JP2010072894A - Information distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for preventing the load of a specific distribution server from being increased, and for connecting clients with a plurality of distribution servers. <P>SOLUTION: When a client is connected to a distribution server to receive distribution information, the distribution server dynamically changes the connection destination of the client according to the operating conditions of the distribution server (the number of clients under control or a disabled state due to failure or the like). Thus, it is possible to reduce the load of the distribution server. Specifically, each distribution server is provided with distribution information to be distributed to each client and a distribution server list. Each distribution server is configured to communicate with each of the other distribution servers at predetermined time intervals, to acquire the load conditions of each of the other distribution servers, and to store it in the distribution server list. When a request to acquire distribution information is made from the client, and when the load of the server is high, the distribution server issues an instruction to connect the client again to the low-load distribution server by referring to the distribution server list. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for distributing setting information for controlling client operations from a distribution server in a client server type security system including a client that acquires and reflects setting information for controlling client operations from a distribution server, for example. Is.

  Conventionally, various setting information for defining the operation of a client is stored in a distribution server that centrally manages the setting information of the client. Each client connects to the distribution server, acquires setting information, and operates based on the acquired setting information.

  However, since there is basically only one distribution server, when the number of managed clients increases, the number of connection requests to the distribution server also increases and the load on the distribution server increases. In particular, client setting information should be kept up-to-date in order to ensure high security. Therefore, when setting information is updated, it is desirable to promptly set all client setting information. Therefore, when the setting information is updated, even if the data volume of the setting information is small, distribution requests from many clients are temporarily concentrated, and the load on the distribution server may increase. Further, when a failure occurs in the distribution server, the client cannot acquire setting information from the distribution server.

As a solution to the increase in server load or the stop of distribution processing when a failure occurs in a server, a method of installing a plurality of servers, such as Patent Document 1 below, is generally known.
JP 2006-113735 A

  However, in an environment where a plurality of servers exist, it becomes a problem which server the client connects to. That is, even in an environment where a plurality of servers exist, there may be a disadvantage that the load on a specific server increases.

  An object of the present invention is to provide a technique for distributing client connections by eliminating a situation in which the load on a specific distribution server increases when there are a plurality of distribution servers.

  In order to achieve the above object, according to the present invention, when a client connects to a distribution server and receives distribution information, the distribution server determines the connection status of the client (the number of managed clients, failures, etc.) It is characterized in that the load on the distribution server is reduced by dynamically changing it according to whether or not it is in a situation where it cannot be operated at the same time. That is, the present invention includes a plurality of distribution servers that send predetermined distribution information to clients and a plurality of clients that receive distribution information from these distribution servers, and each distribution server distributes distribution information to each client. And a list of all distribution servers. This distribution server list stores connection destination addresses, operating states, and current load states of all distribution servers. As the current load status, for example, the number of clients managed by each distribution server may be used, but the load status may be expressed by another index.

  Each distribution server communicates with each other distribution server every predetermined time, acquires the load status of each other distribution server, and stores it in the distribution server list. It is assumed that the distribution server that could not communicate is not operating, and information indicating that it is not operating is stored in the entry of the distribution server in the distribution server list. Further, each distribution server determines whether or not the load status of the own device reaches a predetermined load level every predetermined time, and if so, the load status of the own device reaches the predetermined load level. When the message is not reached, the other server is notified of the operating status of its own device. As a result, the distribution server that was in a state where communication is not possible notifies the other distribution server of the operation status of its own device when communication is possible, so that other distributions can be notified that communication is possible. Can inform the server. The same applies when a completely new distribution server is added.

  In each client, one of the distribution servers is set as a connection destination in advance as an initial value, and is connected to the set distribution server at the time of activation. When the distribution server receives the distribution information acquisition request from the client, the distribution server determines whether or not the load status of the own device has reached a predetermined load level. For example, the number of clients currently managed may be checked. When the load status of the distribution server reaches a predetermined load level, the distribution server identifies a distribution server with a low load by referring to the distribution server list, and reconnects the client to the identified distribution server. To instruct. Further, it notifies the other distribution servers that the load status of the own device has reached the predetermined load level. The other distribution server that has received the notification stores the fact in an entry indicating the distribution server in the distribution server list. When instructed by the distribution server to change the connection destination, the client connects to the changed connection destination distribution server.

The method of the present invention has the following effects.
(1) When a load on a specific distribution server increases (for example, an increase in the number of clients to be managed), the client causes the distribution server to manage the load at a low load (for example, a small number of clients to be managed). Since the connection is dynamically switched, the load is not concentrated on some distribution servers, and the load is distributed to a plurality of distribution servers.
(2) A distribution server that is not operating due to a failure or the like is automatically excluded from connection targets, so that there is no waste of issuing a connection request to a distribution server where a client is not operating.
(3) When a distribution server that has not been operating starts operating, the client is automatically recognized as a connectable distribution server by issuing a notification to another distribution server. For this reason, the trouble at the time of distribution server addition is reduced.

  Hereinafter, an embodiment of a client server system to which the present invention is applied will be described.

  FIG. 1 shows a system configuration of a client server system according to an embodiment of the present invention. Reference numerals 101-1, 101-2, ..., 101-n denote distribution servers. Each distribution server includes a storage unit as indicated by 102-1, 102-2,..., 102-n. Here, a list of all clients connected to the present system and the operating status of all distribution servers. And a distribution server list indicating distribution information to be distributed to each client. Each distribution server communicates with other distribution servers at predetermined time intervals as indicated by arrows 105, and refers to and updates the distribution server list as needed from information obtained as a result of communication. Thereby, each distribution server grasps the operating status of all the distribution servers connected to this system, and holds it as a distribution server list. Communication between the distribution servers indicated by the arrow 105 may be performed using the network 104.

  Reference numerals 103-1, 103-2,..., 103-m denote clients connected to the system. Each client first sends a connection request to a predetermined distribution server when connecting to the system. The distribution server to which each client first connects is set in advance for each client. Once connected to the predetermined distribution server, there is an instruction to change the connection destination when the load on the distribution server is high (large), so the client distributes the connection destination according to the instruction from the distribution server. Switch servers. When a connection request is received from a client, each distribution server issues an instruction to change the connection destination to that client, if necessary, according to the load state of the server. That is, when the load of the server itself is high, the distribution server refers to the distribution server list to find a distribution server in a low (small) load state, and changes the connection destination to the distribution server to the client. Give instructions.

  FIG. 2 shows an example of contents stored in the distribution server list. “Server name” is the name of the distribution server connected to this system, “Destination” is the IP address of each distribution server, and “Maximum number of manageable clients” is based on the resource of the distribution server. It is a value that indicates the upper limit of clients that can perform These items are determined in advance for each server. However, the IP address may be determined dynamically, or the upper limit number of manageable clients may be separately set or changed dynamically. “Operating state” is a column for storing the current operating / stopped state of each distribution server. For a distribution server whose “operation status” is “operation”, the number of clients currently connected to the distribution server is stored in the “number of clients currently managed” column. The “currently managed number of clients” of the server whose “operating state” is “stopped” has no meaning, and therefore, “−” is shown in FIG.

  FIG. 3 is a flowchart of a client distribution server connection process. This process is executed at various timings such as when a distribution request (instruction to acquire distribution information from any distribution server) is performed on the client. In step 301, the client transmits a connection request to a distribution server that is preset to be connected first. Next, in step 302, a distribution information acquisition request is transmitted. In step 303, it is determined whether or not there is an instruction to change the connection destination from the distribution server. If there is no instruction to change the connection destination, the distribution information is acquired from the distribution server in step 306 and the connection with the distribution server is released in step 307. If there is an instruction to change the connection destination from the distribution server in step 303, the distribution server to be connected is changed to the instructed distribution server in step 304, and the currently connected distribution server (connection destination) in step 305 The connection with the distribution server that transmitted the change instruction) is released, and the process returns to step 301 to start the process again from the connection with the new distribution server. The client sets the acquired distribution information as setting information for controlling the operation of the client.

  FIG. 4 is a flow of distribution server list update processing of the distribution server. This processing is executed by each distribution server every predetermined time. In step 401, the operating status of other distribution servers (including “the number of clients currently managed”) is acquired. The acquired operating status is described in the “operating state” and “number of currently managed clients” fields of the distribution server list (FIG. 2) in the own distribution server. In step 402, it is determined whether the number of clients managed by the client has reached the upper limit. If the upper limit has been reached, in step 403, all other distribution servers are notified that their operating status and the number of managed clients have reached the upper limit. If the upper limit has not been reached, in step 404, the operation status of itself is notified to all other distribution servers. It should be noted that the other distribution servers that have received the notifications in steps 403 and 404, based on the notified information, “the number of clients currently managed” and “operating state” in the distribution server list in the own distribution server. ”Column is updated.

  The operation status acquisition in step 401 is performed by inquiring the operation status to all the distribution servers registered in the distribution server list described in FIG. When there is no response from the inquiry distribution server, it is assumed that the distribution server is stopped. When a new distribution server is connected to this system, the processing of FIG. 4 is executed in the distribution server, and the distribution server displays its own operating status (including the server name, connection destination, and the maximum number of clients that can be managed). All other distribution servers will be notified. When a distribution server receives a notification of operation status from another distribution server and the distribution server of the transmission source is not registered in the distribution server list, a new entry corresponding to the distribution server is added to the distribution server list. And set information such as operating status. Thereby, the newly connected distribution server can be managed by the distribution server list of each distribution server. The same applies when the distribution server that has been in a state in which communication is disabled becomes in a state in which communication is possible.

  In addition, the process of acquiring the operating status of the other distribution server in step 401 and updating the distribution server list, and the process of notifying the status of the own machine to the other distribution server in steps 402 to 404 are executed as separate tasks. You may make it do.

  FIG. 5 is a processing flow for a connection request from a client of the distribution server. This process is the process of the distribution server that has received the distribution information acquisition request sent from the client connected in steps 301 and 302 of FIG. In step 501, a connection request from the client (request in step 302) is received. In step 502, it is determined whether or not the number of clients currently managed by the local distribution server has reached the upper limit. If the upper limit has been reached, in step 503, the distribution server list is referenced to identify a distribution server with a low load at the present time. Next, in step 504, the connected client is instructed to identify a distribution server with a low load and reconnect to that server. This reconnection instruction is the connection destination change instruction described in step 303 of FIG. Next, in step 505, all other distribution servers are notified that the number of managed clients has reached the upper limit. Upon receiving this notification, the distribution server changes the “currently managed number of clients” column for the distribution server in the distribution server list in the own distribution server to an upper limit value.

  If the number of clients currently managed in step 502 has not reached the upper limit, in step 506, a connection request from the client is received. In this case, since the distribution information is transmitted to the client, the distribution information is acquired by the client in step 306 in FIG.

  In the distribution server connection process of the client in FIG. 3 described above, if the distribution server that is the first connection destination of the client is down (due to power-off or failure), connection cannot be made from the beginning. End up. Therefore, in order to avoid this, each client holds not only the first connection destination but also the addresses of the second, third,... Distribution servers to be connected next when the first connection destination cannot be connected. In addition, when it is not possible to connect to the first connection destination, it is preferable to try to connect to the second, third,.

  In the above-described embodiment, an example in which client setting information is distributed has been described. However, the present invention can also be applied to distribution of other information (for example, various contents of multimedia). However, the setting information of the client given as an example in the above embodiment is information for controlling the operation of the client, and it is very important to keep the latest setting information for each client in terms of security. According to the present invention, even if setting information to be distributed is changed and distribution requests from each client are intensively generated in a short time, the setting information can be quickly distributed to each client.

  In the embodiment described above, different setting information may be distributed for each client or each client type.

1 is a system configuration diagram showing an embodiment of the present invention. It is a figure which shows the outline of a delivery server list | wrist. It is a flow of a client distribution server connection process. It is a flow of the distribution server list update process of a distribution server. It is a processing flow for a connection request from a client of a distribution server.

Explanation of symbols

  101-1 to 101-n ... distribution server, 102-1 to 102-n ... storage means, 103-1 to 103-m ... client, 104 ... network.

Claims (1)

An information distribution system in which a plurality of clients and a plurality of distribution servers are connected to a network,
Each of the distribution servers is
Means for storing distribution information for distribution to the client;
Means for storing a distribution server list for storing connection destination addresses, operating states, and current load states for all distribution servers;
Means for determining whether or not the load status of the own machine has reached a predetermined load level when receiving the distribution information acquisition request transmitted from the client;
When the predetermined load level has been reached, a distribution server with a low load is identified by referring to the distribution server list, and the client that has transmitted the distribution information acquisition request is re-sent to the identified distribution server. Means for transmitting a connection destination change instruction for instructing connection, and notifying other distribution servers that the load status of the own device has reached the predetermined load level;
Means for receiving the distribution information acquisition request of the client and transmitting the distribution information to the client when the predetermined load level has not been reached;
Means for acquiring operating statuses of other distribution servers every predetermined time, and storing the acquired operating status in the distribution server list;
It is determined whether or not the load status of the own device has reached a predetermined load level every predetermined time, and if so, the other distribution server is notified that the load status of the own device has reached the predetermined load level. If it has not been reached, means to notify the other server of the operating status of its own machine,
When receiving a notification that the load status has reached a predetermined load level or a notification of the operation status from another distribution server, the information is set in an entry corresponding to the distribution server in the distribution server list. Means and
The client
Means for transmitting a distribution information acquisition request to the distribution server;
When there is an instruction to change the connection destination from the distribution server that is the transmission destination of the distribution information acquisition request, means for reconnecting to the instructed connection destination and transmitting the distribution information acquisition request;
An information distribution system comprising: means for receiving distribution information when the distribution information is transmitted from a distribution server that is a transmission destination of the distribution information acquisition request.

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