JPH0798682A - Client vs. server communication system - Google Patents

Abstract

PURPOSE:To attain communication with many clients while reducing the capacity of the table of a server side necessary for communication. CONSTITUTION:Communication equipments 9-1-9-n being the clients are divided into plural groups G1-Gm, and one communication equipment name g1-gm is applied to each group. A communication program 1-1 or the like of a communication equipment 10 being the server is provided with a table 2-1 having an entry corresponding to the group with which communication is operated by its own program by one to one, and the communication name g1-gm or various kinds of information necessary for communication are managed in the table. An address management table 6 holds the corresponding relation between the logical address and physical address of the communication equipment included in the group for each communication equipment name g1-gm, and has one management information storage area for each group. An address managing means 5 manages the address of the client by the table 6, and applies communicating capability with the server to the entire clients in the group while limiting the clients whose communication with the server can be attained in one period into one in one group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a client-to-server communication system, and in particular, divides a client into a plurality of groups and limits the number of clients that can communicate with a server at one time within one group to within the group. The client-to-server communication method that allows all the clients to communicate with the server.

[0002]

2. Description of the Related Art A plurality of communication devices (computers etc.)
In a communication network that is connected to each other through a network such as AN and communicates between communication devices using, for example, TCP / IP protocol, the following two types of addresses are used as addresses for identifying each communication device. Is used.

One is an address called a physical address, and for example, an Ethernet address corresponds to this. The other is an address called a logical address, for example, an IP address corresponds to this.

Further, in order for an application program operating on each communication device to identify a communication device as a communication partner, a kind of logical address called a communication device name is used.
It is defined separately from the IP address. This communication device name is unique in identifying a communication device as a communication partner only within the communication device in which the application program operates, whereas the IP address is unique in identifying each communication device in the entire network. Is different.

During communication between communication devices, the application program recognizes the communication partner device by the name of the communication device, and at the higher level of the TCP / IP protocol, the application program recognizes I.
Path selection or the like is executed by the P address, and the communication partner is specified by the Ethernet address at the lower level.

Therefore, a certain communication device A becomes a server,
When the plurality of communication devices B1 to Bn serve as clients and perform communication between the client and the server program on the server according to the request from the client, the client is included in the communication path establishment request from the client or the transmission data. Although the logical address and the physical address of the client are included, the communication device name of the client is not included.
It is necessary to hold and manage the correspondence relationship between types of addresses so that it is possible to recognize what kind of communication device having a logical address and physical address has what kind of communication device name. Further, in general, in order to communicate between communication devices, it is necessary to hold and manage various management information in addition to the above addresses, and a storage area for that purpose is required.

Therefore, conventionally, an entry for storing a communication device name of a client, a logical address, a physical address, and other management information in communication with the client is provided in a communication management subsystem that controls the communication function of the server. , The address management table provided for each client, and the server program of the server that communicates with the client has a communication partner information table provided with an entry for storing various management information in communication for each client. I am preparing.

[0008]

By the way, in a small-scale communication network, the number of clients with which the server communicates is small, so this does not pose a problem. However, in a large-scale communication network, the number of clients with which it communicates becomes large. The number becomes enormous, and accordingly, the capacity of the address management table required for the server side and the communication partner information table corresponding to each server program increases. Since these tables are constructed using the resources (memory and files) of the server, if the table capacity increases too much, the resources of the server will be squeezed and the operation of the server will be hindered. Therefore, a method for realizing communication with a large number of clients using a small capacity table is desired.

The present invention meets such a demand and is proposed based on the following idea.

The number of clients with which the server can communicate at one time is limited by other factors such as the processing capacity of the processor of the server and the line speed. Therefore, the storage area of the management information for each client is stored in the address management table of the server. However, even if an entry corresponding to each client is provided in the communication partner information table corresponding to each server program, not all are used at the same time. That is, there is no possibility of communicating with all of the clients that are communication partners at the same time. On the other hand, that does not mean that the number of clients to communicate with does not decrease, but it is necessary to enable communication with all clients.

