JPH07245640A - Method for re-raising communication path and communication equipment therefor - Google Patents

Abstract

PURPOSE:To surely release a communication path with an active system on the occurrence of a fault. CONSTITUTION:An active system 3 sends an association establish reply and reply system identification information (R information) being own system identification information to a starting system 1. The above starting system 1 adds the R information to a succeeding establish request and sends the resulting information to a reply system 2, and the reply system compares the R information with its own system identification information at that time and sends NG information to the starting system 1 when the both are dissident. Thus, even when an establish request (3) is issued in almost the same timing as the switching from the active system 3 to a standby system 4, the reply of the standby system 4 with respect to the request indicates NG information the association in a communication path being an object of the active system is not newly established after the association established by a forced release request (4) is released.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is based on the concept of a communication path between an invoking system and a working system of a responding system (for example, a hot standby system). When the standby system operates instead of this due to the management system going down, the communication path is once released, and then a new communication path is reestablished between the initiating system and the standby system. The present invention relates to a communication method and a communication device.

Note that, as shown in FIG. 6, the "association" used in this specification is a logical communication path established between the system A and the system B, and also referred to as "communication path". Is a concept that bundles associations between the same systems.

The system on the startup side is made aware of the communication partner system of each association by managing a plurality of associations in units of this communication path.

Further, in such communication by managing the communication path, the communication path (old communication path) up to that time is temporarily released after the active system of the responding system is down, and the starting system and the standby system are connected. Although a new communication path is established between them, it is required that the release of the old communication path be surely performed at this time, and the present invention responds to such a request. .

[0005]

2. Description of the Related Art FIG. 7 is an explanatory diagram showing a normal process of normally switching from an active system b to a standby system c in a hot standby system 12, the contents of which are as follows. Note that the hot standby system is a system in which the standby system continuously executes the processing there when the active system goes down.

(31) The initiating system 11 sends an association establishment request to the hot standby system 12 before executing a predetermined work by data transfer, and when the active system b receiving this request can establish an association. The association establishment response of "OK" is transmitted. Then, by repeating the above process, the communication paths consisting of the number required for the work, for example, 100 associations, are established, and these association numbers are entered in the communication path management table. (32) If the active system b goes down due to a failure in the middle of data processing using these initial associations, the work contents of the active system b at that time are handed over to the standby system c. (33) The standby system c releases the communication path up to that time, which may have been involved in the occurrence of the failure, and the starting system 11
An association forced release request is sent to the invoking system 11 in order to newly establish a communication path with the. And
Upon receiving this association forced release request, the invocation side system 11 releases the communication path up to that point, that is, the communication path of each association number entered in the communication path management table. (34) Subsequently, the activation-side system a sends an association establishment request to the hot standby system 12 and reestablishes the communication path by the same processing as (31).

FIG. 8 is an explanatory view showing the erroneous connection process during switching of the hot standby system 12 from the active system b to the standby system c, which is different from the case of FIG. 7 in the following points. There is.

That is, as shown in (43), at the same timing as the switching from the active system b to the standby system c,
A new request for establishing an association is sent from the invoking system a to the hot standby system 12, and the standby system c receives the request. ・ As shown in (45), the system waits for this extended association establishing request. The difference is that system c has sent an "OK" association establishment response.

Therefore, after all of the established associations, for example, 100 established up to that time, are released based on the association release request, for example, one association is established as a component of the communication path up to that time. The initiating system 11, which has received the association release request, attempts to establish a new communication path with the hot standby system 12 as indicated by (46), but it fails.

[0010]

As described above, in the communication path establishing method between the conventional activation side system and the response side system having the active system and the standby system, the response side system changes from the operation system to the standby system. If there is an association that the initiating system is trying to establish while switching to, the communication path that should have been released may remain unreleased, in which case the initiating system will respond. There is a problem that a new communication path cannot be established with the host system.

Therefore, in the present invention, at least the response establishment system identification information which is the ID of the response side system is added to the association establishment response from the response side system to the activation side system, and the subsequent association establishment from the activation side system is added. This ID is also added to the request and sent to the responding system, and the responding system receiving this compares the received ID with its own ID to wait for an association establishment request in the communication path of the active system. The purpose is to prevent the system from issuing the association establishment response of "0K" and ensure the release of the communication path.

