JPH0981408A - Computer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect an impossible communication between an on-line host and a display server by investigating the logical connection state between a host to the display server. SOLUTION: In a computer system in which plural host computers 2#1 and 2#2 are connected and an output control is performed for a display server 3 by an on-line client, diagnostic means 8#1 and 8#2 deciding the possible- impossible communication between the host computer having an on-line client and the display server 3 by exchanging a message via the display server 3 and an on-line changing means promoting either one of off-line clients which are the same as the on-line clients and are in standby to the on-line client when it is decided that communication is suspended between the host computer having the on-line client and the display server 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer system,
More specifically, it relates to a computer system characterized by a man-machine interface in a plurality of computers connected to a network.

[0002]

2. Description of the Related Art Conventionally, in a process monitoring device, a computer system has been used for its monitoring and control work. In particular, with the recent trend toward lower prices and higher performance of small computers such as workstations, computer systems in which a plurality of these workstations are connected as host computers have been used as process monitoring devices. There is.

A man-machine interface (MMI) in such a computer system is as shown in FIG.
In many cases, the display server is made redundant to improve reliability, and a separate display server is provided.

FIG. 3 is a block diagram showing an example of a conventional computer system. In the figure, the computer system includes a host 2 # 1 and a host 2 # 2 on the data transmission path 1 (hereinafter, referred to as host 2 when represented as a host).
And the display server 3 is connected.

Here, for example, a workstation is used as the host 2, that is, a host computer, and a workstation, a terminal such as an X-terminal, or a terminal is used as the display server 3.

The display server 3 includes a display function unit 4
And the display function unit 4 is a client process 5 # 1 or 5 # provided in the host 2 # 1 or 2 # 2.
The display is performed by input from 2 (hereinafter, referred to as client process 5 when represented as a client process).

Here, the client process handles the input / output of the screen of the display server 3, and outputs the information obtained from a certain process to the display server 3 as a necessary screen display.

Therefore, one host 2 has a plurality of client processes 3 according to the type of screen display (only one is shown in the figure), and each host 2 has a computer system The same client process is provided for redundancy. The client processes 5 # 1 and 5 # 2 are the same client process.

Further, in FIG. 3, two hosts 2 are provided.
However, this is merely an example, and a larger number of hosts 2 may be connected. Such redundancy is indispensable in a process monitoring device that requires extremely high reliability.

In this computer system, first, in order to make the display output from the display server 3,
The client process 5 of any one of the hosts 2 becomes online, and the display corresponding to the client process 5 is controlled only by the online client process 5.

Here, for the sake of explanation, it is assumed that the client process 5 # 1 is online and the client process 5 # 2 is offline. The display request function unit 6 # 1 of the client process 5 # 1 receives the input from the display server 3 and also according to a preset program, the display server 3
The necessary information is output to the display function unit 4 of. Display function unit 4
Performs the necessary display based on the information.

On the other hand, in such a computer system, a diagnostic function between the hosts 2 is provided in order to make the redundancy effective. As shown in FIG. 3, diagnostic function units 7 # 1 and 7 # 2 (hereinafter, referred to as diagnostic function unit 7 when represented as a diagnostic function unit) are provided in each host.

The diagnostic function unit 7 outputs a message to another host 2 and determines whether or not the other host 2 is operating normally depending on whether or not a reply is returned. For example, in the above case, the diagnostic function unit 7 # 2 of the host 2 # 2, which is an offline client, sends a message to the diagnostic function unit 7 # 1 of the host 2 # 1, and the diagnostic function unit 7 # 1
1 returns a reply.

The diagnostic function unit 7 # 2 of the host 2 # 2 determines that the host 2 # 1 is operating normally if a message is returned, and if the response is not received within a certain time, the host 2 # 1 It is determined that some failure has occurred in # 1 and the host has been stopped, and the host 2 # 2 is promoted to online.

In this case, the diagnostic host 7 # 2 has its own host 2
The client process 5 # 2 is notified that # 2 has been promoted to online. In this way, the display operation of the display server 3 by the client process 5 is continued.

In the above case, the host 2 is the host 2 #.
Although only two cases of 1 and 2 # 2 have been described, when the number of hosts 2 is further increased, a priority order for online promotion is set for each host 2, and one of the diagnostic function units 7 If the host finds that the online host has stopped, the host 2 is promoted online according to this priority.

[0017]

Originally, various cases are conceivable for the failure occurrence in the online host.
For example: 1) When the online host cannot communicate with all other devices (including other hosts and display servers). 2) When the online host can communicate with other hosts but cannot communicate with the display server. 3) The online host can communicate with other hosts and the display server, but its client process is abnormal.

In the conventional computer system described above,
In the case of 1) above, the abnormality can be detected by the diagnostic function. However, since the conventional diagnostic function cannot check the logical connection state between the host and the display server or between the host and the client process, it can be detected even if a failure occurs in the cases of 2) and 3) above. There was a problem that I could not do it.

The present invention has been made in consideration of such a situation, and its first purpose is to check the logical connection state between the host and the display server to check the communication failure between the online host and the display server. It is to provide a computer system which improves the reliability by surely detecting it.

A second object is to provide a computer system which improves the reliability by checking the logical connection state between the client process and the display server and surely detecting the communication failure between the client process and the display server. To provide.

[0021]

In order to solve the above problems, the invention according to claim 1 connects a plurality of host computers and at least one display server via a network, and outputs to the display server. Among the client processes for controlling the above, the same client process is provided in at least two or more host computers of each host computer, and one of the same client processes becomes an online client to control the output to the display server. Then, in the computer system in which the other same client process becomes an offline client and does not execute at least the output control operation to the display server, the host computer having the online client and the offline client Means for exchanging messages with a host computer having an online client via a display server to determine whether communication between the host computer having an online client and the display server is possible, and an online client by the diagnostic means. A computer system including an online changing unit that promotes one of the waiting offline clients to the online client when it is determined that the host computer having the above-mentioned and the display server are not connected to each other.

Next, the invention according to claim 2 is a client process for connecting a plurality of host computers and at least one display server via a network and controlling output to the display server.
When the same client process is provided in at least two or more host computers of each host computer and one of the same client processes is an online client and controls output to the display server, another same client process Is an off-line client and does not execute at least the output control operation to the display server. In the computer system, the same client process is provided.
Diagnostic means for determining whether communication between the online client and the display server is possible by exchanging messages between the online client and the offline client, and the online client and the display server by the diagnostic means. Is a computer system provided with an online changing means for promoting any one of the waiting offline clients to the online client when it is determined that there is no communication between them.

Therefore, first, in the computer system according to the first aspect of the invention, output control such as screen control, image output, and data display is performed by the online client with respect to the display server.

Next, the diagnostic means exchanges messages between the host computer having the online client and the host computer having the offline client via the display server, and based on the result of the message exchange, the host having the online client. Whether communication between the computer and the display server is possible or not is determined.

When the diagnostic means determines that the host computer having the online client and the display server are out of communication with each other, the online changing means promotes any of the waiting offline clients to the online client. It

As a result, the logical connection state between the host and the display server is checked, and when the logical connection is not established, another host and the display server are connected.

Therefore, the output control for the display server by the new online client is continued. Next, in the computer system according to the second aspect of the present invention, the online client performs output control such as screen control, image output, and data display on the display server.

Next, the diagnostic means provided in each same client process exchanges messages between the online client and the offline client via the display server, and based on the result of the message exchange, the online client and the display are exchanged. Whether communication with the server is possible or not is determined.

When the diagnostic means determines that the online client and the display server are out of communication with each other, the online changing means promotes any of the waiting offline clients to the online client.

As a result, the logical connection state between the client process and the display server is checked, and when the logical connection is not made, another same client process and the display server are connected. Therefore, the output control for the display server by the new online client is continued.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. (First Embodiment of the Invention) FIG. 1 is a block diagram showing an example of a computer system according to a first embodiment of the present invention. The same parts as those of the conventional system shown in FIG. And detailed description thereof will be omitted.

This computer system is provided with each host 2 # 1,
Except for the diagnostic function units 8 # 1 and 8 # 2 provided in 2 # 2 and the inter-client communication function unit 9 provided in the display server 3, the configuration is the same as the conventional system in FIG.

Each diagnostic function section 8 has the same inter-host diagnostic function and conventional host promotion notification function at the time of abnormality detection as well as the inter-client communication function section 9 of the display server 3 is designated to be relayed. It is designed to send diagnostic messages to other hosts.

When the diagnostic function unit 8 receives a diagnostic message from another host that relays the inter-client communication function unit 9, it specifies to relay the inter-client communication function unit 9 of the display server 3. , A reply message is returned to the other host.

Further, when the inter-client communication function unit 9 detects a diagnostic message from the data transmission line 1 for relaying the display server 3 from one host 2 to another host 2, the inter-client communication function unit 9 fetches the message once, and the other host The message is output to No. 2.

Similarly, when a reply message for relaying the display server 3 addressed to a certain host 2 from another host 2 is detected from the data transmission path 1, the message is once taken in and addressed to the host 2 concerned. Is output.

Other configurations and operations are the same as those of the computer system shown in FIG. 3 or the system of multiple hosts which has been supplementarily explained when the system is explained, and therefore its explanation is omitted.

The respective parts of the claims correspond to the above-mentioned configurations as follows. First, the diagnostic means includes, for example, diagnostic function units 8 # 1 and 8 # 2 and an inter-client communication function unit 9.

The online changing means is composed of, for example, the diagnostic function section 8 # 1 or 8 # 2. Next, the operation of the computer system according to the embodiment of the present invention configured as described above will be described.

Here, it is assumed that the online host is the host 2 # 1 and its client process 5 # 1 is the host client. First, the client process 5 # 1 has its display request function unit 6 # 1.
Causes the display function unit 4 of the display server 3 to perform various display outputs.

Next, in order to check whether normal communication is performed between the host 2 # 1 itself and the display server 3, the diagnostic function unit 8 # 2 of the host 2 # 2, which is an offline host, A display server relay diagnostic message addressed to 2 # 1 is output.

The display server relay diagnostic message is received by the inter-client communication function unit 9 of the display server 3. Further, the inter-client communication function unit 9 outputs the display server relay diagnostic message to the host 2 # 1.

The message is received by the diagnostic function unit 8 # 1 of the online host, and the display server 3
It is analyzed that it is a diagnostic message via the, and the diagnostic function unit 8 # 1 outputs the reply message.

That is, the reply message is not directly received by the host 2 # 2, but is relayed once through the inter-client communication function unit 9 of the display server 3 as in the case of the outward path, and then the host 2 # 2. Received at # 2.

When the diagnostic function unit 8 # 2 receives the normal reply message from the online host, the communication between the host 2 # 1 and the display server 3 is normally performed, that is, between the host and the display server. It is determined that the logical connection status is normal, and the client process 5 # 1
Remains a host client.

On the other hand, when the normal reply message from the online host is not obtained, that is, when the response is not received within the fixed time, the diagnostic function unit 8 # 2 uses the client process 5 # 1 which is the online client.
It is determined that the communication between the host 2 # 1 having the above and the display server 3 is not normally performed, that is, the logical connection state between the host and the display server is abnormal.

Then, the diagnostic function unit 8 # 2 causes the client process 5 # 2 which is an offline client.
Will be notified to promote to the host client.

As a result, the display operation on the display server 3 by the client process 5 is continued. Note that the online promotion is performed according to the priority order when there are many hosts 2.

As described above, according to the computer system according to the embodiment of the present invention, the diagnostic function units 8 # 1 and 8 # 2 are used.
For exchanging messages with the client communication function unit 9
Since it is performed via the server, the reliability can be improved by checking the logical connection state between the host and the display server and surely detecting the communication failure between the online host and the display server.