Therefore, in the present invention, the clients are divided into a plurality of groups, and the number of clients that can communicate with the server at one time within one group is limited to one, while all the clients in the group can communicate with the server. The above-mentioned problems are solved by imparting sex. In this way, the address management table of the server need only have one area for storing various management information for each group, and there is also one communication partner information table for each server program for each group. You just have to have an entry.

[0012]

According to the client-to-server communication method of the present invention, a plurality of communication devices serving as clients and a communication device serving as a server connected to the plurality of communication devices via a network are used for communication. In the system, a communication device that serves as a server is divided into a plurality of communication devices that serve as clients, and the communication device names included in the group are set for each communication device name set for each group. The address management table having one management information storage area, which holds the correspondence between the logical address and the physical address, is provided for each server program running on the server, and is assigned to the group of clients with which the server program communicates. A communication partner information table having an area for holding various management information for each communication device name, By the serial address management table performs a client of address management, 1 in 1 group
The number of clients that can communicate with the server at one time is limited to one, and an address management unit that provides all clients in the group with the possibility of communicating with the server is provided.

[0013]

In the client-to-server communication system of the present invention, the address management table of the communication device serving as a server is set to one for each group when the plurality of communication devices serving as clients are divided into a plurality of groups. Each communication device name holds the correspondence relationship between the logical address and the physical address of the communication device included in the group, and also has one management information storage area, which corresponds to each server program running on the server. The communication partner information table has an area for holding various management information for each communication device name, and the address management means manages the address of the client by the address management table, and the address management means manages the server at one time within one group. 1 client that can communicate
Limit the number of clients to one and give all clients in the group the possibility to communicate with the server.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

Referring to FIG. 1, in an example of a communication network to which the present invention is applied, a communication device 10 as a server and a plurality of communication devices 9-1 to 9-n as clients are
Address resolution protocol (RPC) such as TCP / IP
Are connected by a network 8 using a communication protocol having

Communication devices 9-1 to 9- serving as clients
n is divided into a plurality of groups G1 to Gm, and communication device names g1 to gm are given to each of the groups G1 to Gm. In the example of the figure, three communication devices 9-1 to 9-3
Belongs to the group G1, the communication device name g1 is assigned, the two communication devices 9-4 and 9-5 belong to the group G2, the communication device name g2 is assigned, and one communication device 9 -N belongs to the group Gm and is given the communication device name gm.

The communication device 10 that serves as a server communicates with the communication devices 9-1 to 9-n that serves as clients to carry out some tasks as a server program.
-1 to 1-x and a communication management subsystem 3 that manages communication functions of all communication.

The communication program 1-1 has a communication partner information table 2-1. This communication partner information table 2-
1 is an entry 2-1-1 to 2-corresponding to a group of clients with which the communication program 1-1 communicates.
1-m. In the area 210 of each entry, the communication device name given to the client group as the communication partner is set, for example, when the system is generated. Further, the remaining area 211 is used as a storage area for various management information (for example, information on a buffer used for communication) necessary for communicating with the communication devices in the group. The other communication programs 1-2 to 1-x are also communication programs 1-1.
It has a communication partner information table similar to.

The communication management subsystem 3 has a communication program interface means 4, an address management means 5, an address management table 6 and a line control means 7.

The communication program interface means 4 is
It has an interface with the communication programs 1-1 to 1-x and controls data transfer.

The address management table 6 includes a communication device name g of each of the groups G1 to Gm of communication devices serving as clients.
The correspondence between the logical address and the physical address of the communication device included in the group is held for each 1 to gm, and 1
It is a table having one management information storage area.

2 to 4 show configuration examples of the address management table 6. As shown in FIG. 2, the address management table 6 is composed of a main table 60 and a sub table 61.

The main table 60 has entries 60-1 to 60-m equal to the number of groups of communication devices which are divided into clients, and each of the entries 60-1 to 60-6.
0-m is an area 600 for setting a communication device name, an area 601 for setting the number of communication devices 1, an area 602 for setting a pointer to an entry of the sub table 61, and other management information (for example, communication path establishment state, transmission Area 603 for setting the information of the buffer used for, the name of the communication program currently communicating with the client, etc.).

