JPH11167550A - Client server system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a client server system where plural clients can effectively operate a network for plural servers in a simple constitution. SOLUTION: When the power supply is applied to a client 1, an operating system starts and also the states of servers 1 and 2 connected to a server management part 5a are acquired. The server 2 and 3 are connected to four clients and one client respectively and accordingly the client 1 is connected to the server 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a client server system, and more particularly, to a client server system that determines a server to which a client connects.

[0002]

2. Description of the Related Art Conventionally, a client server system of this type is known as shown in FIG. In the figure, the clients 901 a to 901 c and the clients 901 a to 901 c are connected via a network 910.
Servers 902a to 902c connected to the server, server connection units 904a to 904c that are internal circuits of the clients 901a to 901c, and the servers 902a to 902.
client connection units 905a to 905 which are internal circuits
5c and the clients 901a to 901 shown in FIG.
server connection destination data 903a to 903a, which are internal data of the server c and store the server to be connected when connecting to the server.
03c. Note that the server connection destination data 903a to 903c include the servers 902a to 902c.
2c is set with priority.

In the above configuration, the client 90
When the server connection destination data of 1a is set as shown in FIG. 11, the server connection unit 904a first selects the first-ranked server 902a and connects to the client connection unit 905a, The client 901a and the server 902a are connected. Here, when the server 902a is stopped, the server connection unit 904a selects the server 902b in the second order and connects to the client connection unit 905b, so that the client 902
1a is connected to the server 902b.

Further, when the server 902b is stopped, the server connection unit 904a selects the third-ranked server 902c and connects to the client connection unit 905c to connect with the client 901a. The server 902c is connected. Note that the clients 901b and 901c also determine the server to be connected by the same operation from among the servers 902a to 902c.

[0005]

In the above-described conventional client-server system, depending on the setting of the server connection destination in the client, client connections are concentrated on a specific server, the load on the server increases, and the response to the client decreases. There was a problem to do.

The present invention has been made in view of the above problems, and has as its object to provide a client server system in which a plurality of clients can efficiently operate a network with a simple configuration in a plurality of servers.

[0007]

According to one aspect of the present invention, there is provided a client-server system comprising a plurality of clients and a plurality of servers connected via a network and capable of bidirectional communication. In the above, the client, the first server state management means to obtain the state of the server and the number of client connections of the server in a fixed period, and the first to store the data obtained by the first server state management means A server status storage unit, based on the status of the server obtained by the first server status management unit, selecting a server having a small number of connections with the client from a plurality of servers, and connecting the selected server to the client; Means for selecting the server, and the server selects a state of the server and a connected client. Second server state management means for managing the number of clients, second server state storage means for storing data managed by the second state management means, and a connection request when receiving a connection request from the client. And a client connection means for connecting to the output client.

[0008] In the invention according to claim 1 configured as described above, the first server status management means transmits the data from the second server status storage means via the second server status management means at regular intervals. The status of the server and the number of connected clients are acquired and stored in the first server status storage means. Here, the server selection means selects a server with a small number of client connections while the server is running from the state of the server stored in the first server state storage means, and connects to the client connection means. Output the request. If the output destination server of the connection request is connectable, the server that is currently connected is disconnected and connected to the selected server. The latest status of the server can be ascertained by acquiring the status of the server at regular intervals. As another example of the timing at which the client acquires the status of the server, the invention according to claim 2 is characterized in that the first server status management means accesses the server when the first server status management means accesses the server. Is configured to acquire the number of client connections.

In the invention according to claim 2 configured as described above, the first server status management means acquires the status of the server when the client accesses the server, Obtain the number of client connections in the server and check the latest status of the server.

[0010] Further, the server becomes inactive when the shutdown processing is performed, and the client connected to the server recognizes that the server has been stopped if the client does not perform access for a fixed period. Can not do it. According to a third aspect of the present invention, in the client server system according to any one of the first and second aspects, the second server state management means executes a shutdown process in the server. In the case, the status of the server is stopped with respect to the first server status management means of the other clients connected via a network and the second server status management means of the server. It is configured to notify.

