JPH07302237A - Server-client type system - Google Patents

Abstract

PURPOSE:To cope with network multiplexing, to construct a process for processing data or the like regardless of a communication route or the like, to independently construct the process for selecting a communication line corresponding to the conditions of the communication route and to respectively independently perform design, development, production and testing, etc. CONSTITUTION:When a data processing is requested from the client process 4 of a client machine 2, a pseudo client process 11 selects a LAN 5 or the LAN 6 and the communication line of the pseudo server process 10 of a server machine 1 and the communication route 7 or 8 is established. A server process 3 accesses a data base 9 and performs a prescribed data processing based on data requested contents. When the communication line is abnormal, the other communication route 7 or 8 is selected and the data processing is executed. Thus, without changing the existing DBMS of a server-client type and the application of a window system, this system is constructed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a server / client type system on a network, which is a DBM.
S (Data Base Management Sy)
It is applied to the system).

[0002]

2. Description of the Related Art FIG. 12 is a diagram showing the structure of a server-client type system. 1 is a server machine, 2-1 and 2
-4 is a client machine, and 5 is a local area network (LAN) connecting the server machine 1 and the client machines 2-1 to 2-4. In response to the requests from the client machines 2-1 to 2-4, the server machine 1 accesses the database 9 and processes the data. When the system is important and reliable, a dual local area network is usually used.

FIG. 13 shows a server / client type DBMS (DataBase Manager) on a duplicated LAN.
In the configuration diagram of the (Iment System), an example in which the server machine 1 and the client machine 2 have a one-to-one correspondence is shown. In the figure, 1 is a server machine, 2 is a client machine, 3 is a DBMS server process resident in the server machine 1, and 4 is a client process on the client machine 2. Reference numerals 5 and 6 are LANs, and 9 is a database accessed by the DBMS server process 3.

A service request (request) issued from the client process 4 to the DBMS server process 3 and a response (reply) from the DBMS server process 3 to this request are sent via the physical networks LAN5 and LAN6. Be seen. In the figure, the routes are route 7 and route 8, respectively.

FIG. 14 shows the hardware configuration of the server machine 1, and FIG. 15 shows the hardware configuration of the client machine 2. In the figure, interface cards 1a, 1b and 2a, 2b in the input / output circuit are duplicated and connected to LAN5 and LAN6, respectively. Predetermined programs such as a DBMS server process and a client process are stored in the memory.

FIG. 16 is a software configuration diagram of a conventional server / client type DBMS constructed on a duplex LAN. 3 is a DBMS server process, 4 is a client process, and 9 is a database accessed by the DBMS server process 3. 12 is the LAN 5 and L in FIG.
It is a network corresponding to AN6. The client process 4 is composed of three parts, 13, 14, and 15. 13 is an application program, 14 is D
It is a DBMS library that issues a request to the BMS server process 3 and has a program interface with the application program 13. Reference numeral 15 is a route selection logic for selecting either the route 7 or the route 8 in FIG.

Next, the operation will be described. In FIG. 16, the application program 13 in the client process 4 uses the DBMS library 14
Data request (inserter) to the S server process
t, delete, update ... LAN
In the conventional implementation method corresponding to the duplication of the above, the route selection logic 15 is incorporated in the client process 4,
By changing the location of the server process to the S library 14 in a pseudo manner, the change of the route when the one-sided LAN fails is realized. An example of this route selection logic 15 is shown in the example of the duplicate LAN compatible route selection algorithm of FIG.

When the request from the client to the DBMS server is rejected via the route 7, the algorithm of FIG. 3 is switched to the route 8 to make the request again, and when this request is rejected, the client machine Determines that a normal communication path from the server to the server machine cannot be established, and ends with a communication error.

FIG. 17 is an explanatory diagram of the operation of the above conventional example. The client process 4 of the client machine 2 of the host-C is connected to the LAN through the communication port 2S. The DBMS server process 3 of the host-S server machine 1 is connected to the LAN through the communication port 1S. 10 for each of communication ports 1S and 2S
19, 1020, 1021, ..., 2014, 201
It consists of ports such as 5, ...

In the UNIX-based communication line, a network address is defined, and this network address is, for example, "133, 139, 0.2", and the upper three digits are assigned to a company or a university. It is a code, and the next three digits represent the communication route. If it is "139", it is the route of LAN5, if it is "140", it is the LAN6.
The last two digits represent the code for each sales office or factory in the company. In this case, "0.1" represents the server machine 1 and "0.2" represents the client machine 2.