Further, the sub-table 61 has entries 61- which are equal in number to the communication devices 9-1 to 9-n which are clients.
1 to 61-n and each entry 61-1 to 61-n
Is composed of an area 610 for setting a pointer to an entry in the main table 60, an area 611 for setting a logical address, and an area 612 for setting a physical address.

For example, in the case of the client of the group G1 in FIG. 1, as shown in FIG. 3, one entry (for example, 60-1) for the group is allocated from the main table 60, and the sub table 61 stores the entry in the group. Three entries for each communication device 9-1 to 9-3 (for example, 61-1
~ 61-3) are assigned.

Then, the entry 60- of the main table 60-
1, the communication device name g1 set in the group G1 in the area 600 when the system is generated is
3 is set to 1 as the number of communication devices. Also, Area 6
A NULL value is initially set in 02, but during establishment of the communication path, a pointer pointing to an entry in the sub table 61 corresponding to the communication partner device is set as described later. Also, each entry 61-1 to 61 of the sub table 61
-3, a pointer to the entry 60-1 of the main table 60 related to the area 610 is set at the time of system generation, and the communication devices 9-1 to 9-1 to 611 are set in the area 611.
The logical address 9-3 is set. Furthermore, area 61
2 stores the physical addresses of the communication devices 9-1 to 9-3, which are appropriately obtained by the address resolution protocol.

When only one communication device 9-n is included in the group like the client of the group Gm in FIG. 1, one entry (for the group) from the main table 60 (see FIG. 4). For example, 60-m) is allocated, one entry (for example, 61-n) for the communication device 9-n in the group is allocated from the sub table 61, and the entry 60-1 of the main table 60 is allocated to the entry 60-1.
For example, when the system is created, the group Gm is added to the area 600.
The communication device name gm set in No. 1 is set in the area 601 as 1 as the number of communication devices, and the area 602 is set in the sub table 6
The pointer pointing to the entry 61-n in 0 is fixedly set together with the unrewritable instruction. For the entry 61-n of the sub table 61, for example, when the system is generated, the entry 6 of the main table 60 is stored in the area 610.
The pointer to 0-m is set, and the logical address of the communication device 9-n is set in the area 611. Furthermore, Area 6
In 12 is stored the physical address of the communication device 9-n, which is appropriately obtained by the address resolution protocol.

As shown in FIG. 1, in a communication network in which the communication devices 9-1 to 9-n which are clients are directly connected to the communication device 10 which is a server through the network 8, a sub-address management table 6 is used. Table 6
In the area 612 in No. 1, the communication devices 9-1 to 9-
Although the physical address of n is directly set, in the case of a communication network that is a composite of sub-networks in which a communication device that serves as a client is connected through an IP router, an IP that serves as an exit from the server to the client is included in area 612. The physical address of the router is set.

Referring again to FIG. 1, the address management means 5 manages the addresses of the clients by using the address management table 6 and limits the number of clients that can communicate with the server at one time within one group to the group. 5 to 8 are means for giving all the clients in the communication possibility to the server, and an example of the processing is shown in FIGS. Here, FIG. 5 shows a process when a communication path is requested, FIG. 6 shows a process when data is transmitted from a server, FIG. 7 shows a process when data is received from a client, and FIG. 8 shows a process when a communication path release request is made. Each processing is shown.

Further, the line control means 7 uses the TCP / IP protocol to communicate with the communication device 10 and the communication devices 9-1 to 9-n.
It is a means for controlling the line control required when communicating with the.

The operation of the present embodiment thus constructed will be described below.

Now, the communication device 10 and the communication devices 9-1 to 9-
Considering the initial state in which no communication path is established with n, in such a case, the state of the address management table 6 of the communication device 10 is in all areas 603 of the main table 60 of FIG. Information indicating that the communication path is not established is held, and a NULL value pointer is stored in the area 602 in the entry of the main table 60 corresponding to the group including two or more communication devices as shown in FIG. It is set.

