JP3215963B2 - Network system and communication method in the system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer system in which a plurality of computers are connected to a large-scale network (WAN: Wide Area Network), a local area network (LAN: Local Area Network), etc., and communicate with each other. In particular, the present invention relates to a network system and a communication method in the system for reducing a CPU load of a computer performing communication and a load of the communication device.

[0002]

2. Description of the Related Art Two-way communication between computers includes, for example, TCP / IP (Transmission Control Protocol / Information).
(Point to Point) transmission method such as ternet Protocol)
UDP / IP (User DatagramProtocol / Internet Proto
col) There is a transmission method using a protocol.

The TCP / IP protocol is generally a transmission control protocol having high reliability and providing one-to-one communication, and has a transmission error check function, a retransmission function when an error occurs, and the like. In this communication method, a connection method that always connects the computer and the functions inside the computer on a one-to-one basis is used.
On the other hand, the UDP / IP protocol has an advantage that it can be transmitted to a plurality of parties at the same time, but generally has low reliability such as no transmission error check function and no error retransmission function.

As described above, the TCP / IP protocol is more reliable than the UDP / IP protocol,
In the prior art, when priority is given to reliability, a communication system using the TCP / IP protocol is generally used. In the conventional distributed processing system using the TCP / IP protocol, each of the lower-level computer groups individually communicates with the upper-level computer.

[0005]

However, if each of the lower computer groups individually communicates with the upper computer as in the above prior art, the communication data amount is large or the number of lower computers increases. In this case, the upper computer C
There is a problem that the PU load and the communication load of the network connecting the upper computer and the lower computer group are significantly increased.

As one means for solving this problem, it is possible to introduce a higher-performance computer into the system to reduce the communication load, but a new cost problem arises.

Further, Japanese Patent Application Laid-Open No. Hei 3-19450 discloses that
It has been proposed to reduce the communication load on the lower computer side and the communication load on the network due to unilateral communication on the upper computer side by providing a communication protocol between the upper computer and the lower computer. CPU
It is not enough to reduce the load.

An object of the present invention is to provide a lower-level computer group with a parent-child relationship when communicating between a higher-level computer and a lower-level computer group in a distributed processing system including a higher-level computer and a lower-level computer group. It is an object of the present invention to provide a network system and a communication method in the system, which can significantly reduce the CPU load and the communication load of the network.

[0009]

In order to achieve the above object, the present invention comprises an upper computer and a plurality of lower computers connected to the upper computer. In a network system that communicates with the lower computer , the lower computer first notified or connected to the upper computer
The computer is recognized as a parent computer, and the recognized parent computer is
Between the plurality of lower computers and the upper computer
A communication means is provided.

[0010]

[0011] The present invention also provides a network system having the above-described configuration, which communicates with the lower-level computer and communicates with the lower-level computer.
The parent computer that communicates with the upper computer is the lower computer.
Selecting means for selecting from the deviations;
The plurality of lower computers and the higher
Means for communicating with a computer .

Further, a large-scale network system can be constructed by providing two or more network systems having the above configuration and connecting them to each other by connecting means.

Furthermore, the communication method of the present invention, communication with host computer, when communicating between a plurality of lower computer connected to the host computer, one of the lower computer and the host computer determined as the parent computer to the plurality of lower computer is that it has to communicate with the host computer via the master computer.

[0014]

In a distributed processing system comprising a host computer and a group of lower computers, when communication is performed between the host computer and the group of lower computers, an increase in the load on the host computer and the network causes a direct increase in the load on each of the lower computers. It is proportional to the number of communication executions. Therefore, if configured as described above,
All subordinate computer including identified parent computer, so communicates with the host computer via the master computer. That is, the upper computer only needs to communicate with one lower computer among the plurality of lower computers.
The load and the communication load on the network are reduced.

As described above, one of the lower-level computers is designated as the parent computer.
Determined as a computer, if the lower computer fails, since there is a possibility that communication between the host computer and lower computer becomes impossible, either the parent computer subordinate computer
So that you can choose from them. If you do this,
When a lower computer that has been communicating with a higher computer breaks down, communication can be continued by switching the parent computer to another lower computer.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a network system according to the present invention. This network system is WAN
(Wide Area Network) 1, an upper computer 2, and a lower computer group 3 having n lower computers.
The WAN 1 and the upper computer 2 are connected by a communication line 4, and the upper computer 2 and the lower computer group 3 are connected by a communication line 5.