Next, the operation will be described. If you specify the network address "133, 139, 0.1" in the application program from the client machine,
Host-S from the communication port 2014 to the LAN 5 route
The communication port 1S is connected to 1019 (port 1), and the client process 4 and the DBMS server process 3 can execute processing according to a predetermined program.

If there is an abnormality in the LAN 5, the client process 4 detects this abnormality and sets the network address to "133, 140, 0.1", and from the communication port 2S 2015 through the LAN 6 to the server machine 1.
The communication port 1S is connected to 1020 (port-2) and the processing is continued.

The instruction of the communication path and the selection at the time of abnormality are described in an application program in the client process 4 and executed. That is, the client machine 2 specifies and executes the partner server machine (host-S), the communication port (port 1), and the processing process (program) by the application program of the client process 4, and if the path is abnormal, it is different. port
To switch the route.

[0014]

Since the conventional software configuration (FIG. 16) includes the route selection logic in the client process as described above, the application program needs to have an interface dedicated to the route selection logic. . That is, it is necessary to change the interface with the DBMS library, which is usually held by an application program that does not have a route selection logic using a single LAN.

The present invention has been made in order to solve the above problems, and the application program does not change the program on the normal single LAN at all, and the change of the communication form between the machines ( The objective is to build a server / client system that can handle changes in communication paths and communication protocols.

The following are prior art documents of this type. Japanese Unexamined Patent Publication (Kokai) No. 5-219076 discloses that a communication path is selected according to the situation thereof.
Japanese Patent No. 88054 describes means for performing communication between different protocols.

[0017]

[Means for Solving the Problems]

A server / client type system according to claim 1 of the present invention comprises a server machine having a database and a client machine for accessing the server machine to make a request for data in the database. In the server-client type system for communicating between the client machine and the client machine, the server machine is provided with a server process for processing data in the database, and the client machine is provided with a client process for making a data request to the database. A pseudo server process and a pseudo client process for establishing a communication path and performing communication according to the conditions of the communication path are provided in the server machine and the client machine, respectively.

According to a second aspect of the present invention, in the server-client type system according to the first aspect, the client process accesses a pseudo client process in its own client machine, and the server process is in its own server machine. While accessing the pseudo server process, the pseudo client process and the pseudo server process establish a communication path according to the conditions of the communication path, and request and process data through this communication path.

According to a third aspect of the present invention, in the server-client type system according to the first or second aspect, the pseudo client process and the pseudo server process select a desired communication protocol for different communication paths of the communication protocol. This is a process for establishing a communication path.

According to a fourth aspect of the present invention, in the server-client type system according to any one of the first to third aspects, when there is a data request from a client machine side to a database by a plurality of client processes, each A plurality of sets of pseudo client processes and pseudo server processes corresponding to client processes are generated, and communication paths are established by the pseudo client processes and pseudo server processes of each set.

According to a fifth aspect of the present invention, in the server-client type system according to any one of the first to third aspects, when there is a data request from a client side to a database by a plurality of client processes, a pseudo client process is performed. In addition, a plurality of sets of communication sockets corresponding to the above client processes are generated in the pseudo server process, and communication paths are established through the respective sets of communication sockets.

According to a sixth aspect of the present invention, in the server-client type system according to any one of the first to fifth aspects, the pseudo client process and the pseudo server process use a communicable path or a path with a small communication volume. This is a process for selecting and establishing a communication path.

According to a seventh aspect of the present invention, there is provided a server / client type system according to any one of the first to sixth aspects, which is a DBMS (database management system).
It has been applied to.

A server / client type system according to an eighth aspect of the present invention is applied to the X window system according to any one of the first to sixth aspects.

[0026]

In the server / client system according to claim 1 of the present invention, when a data request is made from a client process, the pseudo client process and the pseudo server process establish a communication path according to the conditions of the communication path, and the server process Executes the data processing corresponding to the data request.

In the server-client type system according to claim 2 of the present invention, the client process accesses the pseudo client process in its own client machine, and the server process accesses the pseudo server process in its own server machine. The pseudo client process and the pseudo server process establish a communication path according to the conditions of the communication path and request and process data through this communication path.