In this state, for example, it is assumed that the communication device 9-1 belonging to the group G1 sends a communication path establishment request to the communication device 10 to the network 8. The communication path establishment request includes the logical address and physical address of the requesting communication device 10 as well as the logical address and physical address of its own device 9-1.

The above communication path establishment request is issued by the network 8
When it reaches the communication device 10 through and is received by the line control means 7, it is transmitted to the address management means 5, and the address management means 5 starts the processing shown in FIG.

First, an entry having a logical address and a physical address that match the logical address and the physical address of the communication device 9-1 included in the communication path establishment request is shown in the address management table 6 shown in FIG.
Search from (S1). By this search, the entry 61-1 shown in FIG. 3 is found (NO in S2).
If there is no corresponding entry (Y in S2)
S), error processing is executed (S3).

Next, the entry 60-1 in FIG. 3 of the main table 60 pointed by the pointer of the area 610 of the found entry 61-1 is acquired (S4).
Then, based on the management information in the area 603 of this entry 60-1, it is determined whether or not the communication path is being established (S
5). Then, if the communication path is not established (N in S5)
O), the pointer to the corresponding entry 61-1 of the sub table 60 is set in the area 602 (S6), and the entry 60-1 and the entry 61-1 are associated as shown by the broken line in FIG. However, as shown in FIG. 4, in the case of a group including only one communication device, since the pointer from the main table to the sub table is fixedly set, the setting of the pointer is omitted.

Then, a communication path is established between the communication device 9-1 that has made the communication path establishment request and the communication management subsystem 3 (S7). At this time, necessary management information such as that the communication path is established is set in the area 603 of the entry 60-1.

On the other hand, if it is determined in step S5 that the communication path is already being established, the error processing of step S3 is performed and the request for establishing the communication path is rejected. Therefore, if another communication device 9-2 or 9-3 in the same group G1 issues a communication path establishment request after the communication path is established with the communication device 9-1, it is rejected. It will be.

Next, the operation of transmitting / receiving data between the communication device 9-1 having the communication path established as described above and the communication program (for example, 1-1) of the communication device 10 will be described. .

The communication program 1-1 is the communication device name g1.
When transmitting data to another communication device, the communication device name g1 of the communication device to which the data is to be transmitted is entered in the internal communication partner information table 2-1 (for example, 2-1.
1) and sends it to the address management means 5 via the communication program interface means 4 together with the transmission data.
The communication program 1-1 is not aware of which communication device in the group G1 the communication device name g1 is. When the data is transmitted with the communication device name g1, which communication device actually receives the data is determined by which communication device in the group G1 the communication path is currently established with.

The address management means 5 is the communication program 1
When the communication device name g1 and the transmission data are received from -1, the processing shown in FIG. 6 is started.

First, the main table 60 shown in FIG. 2 of the address management table 6 is searched by the received communication device name g1 (S11). This results in entry 60-
One can be found.

Next, the entry of the sub table 61 pointed by the pointer set in the area 602 of the found entry 60-1 is acquired (S1).
2). As a result, the entry 61-1 in FIG. 3 is acquired.

Area 6 of this entry 61-1
The logical address of the communication device 9-1 set to 11 and the physical address of the communication device 9-1 set to the area 612 are acquired, and the transmission data is notified to the line control means 7 to request transmission. (S13).

The line control means 7 transmits the transmission data to the communication device 9-1 through the network 8 according to the notified logical address and physical address based on the TCP / IP protocol, and the communication device 9-1 receives this. To do.

The same applies to the case of transmitting data from the other communication programs 1-2 to 1-x to the communication devices of the group G1.

On the other hand, the communication device 9-1 has a certain communication program (for example, 1-
When transmitting data to 1), in addition to the logical address and physical address of the communication device 10, information for identifying the communication program 1-1 as the destination, transmission data including the logical address and physical address of the own device 9-1 are transmitted. Network 8
Send to.

When the above transmission data reaches the communication device 10 through the network 8 and is received by the line control means 7,
It is transmitted to the address management means 5, and the address management means 5 starts the processing shown in FIG.

