JPS63305431A - Terminal connection transfer system between plural host computers - Google Patents

Abstract

PURPOSE:To effectively utilize a storage area by providing a terminal connecting status management table for managing the connecting states of terminals on storage device shared for all host computers. CONSTITUTION:The connecting states of the terminals 61-6n connected to the whole system are managed by the common terminal connecting states managing table 31 formed in the storage device 3 to be accessed in common from respective host computers 1, 2. Respective host computers 1, 2 updates the corresponding part in the table 31 at the time of connecting the terminals 61-6n with application programs 14, 15, 24, 25 and at the time of disconnecting the connection. Since the connecting states of all the terminals 61-6n are managed by the table 31, when either of the host computer 1 or 2 has a fault, a normal host computer can acquires connecting information relating to a terminal to be transferred by checking the table 31. Consequently, the using efficiency of the storage area can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a terminal connection takeover method for multiple host computing institutions that reconnects a terminal connected to a failed host computer to another normal host computer. Regarding.

[Conventional technology]

A multiple-host computer system in which multiple host computers are provided in the computer system, and each host computer connects and communicates with a terminal device or other computer system via a line switching device or a communication control device, or both. Conventionally, when a failure occurs in one of the host computers, a terminal connected to the failed host computer is automatically reconnected to another normal host computer.

Conventionally, the following methods are known as such terminal connection takeover methods between multiple host computers.

■ Each host computer has a management table that manages the status of terminals connected to the entire multi-host computer system, and all operating host computers Update the management table. Therefore, each time there is a change in the connection status with the terminal on each host computer,
Notify other host computers of changes in terminal status.

If a failure occurs in any running host computer,
Other normal host computers determine the terminal connected to the faulty host computer from their own management table, and
Reconnect the application program on the host computer and the terminal as necessary.

■ A control computer is installed to manage the status of terminals connected to the entire multi-host computer system, and the terminal connection status is managed all at once. Each host computer notifies the control computer of this information when the connection status of a terminal is changed. When a failure occurs in any of the operating host computers, the control computer notifies each of the operating host computers of the terminals connected to the failed host computer, and the host computers that receive this notification do the following: Reconnect the application program of the local host computer and the terminal as necessary.

[Problem that the invention seeks to solve]

The conventional terminal connection takeover methods between multiple host computers described above each have the following problems.

In method (2), all host computers have a management table that shows the connection status of terminals connected to the host computers of the entire system, so from the perspective of each host computer, information that is normally unnecessary must be stored. This inevitably results in poor usage efficiency of the storage area.

In addition, every time a terminal is connected to a host computer or a connected terminal is disconnected, the management tables of all host computers must be updated, resulting in poor processing efficiency. Control becomes complicated because the management table on the host computer must be updated at the same time.

In the method (■), the connection information of the terminals connected to the entire system is collectively managed by the control computer, so unlike the method (■), there is no possibility that the usage efficiency of the storage area will be poor or the processing efficiency will be reduced. Although this is rare, it requires a dedicated computer, which increases the cost of the entire system. Furthermore, since the terminal status managed by the control computer and each host computer must be updated at the same time, control becomes somewhat complicated.

The present invention aims to solve these conventional drawbacks.

[Means for solving problems]

In order to solve the above-mentioned conventional problems, the present invention provides a terminal between multiple host computers that reconnects a terminal that was connected to a failed host computer among multiple host computers to another normal host computer. In the connection takeover method, a terminal connection status management table that stores the connection status of each terminal is provided on a storage device that can be commonly accessed by each host computer, and each host computer establishes a connection between the terminal and the application program. The terminal connection status management table is updated when the connection is disconnected, and when a failure occurs in one of the host computers, the terminal connected to the failed host computer is reset to another normal terminal. When reconnecting to a new host computer, the takeover destination host computer acquires connection information regarding the terminal to be taken over by referring to the terminal connection status management table.

[Effect]

The connection status of terminals connected to the entire system is managed in a common terminal connection status management table provided on a storage device that can be commonly accessed from each host computer. That is, each host computer updates the corresponding portion of the terminal connection state management table when it establishes a connection between a terminal and an application program and when it disconnects the connection. In this way, the connection status of all terminals is managed by a common terminal connection status management table, so if a failure occurs in any host computer, the other normal host computers can manage the terminal connection status. By checking the table, connection information regarding the terminal to be taken over can be obtained.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a multiple host computer system to which the present invention is applied, in which two host computers 1.2
An example of a system including

In the figure, host computer 1.2 has channel s+,
5t to the storage device 3 such as a disk device,
Memory bag r! Terminal connection status management table 31 stored on 13
The configuration is such that both host computers 1.2 coexist. One way to share a large-scale storage device such as a disk device between multiple host computers is to store the database used by an application program on a shared storage device, and share the database while controlling it exclusively at the block level. Although the form is known, the memory bag Wt3 in this example
The terminal connection state management table 31 is also shared by each host calculation a1.2 using these exclusive control techniques.

That is, updates that occur simultaneously from each host computer 1.2,
Exclusive control is performed on reference requests.

Further, the host computer 1.2 is connected to the communication control device 4 through channels 5s and 5*, and the communication control vtW4 is connected to the communication line 7. It is connected to terminals 61 to 6n through terminals 61 to 6n. Each of the terminals 61 to 6n can be connected to any of the host computers fil, 2 by the communication control device 4. Note that a line switching device may be provided instead of or in addition to the communication control device 4.

Each host computer 1.2 has terminal connection means 11゜21.
, a terminal disconnection means 12.22, a terminal reconnection means 13.23, and a plurality of application programs 14.15.24.25
(The names of application programs 14 and 24 are A, and the names of application programs 15 and 25 are B).

FIG. 2 is a diagram showing an example of the contents of the terminal connection state management table 31. As shown in the figure, the terminal connection state management table 31 has a structure in which it has a plurality of entries with entry numbers E1 to En, and each entry corresponds to one terminal. Each entry has a terminal name field 201. Terminal status field 202. It consists of a connected host number field 203 and a connected application program name field 204.

゛ Fig. 3 is a flowchart of an example of processing performed when the terminal connection means 11.21 receives a terminal connection request from an application program, and Fig. 4 shows an example of processing performed when the terminal disconnection means 12.22 receives a terminal disconnection request from an application program. FIG. 5 is a flowchart of an example of the processing performed by the terminal reconnection means 13.23. The operation of this embodiment will be explained below with reference to each figure.

In the system shown in FIG. 1, the host computer 1-2, the storage device 31, and the communication system 24 are operating normally, the application program 14-15 is running as the active system on the host computer 1, and the application program 14-15 on the host computer 2 is operating normally. Application program in 24.25
It is assumed that each of the application programs 14 and 15 is operating as a standby application program.

In this state, from the current application program, for example, the application program 14, to the terminal, for example, the terminal 6, which becomes the terminal connection means 11,
1 is issued, the terminal connection means 1
1 searches for the entry of the requested terminal 61 from the terminal connection status management table 31 in step 301, as shown in FIG.
), determine the terminal status of the corresponding entry (step 30
2). If this determination is that the connection is in progress, the application program 14 is notified that the connection has failed (step 308).
If reconnecting, terminal 6. Send a connection request to the terminal (step 303) and wait for a response from the terminal (step 30).
4) Determine the response (step 305), and if it is an accepted response, set the terminal status field 202 of the corresponding entry in the terminal connection status management table 31 to "connected",
At the same time, the connected host number field 203 is updated to the host number "1" of the own host computer l, the connected application program name field 204 is updated to the name rAJ of the application program 14 (step 306), and the terminal 6. The application program 14 is notified of the completion of the connection (step 307).

Furthermore, if there is a negative response in step 305, the application program 14 is notified of the failure in connection with the terminal 6I (
Step 308).

This process is executed every time a terminal connection request is made from an application program. A connection request from a terminal to an application program is processed in the same way by the terminal connection means 11, and the terminal connection status management table 31
Each field of the corresponding terminal entry is updated to "Connected" or the like.

On the other hand, when the application program 14 issues a request to disconnect from the terminal 61 due to the end of the business, etc., this request is sent to the terminal disconnection means 12.

As shown in FIG. 4, the terminal disconnection means 12 searches the terminal connection status management table 31 for the entry of the requested terminal 61 (step 401), and updates the terminal status field 202 to "disconnected" (step 402). . After that, the terminal 61
Send a disconnection request to the terminal 61 (Step 403), wait for a response from the terminal 61 (Step 404), and determine the response.
(Step 405), and if it is an acceptance response, notify the application program 14 of the completion of disconnection from the terminal 61 (Step 406), and if it is a negative response, step 4
03 and resends the disconnection request. Repeat until there is an acceptance response.

The above terminal disconnection process is executed every time a terminal disconnection request is issued from an application program. Even when accepting a disconnection request from a terminal,
Even in the event of a disconnection event due to line failure, etc., the terminal disconnection method 1
2, the terminal connection state of the corresponding terminal entry in the terminal connection state management table 31 is updated to "disconnected".

As described above, the connection/disconnection status with each terminal is always reflected in the terminal connection status management table 31.

Now, when a failure occurs in the host computer 1, the host computer 2 detects that the failure has occurred in the host computer 1 due to a timeout for exchanging operation monitoring data (health check), reception of failure notification data from the host computer lit, etc. is detected, and the terminal reconnection means 23 in the host computer 2 is activated.

When the terminal reconnection means 23 is activated, it acquires the entry of the terminal connected to the faulty host computer 1 from the terminal connection state management table 31 as shown in FIG. 5 (step 501).
, 502, 503), compare the application program name of the corresponding entry with the name of the application program that was waiting in the host computer llz (step 504), and if they match, set the terminal status field 202 of the corresponding entry to "Disconnect". In step 505), the terminal connection means 21 is requested to connect the corresponding terminal and its application program in its own host computer 2 (step 506). This process connects the terminal connected to the faulty host computer 1 to the designated standby application program.

The terminal reconnection means 23 connects all the terminals to be taken over, which are identified based on the contents of the terminal connection state management table 31, to the waiting application program as necessary.

In the above embodiment, there are only two host computers, but there are three
Similar control can be used to take over the terminal connection state for a multiple host computer system in which more than one host computer exists.

〔Effect of the invention〕

As explained above, the present invention is a system in which the terminal connection state management table for managing the connection state of terminals is stored on a storage device shared by all host computers. It is no longer necessary for each host computer to have duplicate information that is not used, and storage space can be used effectively.In addition, each host computer updates the above terminal connection status management table when connecting or disconnecting a terminal. Processing efficiency is improved because only one system is required.Furthermore, since the physical configuration is such that only the storage device is shared, the cost of the entire system is lower than that of conventional method (2), and control is simpler.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of a multi-host computer system to which the present invention is applied, FIG. 2 is a diagram showing an example of the contents of the terminal connection status management table 31, and FIG. 3 is a diagram showing the terminal connection means 11.21 is an application program. 4 is a flowchart of an example of processing performed when the terminal disconnection means 12.22 receives a terminal connection request from an application program, and FIG. 5 is a flowchart of an example of processing performed when the terminal disconnection means 12. 2 is a flowchart of an example of the processing of the connection means 13.23; In the figure, 1.2... host computer, 3... storage device, 4...
・Communication control device, 5. ~5ka...channel, 61~6
n...Terminal, 7°~7n...Communication line, 11.21
...Terminal connection means, 12.22...Terminal disconnection means,
13.23...Terminal reconnection means, 14°15, 24.
25...Application program, 31...Terminal connection status management table, 201...Terminal name field, 202...Terminal status field, 203...Connection host number field, 204...Connection application program name field.

Claims (1)

[Claims] In a terminal connection takeover method between multiple host computers in which a terminal connected to a failed host computer among multiple host computers is reconnected to another normal host computer, A terminal connection status management table that stores the connection status of each terminal is provided on a commonly accessible storage device, and each host computer has a terminal connection status management table that stores the connection status of each terminal. The terminal connection state management table is configured to update, and when a failure occurs in one of the host computers, the terminal connected to the failed host computer is reconnected to another normal host computer, A terminal connection takeover method for multiple host computing institutions, characterized in that the takeover destination host computer obtains connection information regarding the terminal to be taken over by referring to the terminal connection state management table.