In the server-client type system according to claim 3 of the present invention, the pseudo client process and the pseudo server process establish a communication path by selecting a desired communication protocol for different communication paths of the communication protocol.

In the server-client type system according to claim 4 of the present invention, when there is a data request to the database from the client machine side by a plurality of client processes, a plurality of sets of pseudo client processes corresponding to each client process and A pseudo server process is generated, and a communication path is established by each set of the pseudo client process and the pseudo server process.

In the server / client type system according to claim 5 of the present invention, when there is a data request from the client side to the database by a plurality of client processes, a plurality of pseudo client processes and pseudo server processes are provided corresponding to each client process. A set of communication sockets is generated, and a communication path is established through each set of communication sockets.

In the server-client type system according to claim 6 of the present invention, the pseudo client process and the pseudo server process select a communicable path or a path with a small communication volume to establish a communication path.

A server / client type system according to claim 7 of the present invention is applied to a DBMS (database management system).

The server / client type system according to claim 8 of the present invention is applied to an X window system.

[0034]

EXAMPLES Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a server machine, 2 is a client machine, and 3 is a DBMS resident on the server machine 1.
Server processes 4 are client processes on the client machine 2. Reference numerals 5 and 6 are LANs, 7 and 8 are communication paths, and 9 is a database accessed by the DBMS server process 3. Reference numeral 10 is a pseudo server process, 11 is a pseudo client process, and communication between machines via the network is handled by the pseudo server process and the pseudo client process.

FIG. 2 is a software configuration diagram of the first embodiment. The same reference numerals as those in FIG. 1 represent the same functions. In the figure, 12 is a network that serves as a communication path between machines, and client process 4 is an application program 1.
3 and the DBMS library 14. Pseudo server process 10 and pseudo client process 1
15 in 1 is a network route selection logic. 16 is one of the communication ports of the client machine 2, and 17 and 18 are each one of the communication ports of the server machine 1.

Next, the operation will be described. The request from the application program 13 to the server machine 3 is sequentially followed as follows. The request from the client process 4 to the database 9 is transmitted to the inter-process communication port 16 and is received by the pseudo client process 11 which is waiting for the received data at the communication port 16. Next, the pseudo client process 11 uses the port 17 of the server machine 3
Data is transmitted to the port 17 and is received by the pseudo server process 10 that is waiting for the received data at the port 17. Finally, the pseudo server process 10 transmits data to another port 18 of the server machine 3, and the port 18 receives the data by the DBMS server process 3 which is waiting for the received data.

The route selection logic 15 in the pseudo server process 10 and the pseudo client process 11 in charge of communication between machines dynamically switches the routes 7 and 8 in FIG. 1 to realize data transmission / reception. An example of this route selection logic is shown in FIG. In addition to the function shown in FIG. 3, it is also possible to add a function for ensuring the reliability of communication, such as a data retransmission function. This change in logic does not affect the existing (standard for single LAN) client process 4 and the DBMS server process 3.

As described above, the application programs of the client process 4 and the DBMS server process 3 can use the standard program for the single LAN, and the execution of this application program allows the data of its own client machine 2 to be executed. The pseudo client process 11 takes charge of all the subsequent securement of a communication path, switching in the event of an abnormality, etc., only by sending to the pseudo client process 11, and the DBMS server process 3 of the server machine 1 is the pseudo server in its own machine. It is only necessary to receive and process the data from the process, and the pseudo server process 10 executes all the processes related to the communication.

Details of this operation will be described with reference to FIG. When the client process 4 specifies the “communication port 1 (2014) of the client machine 2” and transmits data, the pseudo client process 11 waiting for data reception on the port 1 (2014) receives the data from the client process 4 and both processes 4 Communication between 11 and 11 is established. After that, the pseudo client process 11 specifies "server machine 1, communication port (1030) of server machine 1" and transmits data. The pseudo server process 10 waiting for data reception at the same port (1030) receives the data from the pseudo client process 4 and then both processes 1
Communication between 1 and 10 is established.