First, the communication device 9- included in the received data
An entry having a logical address and a physical address matching the logical address and the physical address of 1 is searched from the sub table 61 shown in FIG. 2 in the address management table 6 (S21). By this search, the entry 61-1 shown in FIG. 3 is found (NO in S22). If there is no corresponding entry (YES in S22)
S), error processing is executed (S23).

Next, the entry 60-1 of FIG. 3 of the main table 60 pointed by the pointer of the area 610 of the found entry 61-1 is acquired (S2).
4). Then, based on the management information in the area 603 of this entry 60-1, it is determined whether or not the communication path is being established (S25). If the communication path is being established (S25
YES), the communication device name g1 of the group G1 set in the area 600 in the entry 60-1 is notified to the communication program 1-1 of the connection destination specified by the communication path establishment request together with the received data ( S26). If the communication path is not established, error processing is performed (S23).

The communication device 9-1 communicates with other communication programs 1-2 to 1-x of the communication device 10 in the same manner as above.

Now, when the communication device 9-1 completes the transmission / reception of the necessary data and, for example, a communication path release request is issued from the communication device 9-1, the following processing is performed. The communication path release request issued from the communication device 9-1 includes the logical address and the physical address of the communication device 9-1.

The above communication path release request is issued by the network 8
When it reaches the communication device 10 through and is received by the line control means 7, it is transmitted to the address management means 5, and the address management means 5 starts the processing shown in FIG.

First, the sub-table 61 shown in FIG. 2 in the address management table 6 has an entry having a logical address and a physical address that match the logical address and the physical address of the communication device 9-1 included in the communication path release request.
Is searched from (S31). By this search, the entry 61-1 shown in FIG. 3 can be found (N in S32).
O). In addition, when the corresponding entry does not exist (S3
If YES, the error process is executed (S33).

Next, the entry 60-1 of FIG. 3 of the main table 60 pointed by the pointer of the area 610 of the found entry 61-1 is acquired (S3).
4). Then, based on the management information in the area 603 of this entry 60-1, it is determined whether or not the communication path is being established (S35). Then, if the communication path is being established (S35)
If YES, the pointer of the area 602 is set to NULL (S36). However, as shown in FIG. 4, in the case of a group including only one communication device, the pointer is not changed.

Then, the communication path between the communication device 9-1 that requested the communication path release and the communication management subsystem 3 is released (S37). At this time, management information indicating that the communication path is not established is set in the area 603 of the entry 60-1.

On the other hand, if it is determined in step S35 that the communication path has already been released, the error processing of step S33 is performed and the communication path release request is rejected.

The above processing for releasing the communication path is performed when the client requests the release of the communication path. However, it is also possible to issue a request for releasing the communication path from the server, and in that case as well. Is performed.

The processing at the time of communication between the client and the server according to the present embodiment has been described above by taking the communication device 9-1 as an example. However, other communication devices 9-2 and 9-3 in the same group G1 are described.
The same operation is performed during communication with the communication devices in the other groups G2 to Gm. However, as described above, the number of communication devices that can communicate with the communication device 10 serving as a server at one time is limited to one in one group.

[0060]

As described above, according to the present invention, the client is divided into a plurality of groups, one management information storage area is provided for each group in the address management table of the server, and communication corresponding to each server program is provided. Since one entry is provided for each group in the partner information table, the number of clients that can communicate with the server at one time within one group is limited, but using a table with a small capacity, All clients in the group can be given the possibility of communicating with the server. Therefore, without putting pressure on server resources (memory and files),
It is possible to substantially increase the number of clients that can substantially communicate.

For example, one area (60 in FIG. 2) for storing various management information in the address management table.
The size of 3) and the size of one entry of the communication partner information table of each server program are both set to, for example, 256.
Bytes are required, and if 100 clients can communicate with each server program, for example, if the clients are divided into 10 groups, it will be about 25
Server resources (memory and files) can be saved by 6 bytes x 90 x number of server programs.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a communication network to which the present invention is applied.

FIG. 2 is a diagram showing a configuration example of a main table and a sub table that form an address management table.

FIG. 3 is a diagram showing an example of contents of entries of a main table and a sub table assigned to a client group including a plurality of communication devices.