[0012]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 1 is an initiating side system 2 having an association establishment request control unit 5 and a communication path management table 6 and the like, 2 is a responding system consisting of an active system 3 and a standby system 4, 3 is an association establishment response control unit 7 and a communication system. The active system 4 having the path management table 6 and the like has the association establishment response control unit 7 and the standby system 5 having the communication path management table 6 and the like have the transmission of the association establishment request added with the I / R information and the I / R information The association establishment request control unit 6 that controls the processing such as the reception of the added association establishment response and the release of the communication path displays the self-side system identification information, the transmitted partner-side system identification information and the established association number. The communication path management table 7 to be filled in is the transmission of the association establishment response with I / R information added. And the association establishment response control unit for controlling the processing such as reception of the association establishment request to which the communication and I / R information is added and transmission of the association forced release request.

The I information is the system identification information on the starting side, which corresponds to the system identification information on the self side when seen from the association establishment request control section 5, and is transmitted when seen from the association establishment response control section 7. The other party's system identification information that has been received corresponds.

The R information is the system identification information on the response side, which is opposite to the identification information on the I side and corresponds to the identification information on the other side transmitted from the viewpoint of the association establishment request control section 5. When viewed from the association establishment response control unit 7, the own system identification information corresponds.

Here, each of the association establishment response control units 7 of the active system 3 and the standby system 4 responds to the association establishment request from the invoking system 1 if the R information is an initial value or if the R information is If the R system information is not the initial value and does not match the own system identification information, the association establishment “NG” response is sent. Send to 1 respectively.

Further, the manner of establishing and releasing the association between the activation side system 1 and the response side system 2 is as follows. The association establishment request control unit 5 of the activation side system 1 sends an association establishment request to which the I / R information is added to the response side system 2, and the working system 3 which receives the request.
The association establishment response control unit 7 repeats sending the association establishment response according to the above rule as many times as necessary, and executes predetermined data processing between both systems unless there is a response of "NG" association establishment in the middle. The required number of initial associations are established and each association number is entered in the communication path management table. If the active system 3 goes down during subsequent system operation, the standby system 4 takes over. At the same time as the switching to the standby system 4, a request for establishing an extended association is issued to the activation side system 1.
From the responding system 2 and the standby system 4
May receive this establishment request at a timing when it can be processed. In this case, the sent R information (the own system identification information of the active system 3) and the own system identification information of the standby system 4 are different. On the other hand, the standby system 4 first sends an association forced release request to the activation side system 1, and the activation side system 1 receiving this request releases all the associations already established. At this time, the association number in the communication path management table 6 of the activation system 1 is deleted. Since the invoking system 1 receives "NG" as the establishment response from the standby system 4 in response to the above-mentioned request for establishing the extended association, the extended association is not established as in the conventional case, and the cause of the down of the active system 3 is caused. Any communication paths that may have been involved in the are reliably released once. After that, the activation-side system 1 reestablishes the communication path for the standby system 4 by sending an association establishment request to the response-side system 2 as in the step.

[0017]

As described above, according to the present invention, at least the so-called ID of the sender system is added to at least the association establishment response, and this ID is also added to the subsequent association establishment request from the invoking system 1. Each of the responding systems 3 and 4 receiving the response returns to the responding system 2, which is a hand, and compares the received ID with its own ID to determine whether or not this association establishment request is intended for itself. I checked it.

An initial value is used as the ID to be added to the first association establishment request, and the ID of the responding system must be added to the establishment response to this request, but in the subsequent association establishment response. To what ratio is this ID added?
For example, whether or not to add the ID of the responding system to all association establishment responses after the second one is arbitrary.

Further, this ID, that is, the system identification information on its own side, may be any information uniquely corresponding to each system, and various kinds of information such as system time information, system serial number and network address are used.

Further, although the communication path management table of the initiating side system and the response side system identification information entered therein are necessary for the present invention, whether or not to provide the communication path management table in the response side system, Is I in the communication path management table
Whether or not information is entered is optional. However, if I information is also used, the responding system can recognize the initiating system of the communication partner.

It should be noted that the sharing of the system on the starting side and the system of the responding side, and the sharing of the system on the active side and the system on the standby side are both relative. Will be the current system.