The pseudo server process 10 transmits the received data to the DBMS server process 3 via the port-1 (1019) of the communication port 1S, and the DBMS server process 3 accesses the database 9 to perform a predetermined process. Also, the result or the like is transmitted to the client machine 2. If there is an abnormality in the LAN 5 line, the pseudo client process 11 sends L from another port (not shown).
AN6, select the port of the other party, pseudo server process 1
Establishes a path with 0. Pseudo server process 10 and DB
The connection between the MS server processes 3 is not changed even when an error occurs, and a signal is sent through the port 1 (1019) to execute a predetermined process.

In this manner, the pseudo server process / pseudo client process captures the communication data between the normal server process / client process of the server / client type system operating on the normal single LAN so as to intercept it, and Since all communication between them is controlled, it is not necessary to change the program of the server-client type system which normally operates in the single LAN. Therefore, the application program developer does not need to be aware of the communication form between machines at all, and since the process of processing data and the pseudo process are independent, the process development and the test can be performed completely independently. Further, the pseudo server process / pseudo client process can be applied not only to one type of application but also to an unspecified server / client type system using the same communication protocol.

Accordingly, the client process and the server process leave the pseudo-client process and the pseudo-server process to perform processing related to communication such as establishment of a communication path and processing at the time of path abnormality without changing the application program to be executed. be able to.

Example 2. In the above-described first embodiment, the LAN2 duplication server / client type DBMS is
Pseudo client process with redundant route selection function
By placing a pseudo server process on each machine,
The case of constructing a server / client type DBMS compatible with LAN duplication without changing the existing server / client type DBMS system has been described. As shown in FIG. 5, the pseudo client process / pseudo server process communicates with the network. A function corresponding to the type of protocol can be provided.

As shown in FIG. 5A, a server / client type DBMS using a communication protocol TCP-IP.
If there is a system, as shown in FIG. 5B, the system is not changed, and the pseudo client process and the pseudo server process are interposed in the inter-machine communication, so that the U
Server / client DB that supports various communication formats including WAN (Wide Aea Nerwork) such as DP, LLC, AppleTalk, ISDN using public telephone lines, etc.
The MS can be built.

Example 3. Moreover, in the above-mentioned Example 1, LA
Server / client type DBMS supporting N1 duplication, L
By allocating a pseudo client / server process having an AN duplex path selection function to each machine, a LAN / duplex compatible server / client type D can be used without changing the existing server / client type DBMS system.
The case of building a BMS has been described, but in FIG.
An example is shown in which a pseudo client process / pseudo server process is interposed in an X window system which is a server / client window system compatible with N1 duplication.

FIG. 6A shows an X window system using a communication protocol TCP-IP via a single LAN 5, which includes an X client process 31 and an X server process 3.
0 is transmitted and received using the communication protocol TCP-IP. This system is provided with a pseudo client process 11 and a pseudo server process 10 as shown in FIG. 6B, connected to the network 12, and the pseudo client process 11 and the pseudo server process 10 establish a route in the network 12. Select and establish.

By constructing the pseudo client process 11 and the pseudo server process 10 with the LAN duplication support function described in the first embodiment and the various communication protocol support functions described in the second embodiment, a network multiplexing support window system is constructed. it can.

FIG. 7 shows an example of the above.
The X server process 30 and its own server machine 1 have processes for performing different processes of the X client processes C1, C2, and C3, respectively, and the X server process 3 is also performed by these client processes C1, C2, and C3.
0 can be accessed to perform a predetermined process. The X client process C1 is provided with a process for counting and displaying the date and time, and the X client process C2 is provided with a process for actually measuring or predicting weather conditions (clear rain, atmospheric pressure, temperature, humidity, etc.) and displaying them.

The client machine 2 is provided with a client process C4, which is related to, for example, monitoring and controlling the electric power system, and can display these electric power systems and let the observer understand the situation.

FIG. 8 shows an example of the screen displayed on the CRT of FIG. 7. The date and time are displayed by the X client process C1 at the upper part of the screen and the weather condition is displayed by the X client process C2 at the lower part of the screen. To be done. A system diagram of the power system and its control status are displayed in the center of the screen.
Even in such a display system, the network 12
It is possible to select and secure the communication path in the pseudo client process and the pseudo server process. For example, this system can display the screen display of the developed software on a remote display server via a public network as a demonstration to a remote customer without changing the application software.

Example 4. In the first embodiment, there were two routes between the server and the client, but as shown in FIG.
There may be four routes. In the figure, 21 is a network management process, 22 is a network management table having information on the location (machine name, PORT number) of the pseudo server process 10, and 23 is a network status data table, which is data for managing the availability status of the network. is there.