When the online host and the display server are out of communication with each other, the client process 5 of the other host 2 is switched so as to become an online client. Therefore, even if a failure occurs in the online host, the display by the client process 5 occurs. The screen display of the server can be surely continued.

In the present embodiment, the host-
Although the diagnostic function unit 8 provided in the host 2 is used to check the logical connection state between the display servers,
The present invention is not limited to this, and the diagnostic message may be output directly from the display server, for example. (Second Embodiment of the Invention) FIG. 2 is a block diagram showing an example of a computer system according to a second embodiment of the present invention. The same parts as those of the computer system shown in FIGS. 1 and 3 are the same. The reference numerals are given and detailed description is omitted.

The constituent elements of each part constituting this computer system are the same as those in the first embodiment. However, the arrangement of the configuration is different. That is, in this embodiment, the diagnostic function units 8 ′ # 1 and 8 ′ # 2 are configured inside the client processes 5 # 1 and 5 # 2.

The operation itself of each of the diagnostic function units 8 '# 1 and 8'# 2 is the same as that of the diagnostic function units 8 # 1 and 8 # 2 of the first embodiment except for the destination designation of a message described later. is there.

However, as described in the prior art, client processes 5 # 1 and 5 # which are the same process.
2 is only one of a plurality of types of client processes (not shown), and each host 2 has a client process 5
There are many client processes other than.

Therefore, the diagnostic function unit 8'is provided in all of the client processes other than the client process 5. As a result, when the diagnostic function units 8 ′ # 1 and 8 ′ # 2 output the diagnostic message or the reply message, the final destination is not the diagnostic function unit 8 ′ in the target host 2 but the target host 2 Corresponding to the same client process 5
The diagnostic function unit 8'is provided.

The inter-client communication function unit 9'provided in the display server 3 shown in FIG. 2 handles the destination of the above-mentioned message in the same manner as the diagnostic function unit 8 ', and the inter-client communication function unit 9 shown in FIG. It operates similarly to.

Other configurations and operations are the same as those of the computer system shown in FIGS. 1 and 3 or the system of multiple hosts which is supplementarily explained when the system is explained.
The description is omitted.

The respective parts of the claims correspond to the above-mentioned configurations as follows. First, the diagnostic means includes, for example, diagnostic function units 8 ′ # 1 and 8 ′ # 2 and an inter-client communication function unit 9 ′.

The online changing means is composed of, for example, the diagnostic function unit 8 '# 1 or 8'# 2.
Next, the operation of the computer system according to the embodiment of the present invention configured as described above will be described.

Here, it is assumed that the online host is the host 2 # 1 and its client process 5 # 1 is the host client. First, the client process 5 # 1 has its display request function unit 6 # 1.
Causes the display function unit 4 of the display server 3 to perform various display outputs.

Next, in order to check whether normal communication is performed between the client process 5 # 1 itself and the display server 3, the diagnostic function unit 8 '# 2 of the client process 5 # 2, which is an offline client, is checked. Due to
A display server relay diagnostic message addressed to the client process 5 # 1 is output.

The display server relay diagnostic message is received by the inter-client communication function unit 9'of the display server 3. Further, the inter-client communication function unit 9'outputs the display server relay diagnostic message to the client process 5 # 1 of the host 2 # 1.

The message is received by the diagnostic function unit 8 '# 1 of the online client, is analyzed as a diagnostic message via the display server 3, and the diagnostic function unit 8'# 1 outputs the reply message. To do.

That is, the reply message is not directly received by the client process 5 # 2, but is relayed once through the inter-client communication function unit 9'of the display server 3 as in the case of the forward path, and then the client Received in process 5 # 2.

The diagnostic function unit 8 '# 2, which has received the normal reply message from the online host, indicates that the communication between the client process 5 # 1 and the display server 3 is normally performed.
It is determined that the logical connection state between the display servers is normal, and the state in which the client process 5 # 1 is the host client is continued.