Further, when a request for establishing an extended association is sent from the invoking system 1 to the responding system 2 at the same time as the switching to the standby system 4,
The fact that the standby system 4 receives this establishment request at a timing when it can be processed means that when the active system 3 is down, the standby system 4 continuously executes the processing there. It is more likely to occur than a system, and is more effective when the present invention is applied to a hot standby system.

[0023]

Embodiments of the present invention will be described with reference to FIGS. FIG. 2 is an explanatory diagram showing an example of a protocol sequence. Here, OSI-TP (Open System Interconne
PD used in communication (Transaction-Transaction Processing)
Time stamp information (time information), which is information outside the protocol, is added to U (Protocol Data Unit) based on the protocol of OSI. Note that the PDU can be used in other protocols as well.

Here, the starting side time stamp information and the response side time stamp information in the establishment request and the establishment response of each association are as follows: 'when an initial association (first association) establishment request is made. Start-up time (a) -Response side time stamp information = initial value (0) 'When establishing response of initial association (first association) -Start-up time stamp information = Start-side time (a) -Response side time stamp Information = time at response side (b) 'when requesting establishment of extended association-Time stamp information at activation side = time at activation side (a) -Time stamp information at response side = time at response side (b)' when response to establishment of extended association・ Timer information of the startup side = time of the startup side (a) ・ Time stamp of the response side Information = time at response side (b) 'when requesting establishment of extended association-Time stamp information at activation side = time at activation side (a) -Time stamp information at response side = time at response side (b)' When establishment response for extension association • Time stamp information on startup side = time on startup side (a) • Time stamp information on response side = time on response side (c), and in case of ′, time on response side received (b) and time on own response side (c) ) Is a non-coincidence, and it is an association establishment rejection response.

FIG. 3 is an explanatory diagram showing a processing procedure when transmitting an association establishment request, and the contents thereof are as follows. (1) Judge whether the time stamp information of the local system and the remote system is held in the management table for each communication path. If "YES", proceed to the next step and
If “O”, proceed to step (3). Here, "NO"
Is when sending a request to establish an initial association. (2) The time stamp information of the local system of the management table is set as the time stamp information of the starting side, and the time stamp information of the partner system of the management table is set as the time stamp information of the response side, and the association establishment request is transmitted. (3) Enter the time stamp information of the local system in the establishment table for each communication path and proceed to the next step. (4) The time stamp information of the own system is set in the time stamp information of the starting side, and the initial value "0" is set in the time stamp information of the responding side, and the association establishment request is transmitted.

FIG. 4 is an explanatory diagram showing a processing procedure when an association establishment request is received, and the contents thereof are as follows. (11) It is determined whether the time stamp information on the response side is “0”. If “YES”, the process proceeds to step (14) and “N
If “O”, proceed to the next step. In addition, here, "YE
“S” is when the first association establishment request is accepted. (12) Determine whether the received time stamp information on the response side matches the time stamp information on the local system,
If "YES", proceed to step (16), and if "NO", proceed to next step. (13) The time stamp information of the local system is set in the time stamp information of the response side and the association establishment refusal response is transmitted to the invoking system. (14) Make a note of the time stamp information (startup time stamp information) of the other system notified by the association establishment request in the management table for each communication path. (15) Make a note of the time stamp information of the local system in the management table. (16) The time stamp information of the local system is set in the time stamp information of the response side, and the association establishment response of "OK" is transmitted to the activation system.

FIG. 5 is an explanatory diagram showing a processing procedure when an association establishment response is received, and the contents thereof are as follows. (21) Is the association establishment response rejected?
If it is the former case, the receiving process is terminated in the former case, and the process proceeds to the next step in the latter case. (22) It is judged whether or not the time stamp information (response side time stamp information) of the other system is held in the management table for each communication path. If "YES", this receiving process is terminated and "NO" In case of, proceed to the next step. (23) Make a note of the time stamp information of the other system (response time stamp information) in the management table.

[0028]

As described above, the present invention adds the response side system identification information, which is the ID of the response side system, to the association establishment response from the response side system (active system and standby system) to the activation side system. , This ID is also added to the subsequent association establishment request from the invoking system and sent to the responding system,
The responding system receiving this compares the received ID with its own ID, and the standby system issues an association establishment response of "0K" to the association establishment request in the communication path of the active system. This can be prevented and the release of the communication path can be ensured.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory diagram showing an example of a protocol sequence of the present invention.

FIG. 3 is an explanatory diagram showing a processing procedure for transmitting an association establishment request according to the present invention.