The request from the client process 4 is received by the pseudo client process 11, and the pseudo client process 11 sends the request to the pseudo server process 10 on the server machine to the network 12.
The network management process 21 that manages the network status data table 23 is queried as to which LAN in which to transmit the data, and the data is transmitted via the optimum LAN.

Example 5. Although the number of client processes is one in the first embodiment, FIG. 10 shows an example of an implementation method when requests from a plurality of client machines are issued to the server machine. This is a pair of pseudo client processes per client process.
In this method, a set of pseudo server processes is forked to establish a connection with the server machine. This fork is a command on a UNIX machine, which branches like a fork, that is, the same program is copied from one parent program to create a child program. Is used to generate a pseudo process.

In the figure, 24 is a pseudo server process waiting for a request, and 25 is a pseudo client process waiting for a request. PC1, PC2, and PC3 are child pseudo client processes spawned from the parent pseudo client process 25. PS1, PS2, PS3, P
S4 is a child pseudo server process spawned from the parent pseudo server process 24.

The pseudo client process 25 waiting for a request, which has received the request from the client process C1, creates a child pseudo client process PC1, and this pseudo client process PC1 selects a route and sends it to the pseudo server process 24. . Upon receiving the request from the client, the request-waiting pseudo server process 24 creates a child process in the state where the connection with the client is established, and the parent process becomes the request-waiting pseudo server process 24 again.

In response to the requests from the client processes C2, C3, C4, the pseudo client process 11 of PC2, PC3, PC4 is generated, and in response to this, the pseudo server process 24 has PS2, PS3, PS3.
A pseudo server process of a child of PS4 is created and the DBMS server process 3 is accessed.

Example 6. This embodiment shows an example of an implementation method when requests from a plurality of client machines are issued to a server machine as in the case of the fifth embodiment. This is a method in which a pseudo client process and a pseudo server process generate a pair of communication sockets for each client process, thereby establishing a connection with the server machine. This socket is UNI
This is a command on the X machine that creates a communication socket for each different request in one process, and the present invention uses this command for a pseudo process.

In FIG. 11, 24 is a pseudo server process waiting for a request, and 25 is a pseudo client process waiting for a request. The pseudo client process 25 that receives the request from the client process C1 creates a socket, the pseudo server process 24 receives the request from the created socket via the LAN, creates one socket, and establishes a connection. Perform predetermined data processing. And C2. C3
If there is a request from, the socket corresponding to this request is generated and the communication path is established. Then, it again waits for a request from a new client on the request waiting socket.

In the fifth embodiment, a pair of pseudo server / pseudo client processes are created for a pair of client / server connections and the number of processes is increased. However, in the sixth embodiment, this process increase can be avoided. The amount of memory used can be reduced.

[0060]

As described above, according to the server / client type system of claim 1 of the present invention, a pseudo server process and a pseudo client for establishing a communication path according to a communication path separately from a process for processing data. Since the process is provided, the data processing process can be manufactured and used independently without being restricted by communication conditions such as a communication path and a communication form. Also, the pseudo server process and the pseudo client process can be produced and used independently of the data processing process.

According to the server-client type system of claim 2 of the present invention, the client process accesses the pseudo client of its own machine, and the server process processes the data only by accessing the pseudo server process of its own machine. Since this is executed, there is an effect that data processing can be performed without being aware of the communication path.

According to the server-client type system of claim 3 of the present invention, the pseudo client process and the pseudo server process select a desired communication protocol for communication paths having different communication protocols and establish the communication path. Since this is done, there is an effect that various communication protocols can be supported.

According to the server-client type system of claim 4 of the present invention, a plurality of sets of pseudo client processes and pseudo server processes corresponding to a plurality of client processes are generated, and the pseudo client processes and pseudo servers of each set are generated. Since each process establishes a communication path, there is an effect that data processing can be performed in response to requests from a plurality of clients.

According to the server-client type system of claim 5 of the present invention, a pseudo client process and a pseudo server process and a plurality of communication sockets are generated corresponding to a plurality of client processes, and the communication sockets of each set are generated. Since the respective communication paths are established, there is an effect that data processing can be performed according to requests from a plurality of clients.