In the invention according to claim 3 configured as described above, the second server status management means detects, when the server of the second server status management means performs a shutdown process. At the same time, it notifies the first server status management means of the other client or the second server status management means of the other server. The first server status management unit of the other client or the second server status management unit of the other server that has received the notification performs the shutdown processing in the first and second server status storage units. Stop the server that has failed.

By the way, the time when the server goes down is the time when the server itself performs the shutdown processing as described above. However, a server failure may occur without normal shutdown processing due to an abnormality in hardware or software. In this case, since the client that first accesses the server that has gone down can detect the down, it is necessary to notify this to the other clients and the server. As an example of the configuration of the first server status management means that performs this notification, the invention according to claim 4 is as follows.
In the client server system according to any one of claims 1 to 3, the first server status management means accesses the connected server and detects that the server is down. In this case, the status of the server has been stopped with respect to the first server status management unit of the other client connected via a network and the second server status management unit of the server. Is notified.

[0013] In the invention according to claim 4 configured as described above, the first server state management means goes down when the connected server accesses the server and there is no response. Detect that Then, the server in the first server storage unit is stopped, and the server is stopped in the first server state management unit and the second server state management unit of the other connected clients and servers. Notify that the status has been reached. The first server status management unit of the other client that has received the notification stops the server in the first server status storage unit. Further, the second server status management means of the other server stops the same server of the second server status storage means.

Further, according to a fifth aspect of the present invention, in the client server system according to any one of the first to fourth aspects, the server status management means comprises:
In the server connection flag which is set to a flag when connected to the server provided in the server selecting means, if the flag is set, the connection of the connected server is obtained even if the server having a small number of client connections is acquired. There is a configuration that does not change the destination.

[0015] In the invention according to claim 5 configured as described above, when the client starts up such as power-on, the first server state management means connects to a server with a small number of acquired connections. When the connection is completed, the server connection flag is set. When the flag is set, the first server status management means acquires the status of the server and the number of connections of the client, and even if a server with a small number of connections is detected, the connection of the server once connected is not canceled. .

In the method according to the fifth aspect, when the server once connected is stopped due to a failure or the like and then recovered and returned to the normal state, the same recovery is performed without restarting the client. Unable to reconnect to server. According to a sixth aspect of the present invention, in the client server system according to the fifth aspect, the first server state management means stores the name of the connected server when the connection destination server goes down. It is stored in one server status storage means, the connection destination is switched, and when the downed server recovers, it is reconnected to the same server.

In the invention according to claim 6 configured as described above, when the first server status management means detects that the connected server has gone down, the first server status management means stores the name of the downed server in the server status storage. Store in the means and switch the connection destination. Here, when the downed server recovers and returns to the system normally, the first server state management means reconnects to the recovered server. That is, it is possible to automatically reconnect to the restored server.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a client server system according to the first embodiment of the present invention. In FIG. 1, a client-server system is constructed by a client 1 such as an end-user terminal, a server 2 and a server 3 that perform actual business processing and the like, and a network 4. The client 1 includes a server status management unit 5a that manages the status of a server, a server status table 5b in which the server status management unit 5a stores a server status, and a server that selects a connection destination server based on the server status table. Selection unit 5c and the same server selection unit 5c
Server connection unit 5 that physically connects to the server selected by
d. The server 2 includes a server status management unit 6a that manages the status of the server, a server status notification unit 6b that notifies the server status management unit 5a of the server status, and a connection destination server based on the server status table. And a client connection unit 6d for connecting to the server selection unit 6c. Further, the server 3 includes a server status management unit 7a for managing the status of the server and the server status management unit 5a.
A server status notifying unit 7b for notifying the server status to the server, a server selecting unit 7c for selecting a connection destination server based on the server status table, and a client connecting unit 7d for connecting to the server selecting unit 5c. You.