One of the lower computer groups 3 is set as the parent computer 6 and the other lower computer is set as the child computer 7. When data is transmitted to and received from the lower computer group 3, the upper computer 2 Is performed via the parent computer 6. For example, from the upper computer 2 to the lower computer group 3
, The upper-level computer 2 transmits data only to the parent computer 6. Parent computer 6 that received the data
Holds the data and transmits the data to the child computer 7. Conversely, when transmitting data from the lower computer group 3 to the upper computer 2, if the lower computer to be transmitted is the parent computer 6, the data is directly transmitted to the upper computer 2, and the higher computer 2 receives this. The child computer 7 is the child computer to send.
If so, the child computer 7 sends the data to the parent computer 6,
After holding the data once, the parent computer 7 transmits the data to the host computer 2 and the host computer 2 receives the data.

When configured as described above, the host computer 2
Does not need to individually communicate with each computer of the lower-level computer group 3 and only needs to communicate with the parent computer 6, so that an increase in load due to communication processing can be significantly reduced.

FIG. 2 shows a schematic flow of the data transmission process between the upper computer and the lower computer group. The upper computer determines whether the transmission / reception partner is a lower computer (step 10).
0), if it is not a lower computer, it performs transmission / reception processing with the WAN (step 101 ), and performs processing in its own computer based on the transmission / reception data (step 102). Step 100
When it is determined that the transmission / reception partner is a lower computer, the upper computer performs transmission / reception processing with the parent computer of the lower computer group (step 103), and performs processing in its own computer based on the transmission / reception data (step 103). 104). After performing the processing in steps 102 and 104, it is determined whether or not the processing has been completed (step 105).

Next, the operation of the upper computer and the lower computer group when the upper computer transmits data to the lower computer group will be described with reference to FIG. In the figure, the upper computer checks the parent computer of the lower computer group (step 11).
0), all data is transmitted to the confirmed parent computer at a time (step 111). The parent computer of the lower computer group receives all the data transmitted from the upper computer (step 112), and selects a child computer to hold the data and transmit the data from the lower computer group (step 113). ), And transmits data to the selected child computer (step 114). The child computers in the lower-level computer group receive the data sent from the parent computer (step 115), perform the processing in their own computer (step 116), and then return a response signal indicating that the data has been received (step 116). Step 117). Then, the parent computer of the lower-level computer group receives the response signal from the child computer (step 118), transmits the signal to the higher-level computer (step 119), and the higher-level computer receives the response (step 110). .

FIG. 4 schematically shows how data is transmitted and received between the upper computer and the lower computer. As shown in the figure, a data area (for P1) for the parent computer 6 is provided in the upper computer 2 and the parent computer 6 of the lower computer group 3.
And a child computer 7 data area (for P2 to Pn). The data of the parent computer 6 and the data of all the child computers 7 can be transmitted and received between the host computer 2 and the parent computer 6. Parent computer 6 and child computer 7
The parent computer 6 sends and receives data to and from each child computer 7 individually. FIG. 5 shows the details of the data held by the host computer and the host computer group.

Next, how to determine the parent computer from the lower-level computer group will be described. FIG. 6 is a flowchart showing the parent-child determination process of the upper computer and the lower computer group and the start-up process of the lower computer group. During the start-up process, the lower-level computer group inquires of the higher-level computer about the parent computer of the lower-level computer group (Step 130). In response to that inquiry,
The upper computer checks which computer is the parent computer and passes the result to the lower computer (step 131). The lower computer that has received the above result determines whether or not the parent computer exists (step 132), and if so, connects the communication with the parent computer and starts the business (step 1).
33). If the parent computer does not exist, the parent computer is notified to the host computer that the parent computer is the own computer (step 13).
4).

The host computer receives this notification and checks whether there is another first-come-first-served notification to determine whether or not the notified computer can be recognized as the parent computer (step 135). If there is no other first-arrival notification, the lower-level computer that sent the notification is recognized as the parent computer, communication is connected, and at the same time, the parent computer starts work. If the upper computer has a first-come-first-served notification, the computer that sent the notification is notified of the parent computer, and the lower computer starts work with the parent computer. The computer whose identification number registered in the parent computer of the communication management table (which will be described later) matches the identification number of its own device operates as the parent computer.

FIG. 7 shows the configuration of the computer system shown in FIG. The upper computer 2 is provided with a communication management table 10 in which the identification number 11 of the currently connected parent computer and the identification number 12 of the communicable lower computer that can be the parent computer are stored. Is stored. The communication management table 13 is also provided in the parent computer 6 and the child computer 7 of the lower computer group. The communication management table 13 includes the identification number 14 of the currently connected upper computer and the currently connected parent computer. The identification number 15 of the computer and the identification number 16 of a communicable lower-level computer that can be the parent computer are stored. Then, the communication partner of the lower computer is determined by rewriting the identification number of the parent computer in these communication management tables as needed.