According to the server-client type system of claim 6 of the present invention, the pseudo client process and the pseudo server process are processes for establishing a communication path by selecting a communicable path or a path having a small amount of communication. Therefore, there is an effect that reliable transmission can be performed.

According to the server / client type system of claim 7 of the present invention, since it is applied to a DBMS (database management system), a reliable DBM is provided.
There is an effect that S can be provided.

According to the server / client type system of claim 8 of the present invention, since it is applied to the X window system, there is an effect of providing a reliable X window system.

[Brief description of drawings]

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

FIG. 2 is a software configuration diagram of FIG.

FIG. 3 is a flowchart of a route selection algorithm for LAN duplication in FIG.

FIG. 4 is an operation explanatory diagram of the server / client type system of FIG. 1;

FIG. 5 is a configuration diagram of a server / client type system according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a server / client type system according to a third embodiment of the present invention.

FIG. 7 is an operation explanatory diagram of FIG. 6;

FIG. 8 is a diagram showing a screen of the CRT shown in FIG. 7.

FIG. 9 is a configuration diagram of a server / client type system according to a fourth embodiment of the present invention.

FIG. 10 is a configuration diagram of a server / client type system according to a fifth embodiment of the present invention.

FIG. 11 is a configuration diagram of a server / client type system according to a sixth embodiment of the present invention.

FIG. 12 is a configuration diagram of a server-client type system.

FIG. 13 is a server built on a conventional dual LAN
It is a block diagram of a client type system.

FIG. 14 is a configuration diagram of a conventional server machine.

FIG. 15 is a configuration diagram of a conventional client machine.

FIG. 16 is a software configuration diagram of a conventional server / client type system.

FIG. 17 is an operation explanatory diagram of a conventional server / client type system.

[Explanation of symbols]

1 server machine, 1a, 1b interface card, 1S communication port, 2,2-1,2-2 client machine, 2a, 2b interface card, 2S communication port, 3 DBMS server process,
4 client processes, 5, 6 LAN, 7, 8
Route, 9 database, 10 pseudo server process, 11 pseudo client process, 12 network, 13 application program, 14 DB
MS library, 15 network route selection logic, 16, 17, 18 communication port, 21 network management process, 22 network management table, 2
3 network status data table, 24 pseudo server process, 25 pseudo client process, 30
X server process, 31 X client process.

Claims (8)

[Claims] 1. A server machine having a database,
And a client machine for accessing this server machine to make a request for the data in the above database,
In the server-client type system for performing communication between the server machine and the client machine, the server machine includes a server process for processing data in the database, and the client machine for performing a data request to the database. And a pseudo server process and a pseudo client process for establishing a communication path according to the conditions of the communication path and performing communication are respectively provided on the server machine and the client machine, and when the client process makes a data request, the pseudo process is executed. The client process and the pseudo server process establish a communication path according to the conditions of the communication path, and the server process executes data processing corresponding to the data request. Server-client system according to claim. 2. The client process according to claim 1, wherein the client process accesses a pseudo client process in its own client machine, and the server process accesses a pseudo server process in its own server machine. The server / client type system, wherein the client process and the pseudo server process establish a communication path according to the conditions of the communication path and request and process data through this communication path. 3. The pseudo client process and the pseudo server process according to claim 1, wherein the pseudo client process and the pseudo server process are processes for establishing a communication path by selecting a desired communication protocol for communication paths having different communication protocols. Server / client system. 4. The method according to any one of claims 1 to 3,
When there are data requests from the client machine side to the database by multiple client processes, multiple sets of pseudo client processes and pseudo server processes corresponding to each client process are created,
A server / client type system characterized in that a communication path is established by each of the pseudo client process and the pseudo server process. 5. The method according to any one of claims 1 to 3,
When there are data requests to the database from the client side by multiple client processes, multiple sets of communication sockets corresponding to each of the above client processes are created in the pseudo client process and pseudo server process, and communication is performed through the communication sockets of each set. A server / client type system characterized by establishing a route. 6. The method according to any one of claims 1 to 5,
The server / client system is characterized in that the pseudo client process and the pseudo server process are processes for selecting a communicable path or a path having a small amount of communication to establish a communication path. 7. The method according to any one of claims 1 to 6,
A server / client type system characterized by being applied to a DBMS (database management system). 8. The method according to any one of claims 1 to 6,
A server / client type system characterized by being applied to an X window system.