FIG. 4 is a diagram showing an example of contents of entries of a main table and a sub table assigned to a client group including one communication device.

FIG. 5 is a flowchart showing a processing example when a request for establishing a communication path is made by the address management means.

FIG. 6 is a flowchart showing an example of processing performed by the address management means when transmitting data.

FIG. 7 is a flow chart showing an example of processing when the address management means receives data.

FIG. 8 is a flowchart showing an example of processing when a communication path release request is made by the address management means.

[Explanation of symbols]

1-1 to 1-x ... Communication program serving as server program 2-1 ... Communication partner information table 210 ... Area for setting communication partner name 211 ... Area for setting various management information 3 ... Communication management subsystem 4 ... Communication Program interface means 5 ... Address management means 6 ... Address management table 7 ... Line control means 8 ... Network 9-1 to 9-n ... Communication device serving as client 10 ... Communication device serving as server G1 to Gm ... Group g1 to gm … Communication device name

Claims (5)

[Claims] 1. A plurality of communication devices serving as clients,
In the method of communicating between the plurality of communication devices and the communication device serving as the server connected through the network, the communication device serving as the server is divided into a plurality of groups when the plurality of communication devices serving as the clients are divided into a plurality of groups. The correspondence relationship between the logical address and the physical address of the communication devices included in the group is held for each communication device name set for each group, and
An address management table having one management information storage area, and provided for each server program running on the server,
The communication partner information table having an area for holding various management information for each communication device name given to the group of clients with which the server program communicates, and the address management table manage the address of the client. A client-to-server communication system comprising: an address management unit that gives all clients in a group the possibility of communicating with the server while limiting the number of clients that can communicate with the server at one time. 2. The address management table is composed of a main table having the same number of entries as the number of groups of the client and a sub-table having the same number of entries as the number of communication devices serving as the clients. The sub-table entries that are associated one-to-one with the communication devices to which they belong hold the correspondence between logical addresses and physical addresses, and the entries in the main table that are associated one-to-one with each group It has an area for holding the set communication device name and for holding the various management information, and mutually exchanges the entry of the main table corresponding to each group and the entry of the sub table corresponding to the communication device belonging to the group. Provide associated pointer areas for the primary and secondary table entries, and point the secondary table entries In the pointer area, a pointer that points to the entry of the corresponding main table is fixedly held, and in the pointer area of the entry of the main table that corresponds to a group that includes only one communication device, the pointer that points to the sub-table that corresponds to that communication device The pointer area of the entry of the main table corresponding to the group including a plurality of communication devices is dynamically stored in the pointer area of the entry of the sub table corresponding to the communication device whose communication path is being established. The client-server communication system according to claim 1, wherein the client-server communication system has a configuration for storing. 3. The address management means, when a communication path establishment request including a logical address and a physical address of the communication device from a communication device serving as a client is requested, an entry of a sub-table including the requested logical address and physical address. Is searched for, the corresponding entry of the main table is acquired according to the pointer set in the pointer area of the searched entry, and based on the contents of the area holding the various management information of the acquired entry of the main table, Check whether or not the communication path is being established with any communication device in the group, and on condition that the communication path is not being established, between the communication device that has made the communication path request and the communication device that will be the server. 3. The client-to-server communication system according to claim 2, wherein a communication path is established in the. 4. The address management means, when a data transmission request is made from the server program specifying a communication device name, searches an entry in the main table including the communication device name being requested, and a pointer area of the searched entry. The corresponding sub-table entry is acquired according to the pointer set in the table, and the logical address and physical address held in the acquired sub-table entry are notified to the line control means together with the transmission data to request the data transmission. 4. The client-to-server communication system according to claim 3. 5. The address management means, when receiving transmission data including a logical address and a physical address of the communication device from the communication device serving as the client, stores an entry of a sub table including the received logical address and physical address. The main program is searched, the corresponding entry in the main table is acquired according to the pointer set in the pointer area of the searched entry, and the received data together with the communication device name set in the acquired entry in the main table is stored in the server program. The client-to-server communication system according to claim 4, wherein the notification is made.