Next, a method of switching the parent computer when the parent computer of the lower computer group stops for some reason will be described. As shown in FIG. 8A, when the parent computer 6 stops, the communication between the host computer 2 and the child computer 7 is disconnected. Each computer (both the upper computer 2 and the child computer 7) that has detected an abnormality by disconnecting the communication clears the parent computer column of the communication management table shown in FIG. Each child computer 7 attempts to connect to the host computer 2, and the child computer 7 connected first is recognized by the host computer 2 as a parent computer as shown in FIG. Subsequently, the other child computer 7 to be connected is notified of the first connected computer as a new parent computer from the host computer 2, reconnects with the new parent computer, and resumes business. However, when the parent computer 6 stops, the host computer 2
If communication has been performed between the server and the lower-level computer group, the communication cannot be guaranteed, so that transmission and reception must be performed again.

(Second Embodiment) In the first embodiment described above, since there is one parent computer, when the number of lower computers increases, the communication load of the parent computer and the load of the communication line increase. . Therefore, in the present embodiment, the parent computer is defined so as to be able to communicate with the n lower computers as long as the original business of the upper computer is not alienated, and is connected to the upper computer 2 as shown in FIG. The parent computers 20 and 21 are provided, and the parent computer 20 has (n−1) child computers 22.
However, (n-1) child computers 23 are connected to the parent computer 21 respectively.

The communication method is the same as that of the first embodiment, except that the communication load is reduced on each communication line by dividing the communication line as shown in FIG. By reducing the number of child computers depending on the computer, it is possible to suppress an increase in the load due to communication of the parent computer.

As shown in FIG. 10, parent computers 25 and 26 are connected to the host computer 2 via a communication line 24, and n parent computers 22 are connected to the parent computer 25 via a communication line 27. When the parent computer 26 is connected to the n child computers 23 via the communication line 28, transmission between the host computer 2 and the parent computers 25 and 26,
5 and the child computer 22 and between the parent computer 26 and the child computer 23
The transmission between them is separated, and the load on the communication line can be balanced.

In the case of the configuration of the computer system shown in FIGS. 9 and 10, this is dealt with by setting the number frame of the identification number of the parent computer of the host computer to n. In the lower computer group, the identification number of the upper computer, the identification number of the currently connected parent computer, and the identification number of the communicable lower computer group that can be the parent computer are provided as a communication management table. An inquiry is made to the host computer in the start-up process of FIG. 6 based on the identification number of the host computer in the communication management table. When the connection with the parent computer is made based on the result of the inquiry, the identification number of the parent computer is not included in the result, and the parent computer is notified to the host computer that the parent computer is the host computer, and the host computer is the parent computer to the host computer. When it is recognized, the column of the parent computer in the communication management table is rewritten.

(Third Embodiment) FIG. 11 shows an example in which a group of lower computers is further hierarchized. That is, a lower computer group including a parent computer 31 and (n-1) child computers 32 is connected to the upper computer 2 via the communication line 30. The parent computer 31 has a communication line 3
3 and lower-level grandchild computers 37 and 38 to the grandchild computer 32 via a communication line 36. Here, grandchild computer 3
4 and the great-grandchild computer 37 are parent computers, and the grandchild computer 35 and the great-grandchild computer 38 are child computers. Parents, children, grandchildren,
Hierarchy such as great-grandchildren may be multiplexed.

FIG. 12 is a processing flow when the lower-level computer group is hierarchized. For example, considering the parent computer 31 as a reference, it is determined whether or not the target is the next lower computer group, that is, the grandchild computer group (step 140). If it is not the next lower computer group, it is in the own computer group, that is, in the parent computer 31 and child computer 32 Is performed (step 141), and it is determined whether the processing is completed (step 142). When it is determined in step 140 that the target is the next lower computer group,
The data is transmitted to the next lower-order computer group, that is, the grandchild computer group (step 143), and it is determined whether or not the transmission processing has been completed (step 144).

FIG. 13 schematically shows how each computer transmits and receives data in the case of hierarchization. The transmission and reception of data between the upper computer and the lower layer computer group of the first hierarchy are the same as those shown in FIG. The transmission and reception of data between the lower-layer computer group of the first hierarchy and the lower-layer computer group of the second hierarchy are basically the same as those in FIG. 4 except that the data amount is reduced. The same applies to the case between other layers.