On the other hand, when the normal reply message from the online host is not obtained, that is, when the response is not received within the fixed time, the diagnostic function unit 8 '# 2 determines that the client process 5 # which is the online client.
It is determined that the communication between 1 and the display server 3 is not normally performed, that is, the logical connection state between the client process and the display server is abnormal.

Then, the diagnostic function unit 8 '# 2 causes the client process 5 # which is an offline client.
2, that is, in this case, the display request function unit 6 # 2 is notified so as to be promoted to the host client.

As a result, the display operation on the display server 3 by the client process 5, that is, the display request function unit 6 # 2 is continued. The online promotion is performed according to the priority order when there are a large number of hosts 2 and at least some of them have the same client process 5.

As described above, according to the computer system according to the embodiment of the present invention, the diagnostic function units 8 '# 1 and 8'
Since the message exchange with # 2 is performed via the inter-client communication function unit 9 ', the logical connection state between the client process and the display server is checked to check the communication failure between the online client and the display server. The reliability can be improved by surely detecting.

When the online client and the display server are out of communication with each other, the other client process 5 is switched so as to become the online client. Therefore, even if the online client fails, the screen of the display server by the client process 5 is displayed. The display etc. can be surely continued.

Further, in the present embodiment, the diagnostic function unit 8'provided in the host 2 is used to check the logical connection state between the client and the display server, but the present invention is not limited to this. Alternatively, the diagnostic message may be output directly from, for example, the display server.

In each of the above-mentioned embodiments, the display server 3 handles screen display control and the like, but the present invention is not limited to this, and other output devices may be used instead of the display server. For example, a printer or the like may be used. Furthermore, the present invention is not limited to the above-mentioned respective embodiments, and can be variously modified without departing from the gist thereof.

[0073]

As described above in detail, according to the present invention, the message exchange between the hosts is performed via the display server. Therefore, the logical connection state between the host and the display server is checked, and the online host and the display server are connected. It is possible to provide a computer system that improves reliability by surely detecting a communication failure between the two.

Further, since the message exchange between the client processes is performed via the display server, the logical connection state between the client process and the display server is checked to surely detect the communication failure between the online client and the display server. As a result, it is possible to provide a computer system that improves its reliability.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a computer system according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing an example of a computer system according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing an example of a conventional computer system.

[Explanation of symbols]

1 ... Data transmission path, 2 # 1, 2 # 2 ... Host, 3 ... Display server, 4 ... Display function unit, 5 # 1, 5 # 2 ... Client process, 6 # 1, 6 # 2 ... Display request function unit , 8 # 1, 8 # 2 ... Diagnostic function section, 9 ... Inter-client communication function section.

Claims (2)

[Claims] 1. A network connecting a plurality of host computers and at least one display server,
Further, among the client processes that control the output to the display server, the same client process is provided in at least two or more host computers of each host computer, and any one of the same client processes becomes an online client. In a computer system in which, while controlling output to the display server, other same client processes become offline clients and do not execute at least output control operation to the display server, a host having the online client A computer having the online client by exchanging messages between the computer and the host computer having the offline client via the display server. A diagnostic means for determining whether communication between the storage computer and the display server is possible, and a standby state when the diagnostic means determines that the host computer having the online client and the display server are out of communication. And an online changing means for promoting any of the offline clients to an online client. 2. A plurality of host computers and at least one display server are connected by a network,
Further, among the client processes that control the output to the display server, the same client process is provided in at least two or more host computers of each host computer, and any one of the same client processes becomes an online client. In the computer system in which while controlling the output to the display server, other same client processes become offline clients and do not execute at least the output control operation to the display server, each of the same client processes The online client and the display by exchanging messages between the online client and the offline client via the display server. Diagnostic means for determining whether communication with the server is possible, and if the diagnosing means determines that the online client and the display server are in a non-communication state, one of the offline clients on standby is brought online. A computer system comprising an online changing means for promoting to a client.