FIG. 2 is a flowchart showing a process of connecting the client 1 to one of the servers 2 and 3. FIG. 3 shows the contents of the server status table 5b. The server status management unit 5
As for a, measurement is performed for a certain period of time in order to acquire the states of the servers 2 and 3 at a certain period (step S100). When a certain period of time has passed, the server status notification units 6c and 7c
From the server 2 and 3 (step S1)
05) and stored in the server status table 5b. At this time, the server status table 5b stores the server name, the start / stop status, and the number of client connections as shown in FIG. Here, the server selection unit 5c
Searches for a server with a small number of client connections from the server status table (step S115), and selects the server 3 with a small number of connections (step S12).
0). Then, the server connection unit 5c outputs a connection request and executes connection to the selected server 3 (step S125).

If the number of client connections is equal in all the servers in step S115, and if there is no connection due to power-on or the like (step S130), the upper level of the server status table 5b is set. The server is connected to the server (step S135). If the server is already connected, the connection is maintained. Of course, in the server status management unit 5a,
Down servers are not eligible for selection.

At this time, the process of connecting the server 3 to the client 1 is shown in the flowchart of FIG. The client connection unit 7d determines a connection request from the client 1 (step S15).
0), if there is no connection request, the server status notification unit 7
c determines whether there is a status read request from the client 1 (step S155). If there is a read request, the server status management unit 7a reads the status of the own server from the server status table 7b (step S160), and sends the server status management unit 5a of the client 1 from the status notification unit 7c. (Step S165).

In step S150, when there is a connection request from the client 1, the client connection unit 7d connects to the server connection unit 5d (step S170) and the server state management unit 7a. Increments the number of client connections (step S175) and updates the server status table 7b (step S180).

Next, the operation of this embodiment configured as described above will be described. When the power of the client 1 is turned on, the operating system starts up, and the server status management unit 5a acquires the status of the server from the connected servers 2 and 3 (step S1).
00 to S110). In the case of the present embodiment, the number of client connections of the server 2 is 4, and the number of client connections of the server 3 is 1, so that the client 1 connects to the server 3 (steps S115 to S12).
5).

As described above, after a fixed time (step S105), the server status is acquired (step S1).
05) Therefore, the client 1 can always grasp the latest server status, check the number of client connections of the servers 2 and 3 during this fixed time, and connect to a server having a small number of connections. Therefore, the number of client connections of the servers 2 and 3 can be equalized.

Next, a client server system according to a second embodiment of the present invention will be described with reference to the block diagram of FIG. In the figure, a client-server system is constructed by a client 10 such as an end-user terminal, a server 20 and a server 30 that perform actual business processing, and a network 40.

The client 10 includes a server status management unit 50a for managing server status, and a server status table 5 for storing the server status by the server status management unit 50a.
0b, a server selection unit 50c for selecting a connection destination server based on the server status table, and the server selection unit 5
A server connection unit 50d that physically connects to the server selected by the server 0c, and a server connection flag 50e that becomes “1” when the server selection unit 50c connects to the server.

Further, the server 20 is based on a server status management unit 60a for managing the status of the server, a server status notification unit 60b for notifying the server status management unit 50a of the status of the server, and the server status table. It comprises a server selection unit 60c for selecting a connection destination server, and a client connection unit 60d for connecting to the server selection unit 60c.

Further, the server 30 is based on a server status management unit 70a for managing server status, a server status notification unit 70b for notifying the server status management unit 50a of the server status, and a server status table. It comprises a server selection unit 70c for selecting a connection destination server, and a client connection unit 70d for connecting to the server selection unit 50c.

FIG. 6 is a flowchart showing the processing contents when the client 10 uses the server connection flag. The server status management unit 50a includes:
A certain period of time is measured in order to acquire the states of the servers 20 and 30 at a certain period (step S200). When a certain period of time has passed, the server status notification units 60c, 70
c, the statuses of the servers 20 and 30 are acquired (step S205) and stored in the server status table 50b. At this time, the server status table 50b
Stores a server name, a start / stop state, and the number of client connections as shown in FIG.

Next, the content of the server connection flag 50e is determined (step S211). If "1", the server is already connected to any one of the servers, so that the connection destination server is newly switched. Absent. The server connection flag 50
If e is not "1", the server selecting unit 50c searches the server status table for a server with a small number of client connections (step S215), and selects the server 30 with a small number of connections (step S220). . Then, the server connection unit 50c outputs a connection request and executes connection to the selected server 30 (step S225).

If it is determined in step S215 that the number of client connections is equal in all servers and that no server is connected at any time due to power-on (step S230), the server status table 50b
(Step S235), and if the server has already been connected, the connection is maintained as it is. Here, in steps S225 and S235, when a new connection is made with the server, the server status management unit 50a sets the server connection flag 50e.
Is set to "1" (step S240).

Next, the operation of this embodiment configured as described above will be described. When the power of the client 10 is turned on, the operating system starts up, and the server status management unit 50a acquires the status of the server from the connected servers 20, 30 (steps S205 to S215). In the case of the present embodiment, since the number of client connections of the server 2 is four and the number of client connections of the server 3 is one, the client 1 connects to the server 3 (steps S210 to S210).
225). When this connection is completed, the server connection flag 5
0e becomes "1" (step S240), and thereafter, in step S211, the server connection flag 50e is checked.

As described above, when the client 1 first connects to the server, the client connection flag 5
0e is set to “1” (step S240). Thereafter, in step S211, the same server connection flag 50e is checked, and if “1”, that is, if any server has already been connected, a new It is no longer necessary to change the connection destination.

Next, a client server system according to a third embodiment of the present invention will be described with reference to the block diagram of FIG. In FIG. 1, a client 100 such as an end-user terminal and a server 20 that performs actual business processing and the like
0, a client server system is constructed by the server 300 and the network 400.

The client 100 includes a server status management unit 500a for managing server status, a server status table 500b for storing the server status by the server status management unit 500a, and a connection destination server based on the server status table. A server selection unit 500c to be selected, a server connection unit 500d for physically connecting to the server selected by the server selection unit 500c, and the server selection unit 500c
Server connection flag 500e that is set to "1" when the server is connected to the server, and the server down flag that stores the name of the connected server and the server down flag to "1" when the connection destination server goes down. And a table 500f.

The server 200 includes a server status management unit 600a for managing server status, a server status notification unit 500b for notifying the server status management unit 500a of the server status, and a server status table. It comprises a server selection unit 500c for selecting a connection destination server, and a client connection unit 600d for connecting to the server selection unit 500c.

Further, the server 300 includes a server status management unit 700a for managing the status of the server, a server status notification unit 700b for notifying the server status management unit 500a of the status of the server, and a server status table. It comprises a server selection section 700c for selecting a connection destination server, and a client connection section 700d for connecting to the server selection section 500c.

FIG. 9 is a flowchart showing processing contents including the case where the server 3 to which the client 1 is connected goes down during connection. FIG. 8 shows the contents of the server down table 500f.
The server state management unit 500a measures a certain period of time to acquire the states of the servers 200 and 300 at a certain period (step S300). When a certain period of time has elapsed, the statuses of the servers 200 and 300 are acquired from the server status notification units 600c and 700c, and the server status table 500b is updated (step S30).
5 to S310). At this time, the connected server 3
00 is detected (step S3
20), the name of the server 300 is as shown in FIG.
It is stored in the server down table 500f (step S325), and the server down flag is set to "1" (step S330).

Next, the server connection flag 500e is returned to "0" (step S335), and step S37 is performed.
By moving to 0, a new server is connected. In the present embodiment, the connection is made to the server 200 (steps S370 to S395). Here, before the server 300 that has gone down is recovered, the server down flag of the server down table 500f is “1”, so that the process branches to step S350 in step S340.
It is determined whether or not the server 300 stored in the server down table is running by referring to the server status table (step S35).
5) If the server 300 has recovered, connect to the recovered server 300 and set the server down flag to "0" (steps S360 to S36).
1).

Next, the operation of this embodiment configured as described above will be described. When the client 100 is already connected to the server 300, the server 30
When 0 is down (step S320), the server 300 is stored (step S325), and the connection to the server 200 is switched (steps S365 to S39).
5). Here, when the server 300 is repaired and connected to the network, it is detected (step S3).
05 to S310), the connection is switched to the server 300 (steps S350 to S361).

As described above, the server 300 goes down, and the client 1 connects to the server 200. Here, when the server 300 is restored and connected to the network, the client 1 that was connected to the server 300 immediately before the server went down is automatically connected to the server 300. Just by connecting to the network, the system can be restored.

[0042]

As described above, the present invention can provide a client-server system capable of connecting to a plurality of servers equally, reducing the load on the servers, and improving the response of the entire system. . According to the second aspect of the present invention, the status of the server can be acquired at the timing when the client requests the server for processing, so that the server can be used efficiently.

According to the third aspect of the present invention,
If the server has a shutdown process, the entire system can recognize the shutdown process, and the client connected to the server can immediately change the connection destination.
Further, according to the invention according to claim 4, the client which detects the down due to the server shutdown processing first notifies the whole system, so that the client connected to the server can immediately change the connection destination. Can be changed.

Further, according to the fifth aspect of the present invention,
Since the server once connected is not changed, the state of the system can be clearly grasped. Furthermore, according to the invention according to claim 6, the client connected to the restored server immediately before the downtime can be automatically reconnected, so that the system can be easily restored.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a client server system according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating processing for connecting a client to a server according to the first embodiment.

FIG. 3 shows a server status table in the first embodiment.

FIG. 4 is a flowchart illustrating processing for connecting a server to a client in the first embodiment.

FIG. 5 is a block diagram showing a configuration of a client server system according to a second embodiment of the present embodiment.

FIG. 6 is a flowchart illustrating processing contents when a client uses a server connection flag in the second embodiment.

FIG. 7 is a block diagram showing a configuration of a client server system in a third embodiment of the present embodiment.

FIG. 8 shows a server down table in the third embodiment.

FIG. 9 is a flowchart illustrating processing for automatically connecting to a restored server after a client goes down in the third embodiment.

FIG. 10 is a block diagram showing a configuration of a conventional client server system.

FIG. 11 shows a server connection destination table in a conventional client server system.

[Explanation of symbols]

 Reference Signs List 1 client 2 server 3 server 4 network 5a server state management unit 5b server state table 5c server selection unit 5d server connection unit 6a server state management unit 6b server state table 6c server state notification unit 6d client connection unit 7a server state management unit 7b server Status table 7c Server status notification unit 7d Client connection unit

Claims (6)

[Claims] 1. A client-server system comprising a plurality of clients and a plurality of servers which are connected via a network and are capable of bidirectional communication, wherein the clients are arranged such that the state of the server and the number of client connections of the server are periodically performed. A first server status management unit that acquires the first server status management unit, a first server status storage unit that stores data acquired by the first server status management unit, and a first server status management unit that acquires the first server status management unit. A server selecting means for selecting a server having a small number of connections with the client from a plurality of servers based on a state and connecting the selected server to the client; and Second server status management means for managing the number of clients that have A second server status storage unit for storing data managed by the unit; and a client connection unit for connecting to the client that has output the connection request when receiving the connection request from the client. Server system. 2. The client server system according to claim 1, wherein the first server status management means acquires a status of the server and a number of client connections in the server when accessing the server. A client-server system, characterized in that: 3. The client server system according to claim 1, wherein said second server status management means is connected to a network via a network when shutdown processing is executed in said server. Notifying the first server status management means of the other client and the second server status management means of the server that the server has been stopped by the other connected clients Client server system. 4. The client server system according to claim 1, wherein the first server status management means accesses the connected server, and the server goes down. The server status is stopped for the first server status management means of the other clients connected via the network and the second server status management means of the server A client-server system for notifying that the server has become a server. 5. The client-server system according to claim 1, wherein the server status management unit includes a server connection flag that sets a flag when the server selection unit connects to the server. If the flag is set, the client server system does not change the connection destination of the connected server even if the server with a small number of client connections is acquired. 6. The client server system according to claim 5, wherein the first server status management means is configured to execute the first server status management means when the connection destination server goes down with the server connection flag set. A client server system for switching the connection destination server in the server selection means and reconnecting to the same server when the downed server is restored.