In the case of this embodiment, the communication management table is provided for each of the host computer, parent, child, grandchild, and great-grandchild. The configuration is basically the same as that of the first embodiment. good. Further, the communication method may be basically the same as in the first embodiment.

According to this embodiment, by hierarchizing the parent, child, grandchild, and great-grandchild, it is possible to increase the number of lower-level computers installed while suppressing an increase in the load due to the communication of one parent computer. is there.

(Fourth Embodiment) FIG.
In this example, two WANs 1 in which a parent computer 41 and a lower-level computer group 43 composed of child computers 42 are connected are coupled by a coupling device 44. Also in this case, the child computers 42 in the lower computer group 43
To communicate with When communication is performed between different WANs 1, one host computer 41 transmits and receives data to and from the other host computer 41 via the coupling device 44. In this embodiment, an example in which two WANs 1 are connected is shown. However, three or more WANs 1 may be provided, and each may be connected by the connecting device 44.

[0036]

As described in detail above, according to the present invention,
Since the lower-level computer group has a parent-child relationship, and the upper-level computer always communicates only with the parent computer of the lower-level computer group, the CPU load of the upper-level computer and the communication load of the network can be greatly reduced.

As a result, when the communication performance of the host computer is not sufficient or when it is not desired to increase the load of communication,
A large-scale computer system can be constructed without introducing a high-performance and high-priced computer.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a network system according to a first embodiment of the present invention.

FIG. 2 is a flowchart of a data transmission process between an upper computer and a lower computer group.

FIG. 3 is a diagram illustrating operations of a higher-order computer and a group of lower-order computers when transmitting data.

FIG. 4 is a diagram schematically showing a state of data transmission and reception between an upper computer and a lower computer.

FIG. 5 is a diagram showing data contents held by a host computer and a host computer group;

FIG. 6 is a flowchart of a parent-child determination process and a startup process of a lower-level computer group.

FIG. 7 is a configuration diagram of a communication management table set for an upper computer and a lower computer group;

FIG. 8 is a diagram showing a state in which a parent computer is switched.

FIG. 9 is a configuration diagram of a network system according to a second embodiment of the present invention.

FIG. 10 is a diagram showing a modification of the network system of FIG. 9;

FIG. 11 is a configuration diagram of a network system according to a third embodiment of the present invention.

FIG. 12 is a flowchart showing a processing procedure when a lower-level computer group is hierarchized.

FIG. 13 is a diagram schematically showing a state of data transmission and reception between computers when hierarchization is performed.

FIG. 14 is a configuration diagram of a network system according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 WAN 2,40 host computer 3,43 host computer group 4,5,24,27,28,30,33,36 communication line 6,20,21,25,26,31,41 parent computer 7,22,23 , 32,42 child computer 34,35 grandchild computer 37,38 great child computer 44 coupling device

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-195239 (JP, A) Patent 3062904 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06F 13/00 G06F 13/10-13/14

Claims (7)

(57) [Claims] 1. A network system comprising an upper computer and a plurality of lower computers connected to the upper computer, wherein communication is performed between the upper computer and the lower computer. A network system, comprising: means for recognizing a connected lower computer as a parent computer and communicating with the plurality of lower computers and the higher computer via the recognized parent computer. 2. The network system according to claim 1 , wherein there are a plurality of computers recognized as the parent computer, and the plurality of lower-level computers are connected to each of the computers. system. 3. A network system comprising an upper computer and a plurality of lower computers connected to the upper computer, wherein the network system communicates between the upper computer and the lower computer. Selecting means for selecting a parent computer to communicate with a higher-level computer from any of the lower-level computers; and means for performing communication between the plurality of lower-level computers and the higher-level computer via the parent computer selected by the selecting means. , A network system comprising: 4. The network system according to claim 3 , wherein said selecting means has a function of switching the parent computer from the selected current lower-level computer to another lower-level computer. 5. The network system according to claim 3 , wherein the lower-level computer selected as the higher-level computer and the parent computer has the selected lower-level computer and another lower-level computer as management files. Characteristic network system. 6. The method of claim 1 to 5 of the network system according to a large-scale network system, characterized in that two or more joined the network system connecting means. 7. When communicating between an upper computer and a plurality of lower computers connected to the upper computer, one of the lower computers is determined as a parent computer for communicating with the upper computer. A communication method for a network system, wherein the plurality of lower computers communicate with the upper computer via the parent computer.