FIG. 4 is an explanatory diagram showing a processing procedure when receiving an association establishment request according to the present invention.

FIG. 5 is an explanatory diagram showing a processing procedure when receiving an association establishment request according to the present invention.

FIG. 6 is an explanatory diagram showing a general concept of a communication path.

FIG. 7 is an explanatory diagram showing a general hot standby system switching process.

FIG. 8 is an explanatory diagram showing general misconnection processing during hot standby system switching.

[Explanation of symbols]

 In FIG. 1, 1 ... Initiating side system 2 ... Responding side system 3 ... Active system 4 ... Standby system 5 ... Association establishment request control unit 6 ... Communication path management table 7 ...・ Association establishment response control unit

Claims (5)

[Claims] 1. An entire association established between a starting system and a working system of a responding system is managed by a concept such as a communication path between these two systems, and when the working system goes down, the stand-by system operates. When re-establishing a new communication path between the initiating system and the standby system after releasing the communication path when operating on behalf of, a method of re-establishing the communication path of the initiating system, The response side system identification information sent from the response side system together with the association establishment response is added to the subsequent association establishment request and is sent to the response side system, and the communication path between the activation side system and the operation system. When the reply to the request to establish the association is from the standby system. Is re-established method of communication paths initiator system characterized in that it does not establish a new association in accordance with the contents of the association confirmation rejection of that time. 2. The entire association established between the invoking system and the active system of the responding system is managed by a concept such as a communication path between these two systems, and when the active system goes down, the standby system takes over. When re-establishing a new communication path between the initiating system and the standby system after releasing the communication path when operating on behalf of the above, in the method of re-establishing the communication path of the responding system, Along with the association establishment response to the association establishment request from the initiating side system, the own side system identification information is sent to the initiating side system as response side system identification information, and then the initiating side system is added with this response side system identification information. The corresponding response received from the association establishment request sent from The side system identification information and the self side system identification information at that time are compared, and the content of the association establishment response is set according to the result, for the association establishment request in the communication path between the activation side system and the operation system. A method of reestablishing a communication path of a responding system, characterized in that when an answer is from the standby system, the content is rejected to establish an association. 3. The entire association established between the invoking system and the active system of the responding system is managed by a concept such as a communication path between these two systems, and when the active system goes down, the standby system takes over. In the method of reestablishing a communication path, the communication system reestablishes a new communication path between the initiating system and the standby system after releasing the communication path when operating in place of the responding system. Sends the self-sided system identification information as the response side system identification information to the activation side system together with the association establishment response to the association establishment request from the activation side system, and the activation side system which receives the response side system identification information is , Responsive system identification for subsequent association establishment request The response side system having added the information to the response side system, and receiving the association establishment request, the response side system compares the response side system identification information with the self side system identification information at that time, and establishes the association according to the result. When the content of the response is set, and the response to the association establishment request in the communication path between the initiating system and the operation system is from the standby system, the content becomes an association establishment rejection and a new A method for reestablishing a communication path, characterized in that an association is not established. 4. The entire association established between the invoking system and the active system of the responding system is managed by the concept of a communication path between these two systems, and when the active system goes down, this causes the standby system to operate. In the communication device of the activation side system, which is used when re-establishing a new communication path between the activation side system and the standby system after releasing the communication path once when operating on behalf of An association that controls each processing of transmitting an association establishment request with system identification information to the response side system, receiving an association establishment response with response side system identification information from the response side system, and releasing a communication path. The establishment request control unit, and the response side system identification information as the response side system identification information. Communication device of the initiator system, characterized in that a communication path management table that fill mating system identification information sent from the beam. 5. The entire association established between the invoking system and the active system of the responding system is managed by the concept of a communication path between these two systems, and when the active system goes down, the standby system takes over. In the communication device of the response side system, which is used when re-establishing a new communication path between the initiating side system and the standby system after releasing the communication path once when operating on behalf of Transmission of an association establishment response added with system identification information to the invoking system, reception of an association establishment response with the response side system identification information from the initiating system, and an association forced release request to the invoking system Controls each process of sending the, and receives the association establishment response. In the case of reason, the association establishment response control unit is configured to compare the response side system identification information added thereto and the self side system identification information at that time and set the content of the association establishment response based on the result. A communication device of a response-side system, comprising: