determination in step 102 is YES, the character string of the topic identifier 201 is deleted from the front of the corresponding topic name in the unsubscribe request (step 103), and the process is terminated (step 106). If the result of determination in step 102 is NO, it is determined whether the matching pattern 203 of the matched record in the topic definition unit 135 is “postfix” 222 (step 104).

  If the result of the determination in step 104 is YES, the character string of the topic identifier 201 is deleted from the back of the corresponding topic name in the subscribe request (step 105), and the process is terminated (step 106). If the result determined in step 104 is NO, the process ends (step 106).

  As described above, in the load balancing processing system of this embodiment, the proxy server performs transmission of the first subscribe request on a certain topic to the broker and delivery of the message from the broker to one selected node. Since processing using a message is distributed and executed by a plurality of nodes, a load sharing configuration can be realized by arranging a plurality of subscribers in publish / subscribe communication.

  In the load distribution processing system described above, whether the message transmitted / received by the proxy pub / sub server 130 is a load distribution target is determined by the topic identifier 201 and the matching pattern 203 of the topic definition unit 135. The information indicating the topic to be stored in the storage device as a table other than the topic definition unit 135 in advance, and the subscribe request topic matches the topic in the table stored in the storage device. Select one of the multiple communication nodes that issued the live request and distribute the publish message to perform load distribution processing. Otherwise, the publish message is sent to all the communication nodes that issued the subscribe request as usual. May be distributed.

It is a figure which shows the network of the publish / subscribe communication of this embodiment. It is a figure which shows the topic definition part of this embodiment. It is a figure which shows the node list management part of this embodiment. It is a figure which shows the flow when the subscribe request | requirement of this embodiment is received. It is a figure which shows the flow which determines whether there exists a topic which corresponds to the topic definition part of this embodiment. It is a figure which shows the flow which recreates the subscription request | requirement of this embodiment. It is a figure which shows the flow which receives the publish message of this embodiment. It is a figure which shows the flow which recreates the publish message of this embodiment. It is a figure which shows the flow when the unsubscribe request | requirement of this embodiment is received. It is a figure which shows the flow which recreates the unsubscribe request | requirement of this embodiment.

Explanation of symbols

101, 140 ... communication node, 102, 131, 142 ... CPU, 103, 132, 141 ... memory, 104, 143 ... pub / sub server, 105 ... application, 144, 145 ... service, 120 ... broker, 130 ... proxy pub / sub server, 133 ... topic detection unit, 134 ... load distribution unit, 135 ... topic definition unit, 136 ... node list management unit, 201 ... topic identifier, 202 ... topic name, 203 ... match pattern, 204 ... node list name, 211, 212, 213, 214 ... Topic definition section record, 221, 222, 223 ... Match pattern type, 301 ... Node list pointer, 311, 312, 313, 314 ... Pointer area, 302 ... Node list, 321, 322 ... node area, 40-47 ... accept subscribe request 50-56... Each process of the flow for determining whether or not there is a topic matching the topic definition part, 60 to 67... Each process of the flow for regenerating a subscribe request, 70 to 75. Each process of a flow that receives a publish message, 80 to 85... Each process of a flow that recreates a publish message, 90 to 98... Each process of a flow when an unsubscribe request is accepted, 101 to 106. Each process in the flow to recreate the request

Claims (5)

A load distribution processing method in a proxy server that distributes a message by publish / subscribe communication and causes a plurality of nodes to execute load distribution processing,
A proxy server interposed between a plurality of nodes requesting to subscribe to a message of the same topic and a broker delivering the message sends a first subscribe request of a topic to the broker through a communication device, and subscribes to the topic. Storing information indicating a node that transmitted a live request in a storage device, and information indicating a node that transmitted a subscribe request for the topic when the proxy server receives the topic message from the broker. The processing using the message is distributed among the plurality of nodes by having a step of reading from the storage device, selecting one of the read information, and distributing the message to the selected node by a communication device. The load distribution processing method is characterized by:   When each node issues an unsubscribe request to stop subscribing a message of a topic, and the proxy server receives the unsubscribe request from all the nodes that have accepted the subscribe request for the topic, the topic 2. The message unsubscribe request is transmitted to the broker by a communication device, and all the information indicating the node that transmitted the topic subscribe request is deleted from the storage device. Load balancing processing method.   Information indicating a topic to be load-balanced is stored in a storage device in advance, and when the subscribe request topic matches the topic stored in the storage device, load distribution processing is performed by distributing the message. The load distribution processing method according to claim 1, wherein the load distribution processing method is performed. A proxy server that distributes messages via publish / subscribe communication and allows multiple nodes to execute load balancing processing.
It is interposed between a plurality of nodes that request to subscribe to messages of the same topic and a broker that distributes the messages, and the first subscribe request of a topic is transmitted to the broker by a communication device, and the subscribe request for the topic is transmitted. A topic detection unit that stores information indicating the transmitted node in a storage device, and when receiving a message of the topic from the broker, reads information indicating the node that transmitted a subscribe request for the topic from the storage device; A load distribution unit that selects one of the read information and distributes the message to the selected node by a communication device, and distributes and executes processing using the message in the plurality of nodes A proxy server characterized by that. A program for causing a computer to execute a load distribution processing method in a proxy server that distributes a message by publish / subscribe communication and causes a plurality of nodes to execute load distribution processing,
A proxy server interposed between a plurality of nodes requesting to subscribe to a message of the same topic and a broker delivering the message sends a first subscribe request of a topic to the broker through a communication device, and subscribes to the topic. Storing information indicating a node that transmitted a live request in a storage device, and information indicating a node that transmitted a subscribe request for the topic when the proxy server receives the topic message from the broker. The processing using the message is distributed among the plurality of nodes by having a step of reading from the storage device, selecting one of the read information, and distributing the message to the selected node by a communication device. Execute the load balancing processing method to be executed on the computer Program for causing.

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