JPH0916495A - Communication control method - Google Patents

Abstract

PURPOSE: To dynamically set an optional communication protocol corresponding to the operating conditions of a system or the like and to efficiently transfer data by performing data transfer control for shifting from a present control state to the other control state based on a control operation definition table. CONSTITUTION: After a session establishing processing between both computers is completed, a specified control operation to be executed when a specified control event is generated under a certain control state and the other control state to shift to are dynamically set in the state transition definition table 10 of the respective computers for all the combinations of the shiftable control states and the generatable control events. Then, the respective computers obtains the control operation to be executed and the control state to shift to from the state transition definition table 10 corresponding to the present control state and the control event during generation. Then, based on the control operation definition table defined in common beforehand, the present control state is shifted to the other control state and data transfer is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control method in an online system in which a plurality of computer systems are connected via a communication line, and in particular, it dynamically sets an optimum communication protocol according to the system status. And a communication control method for transferring data.

[0002]

2. Description of the Related Art Generally, when data is transmitted / received between a plurality of programs operating in different computer systems via a communication line, various attributes (data transfer amount, data type) relating to data to be transferred. And a feature etc.), a specific communication protocol that seems to be optimal is determined in advance, and a processing procedure for performing communication control according to the communication protocol is incorporated in the programs on the transmission side and the reception side in advance. , The communication is always performed according to the same communication protocol during a series of communication processes such as mutual connection through a communication line → transmission / reception of transfer data → disconnection of the line connection.

However, when the attributes of the data to be transferred are not always constant and change frequently, it is difficult to define one optimal communication protocol, or one communication protocol is specified. By doing so, a considerable waste may occur in resources required for communication control, communication time, and the like. Therefore, conventionally, assuming multiple types of communication protocols in advance, prepare the necessary communication lines for each communication protocol, and then transfer the data while switching the communication lines and communication protocols according to the attributes of the data to be transferred. I was dealing with the communication control method of doing. In this case, since one communication line can only send and receive data according to one communication protocol, in addition to the number of communication lines according to the number of attributes of the data to be transferred, communication equipment and communication unique to each communication protocol It is necessary to provide management resources. Further, since data transfer in which all communication lines are used at the same time cannot occur, communication management resources are inevitably wasted.

In recent years, as a further improvement of the above conventional technique, a plurality of sets of virtual addresses are set at both ends of a communication line, and one communication line is virtually multiplexed so that one address is provided between the same addresses at both ends. A communication control method is known in which the number of physical communication lines to be actually prepared is reduced by performing communication control using a communication protocol. The point that a communication management resource is required is the same as the conventional one.

Then, recently, Japanese Patent Laid-Open No. 61-133
According to Japanese Patent Laid-Open No. 454 or Japanese Patent Laid-Open No. 3-271954, a plurality of interfaces are provided in advance on each of the computer systems at both ends connected via a communication line, and then the systems connected via one communication line are connected. A communication control method has been proposed in which, after dynamically selecting a communication protocol to be applied at the time of data transfer, data transfer based on the communication protocol is performed.

[0006]

However, no matter which of the above-mentioned conventional techniques is adopted, a specific method for realizing a communication protocol for data transfer with a partner system connected via a communication line is required. It is necessary to decide in advance about all the processing procedures. For example, if a line fault sense code is received during the reception of certain data, whether to return a negative response to the other system that is transmitting or whether to continuously wait for reception. If both systems do not match in advance, the data transfer itself will not be established. Therefore, in the above-mentioned conventional technique, a specific processing procedure corresponding to all kinds of communication protocols applicable to data transfer is prepared for both systems which intend to communicate via a communication line prior to the start of communication. However, there is a problem that a large number of resources in a computer system are occupied by a group of programs that execute such a processing procedure. Further, even if one computer system tries to communicate with a specific communication protocol, the data transfer itself cannot be established unless the processing procedure for realizing the communication protocol is prepared in the other system. .

On the other hand, prior to the start of the intended data transfer, a communication control program for realizing communication control according to a specific communication protocol is dynamically transferred to the partner system, and the communication control program is transferred. A communication control method that enables data transfer according to the communication protocol by allowing the other system to use the Since it is necessary to understand it, there is a problem that it is not very practical in a network in which computer systems composed of various kinds of hardware are connected in a mixed state.

Therefore, it is an object of the present invention to solve the above problems and to determine in advance by both systems a communication protocol applied to data transfer between computer systems connected via a communication line. Another object of the present invention is to provide a communication control method capable of dynamically setting an arbitrary communication protocol according to the operation status of the system and performing efficient data transfer.

[0009]

In order to achieve the above object, the communication control method of the present invention controls data transfer between a plurality of computers connected to each other via a communication line in accordance with a predetermined communication protocol. In the communication control method for performing, after the completion of the session establishment processing between both the computers, a specific control operation to be executed when a specific control event occurs under a certain control state and a transition after the control operation After dynamically setting other control states to be set in the state transition definition table under the control of each of the computers for every combination of control states that can transition and control events that can occur, , The control operation that should be executed in response to the current control state and the control event that is occurring, and other control status that should transition after the control operation From the state transition definition table, a specific processing procedure for realizing each control operation is executed based on a control operation definition table that is commonly defined in advance, The data transfer control for transitioning to another control state is performed.

[0010]

The operation based on the above configuration will be described.

A communication control method of the present invention is a communication control method for performing data transfer control between a plurality of computers connected to each other via a communication line in accordance with a predetermined communication protocol. After the completion of the session establishment process, a specific control operation to be executed when a specific control event occurs under a certain control state and other control states to be transitioned after the control operation,
For each combination of control states that can transition and control events that can occur, after dynamically setting in the state transition definition table under the control of each said computer, each said computer The control operation to be executed corresponding to the control event and the other control state to be transitioned after the control operation are obtained from the state transition definition table, and a specific processing procedure for realizing each control operation is described in advance. A communication protocol applied to data transfer by executing the control operation based on the commonly defined control operation definition table and performing data transfer control for transitioning from the current control state to the other control state. There is no need to decide in advance and prepare a program group etc. corresponding to the communication protocol in each computer. Since it is possible to dynamically set the communication protocol depending on the operational status of the system,
Efficient data transfer can be performed by making maximum use of the resources of each computer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the communication control method of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing an example of the configuration of a state transition definition table in the communication control method of the present invention. In the state transition definition table 10 of FIG. 1, the row indicated by reference numeral 11 is a “state column” for defining various “states” (ST1 to ST3) that can transit, and the column indicated by reference numeral 12 indicates occurrence. This is an "event column" in which various possible "events" (EV1 to EV3) are defined. The columns other than the "state column" 11 and the "event column" 12 are various "actions" to be executed (ACT1
~ ACT7) and "state" (ST1 to ST3) to be transitioned after the execution of the "operation" is defined as "transition column". For example, if the "event" EV1 (reference numeral 16) occurs while the system is transitioning to the "state" ST3 (reference numeral 15), the system executes the "action" ACT3 (reference numeral 17) and then the "state" ST2. Transition to (reference numeral 18). In the above, "state", "event", and "action" are
“Control state”, “control event”, and “control action” in the claims
Is equivalent to

FIG. 2 is a diagram showing a basic configuration example of a communication processing system for realizing the communication control method of the present invention. In the figure, a program 22 executed on the computer 21
Has a function of performing data transfer control via the communication line 24 using the input / output device 23. Similarly, the program 26 executed on the computer 25 is the input / output device 27.
Has a function of controlling data transfer via the communication line 24. Hereinafter, details of the communication control method performed by the programs 22 and 26 will be described.

FIG. 3 is an explanatory diagram relating to the processing for setting the state transition definition table shown in FIG. 1, and FIG. 3A is a communication control processing 31 relating to data transfer control in the program 22 or 26 in FIG. , The state transition definition table setting process 32 and the data transfer process 33 are shown in FIG.
(B) and (c) are state transition definition table setting processing 3
Specific control instruction data for No. 2 are shown. In FIG. 3A, the communication control processing 31 is an OSI (Open System) for establishing and releasing a session with a communication partner, transmitting and receiving various control data relating to communication control, and the like.
s Interconnection) to control the basic communication processing defined in the layers below the session layer in response to a request from a higher-level program. State transition definition table setting process 32
Automatically determines the communication protocol by setting the state transition definition table 10 under the control based on the control instruction data transmitted from the computer of the communication partner after the session establishment process is completed. The data transfer process 33 controls a substantive data transfer process defined in a layer higher than the session layer of OSI based on a control operation definition table described later and the state transition definition table described above.

That is, when the specific contents of each "transition column" are transmitted from the computer of the communication partner via the communication line, the communication control processing 31 determines from the contents of the "transition column" in FIG. ), The control instruction data including the array number 301, the subroutine number 302, and the transition destination state number 303 are obtained, and the state transition definition table setting process 32
Pass to The state transition definition table setting process 32 identifies the "transition column" by the array element number 301 of the passed control instruction data, and then the subroutine number 302 as "operation" and the transition destination as "state". The state number 303 is stored in each "transition column". Then, the format of FIG.
When the state transition definition table setting end code 39 as shown in (c) is transmitted, the state transition definition table setting process 32 for setting the communication protocol for data transfer.
Is completed and control is transferred to the data transfer processing 33 for performing substantive data transfer.

FIG. 4 is an explanatory diagram of a data transfer process based on the control operation definition table and the state transition definition table. In FIG. 4A, the communication control process 31 controls the basic communication process in response to the request from the upper program as described above. The event determination processing 331 and the state transition definition table reference processing 332 are each part of the data transfer processing 33 shown in FIG. 3, and the processing contents will be described later. FIG. 4B shows the subroutine number 302 and the transition destination state number 303 set in the “transition column” in the state transition definition table 10 based on the control instruction data described above. FIG. 4C shows a specific configuration example of the control operation definition table described above. The address table 34 specified by the subroutine number 302 set in the “transition column” in the state transition definition table 10 includes The start addresses of the subroutines 341 to 345 prepared in advance for realizing a specific “operation” are stored.

Here, since the "state" specified by the state number can be an initial state, a transmission data generation waiting state, a transmission completion waiting state, a reception waiting state, etc., it is common to all communicating computers. The state number is defined in advance. Further, as a concrete subroutine for realizing the "operation", a subroutine for queuing the received data in the reception queue, a subroutine for discarding the received data, a subroutine for transmitting the transmission data in the transmission queue, and a transmission queue for the transmission data There is a subroutine to delete from, a subroutine to queue a negative response to the transmission queue, a subroutine to queue an acknowledgment to the transmission queue, a subroutine to queue an error message to the transmission queue, a subroutine to wait without doing anything, etc. Subroutines that implement the same processing procedure are set in advance in all computers that perform communication using common subroutine numbers corresponding to these functions.

The event determination processing 33 determines the "event" generated by the operation of the communication control processing 31 according to a predetermined condition, and then the "event" is set in the state transition definition table 10. Of the event number table 331.
Set to a. Here, as the “event”, reception completion, transmission completion, positive response reception, negative response reception,
Possible line failure, queue failure, etc. As for the line number for identifying each "event", the same line number is used for all computers that communicate.

The state transition definition table reference process 332, which is activated after the event determination process 33 is performed, is the current state number set in the state number table 332a and the occurrence set in the above-mentioned event number table 331a. The array in the state transition definition table 10 is specified based on the generated event number, and its contents, that is, the subroutine number 30
2 and the transition destination state number 303 are referred to, the subroutine corresponding to the subroutine number 302 is called by referring to the control operation definition table 34, and the obtained value of the transition destination state number 303 is set in the state number table 332a. .

[0021]

As described in detail above, according to the communication control method of the present invention, data transfer control is performed between a plurality of computers connected to each other via a communication line in accordance with a predetermined communication protocol. In the communication control method, after the completion of the session establishment processing between both the computers, a specific control operation to be executed when a specific control event occurs under a certain control state, and transition after the control operation For each combination of control states that can be transited and control events that can occur, the control state of is dynamically set in the state transition definition table under the control of each computer, and then each computer The control operation to be executed corresponding to the control state and the control event being generated and other control states to be transitioned after the control operation are described above. From the state transition definition table, a specific processing procedure for realizing each control operation is executed based on a control operation definition table that is commonly defined in advance. By performing the data transfer control to transit to the control state, it is not necessary to decide the communication protocol to be applied to the data transfer in advance and prepare the program group corresponding to the communication protocol in each computer. Since it is possible to dynamically set the communication protocol according to the operating status of the system, etc., it is possible to make the most of the resources of each computer and achieve the effect of efficient data transfer. To be

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a state transition definition table in a communication control method of the present invention.

FIG. 2 is a diagram showing a basic configuration example of a communication processing system that realizes the communication control method of the present invention.

FIG. 3 is an explanatory diagram related to a process of setting a state transition definition table shown in FIG.

FIG. 4 is an explanatory diagram related to data transfer processing based on a control operation definition table and a state transition definition table.

[Explanation of symbols]

 31 communication control processing 32 state transition definition table setting processing 33 data transfer processing 331 event determination processing 331a event number table 332 state transition definition table reference processing 332a state number table

Claims (1)

[Claims] 1. A communication control method for performing data transfer control between a plurality of computers connected to each other via a communication line in accordance with a predetermined communication protocol, after completion of a session establishment process between both the computers. , A specific control action to be executed when a specific control event occurs under a certain control state, and another control state to be transitioned after the control action, of a control state that can transit and a control event that can occur. For every combination, after dynamically setting in the state transition definition table under the control of each said computer, each said computer should perform the control corresponding to the current control state and the control event that is occurring. The operation and other control states to be transitioned after the control operation are obtained from the state transition definition table, and each control operation is realized. The specific processing procedure is to execute the control operation based on a control operation definition table defined in advance in common, and perform data transfer control for transitioning from the current control state to the other control state. Communication control method.