JP2001273270A - Service provision maintaining method and distributed object system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a service provision maintaining method and a distributed object system using the same, with which the provision of a service can be maintained even when a fault or the like occurs in an object to provide the relevant service. SOLUTION: Concerning the service provision maintaining method for the service to be provided by each of objects operated on plural distributively located controllers, the state of the service provided by the object is monitored and when the service provided by the first object is stopped, the provision of the service is substituted by the second object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed object system in which a plurality of objects are distributed in a plurality of control devices, and more particularly, when a failure occurs in an object providing a certain service, the provision of the service is maintained. And a distributed object system using the same.

[0002]

2. Description of the Related Art In a conventional distributed object system in which a plurality of objects are distributed and arranged on control devices such as a plurality of computers, a client who wants to use a service provided by such an object determines which object It is necessary to ask individual objects whether such services are provided.

For this reason, services that can be supplied by each object are registered in a specific server, and a client searches for necessary services from the registration information of the server, and performs processing and the like on the objects that provide the necessary services. By requesting, the service was easily provided.

FIG. 7 is a configuration block diagram showing an example of such a conventional distributed object system. In FIG. 7, reference numeral 1 denotes a control device (hereinafter, simply referred to as a server) which is a server for managing service registration from each object.
Reference numerals 2, 3 and 4 denote control devices (hereinafter simply referred to as hosts), which are hosts on which objects operate in a distributed manner. Reference numeral 5 denotes a control device (hereinafter, simply referred to as a client) which is a client machine which receives a service. And 6 are storage means for storing registered service information as a naming table.

[0005] The servers 1 are alternately connected to storage means 6,
The server 1, the hosts 2 to 4 and the client 5 are LAN,
They are interconnected by communication lines such as WAN and public lines.

Here, the conventional example shown in FIG. 7 will be described with reference to FIG. FIG. 8 is an explanatory diagram showing an example of the naming table stored in the storage means 6. "NS01" in FIG.
Operates on the server 1 and registers and manages information registered from each object in the storage unit 6.

In FIG. 7, "OB01" and "OB02"
The objects indicated by “OB03” and “OB03” operate on the hosts 2, 3 and 4, respectively, and request the registration of services that can be provided by the name server indicated by “NS01” in FIG.

For example, "OB01" and "OB0" in FIG.
It is assumed that the services that can be provided by the objects indicated by “2” and “OB03” are “service β”, “service γ”, and “service α”.

[0009] The name of the object providing the service and the name of the host on which the object operates are added to such service contents and registered in the naming table stored in the storage means 6 for management.

For example, as shown by "ND01" in FIG. 8, "OB03" which is an object name for providing the service and "Host 4" which is a host name on which the object operates are added to "service α". Registered.

[0011] Similarly, as shown by "ND02" in FIG. 8, "service β" is added with "OB01" which is an object name for providing the service and a host name "host 2" on which the object operates. It is registered.

Also, as shown by "ND03" in FIG.
The service γ is registered by adding an object name “OB02” that provides the service and a host name “host 3” on which the object operates.

As described above, when the naming table stored in the storage means 6 is completed, the client 5 determines whether or not the service which the client 5 intends to use is provided by this distributed object system, "NS0" in FIG.
Inquiry to the name server indicated by 1 ".

The name server having received the inquiry searches the registration information of the naming table stored in the storage means 6 for the service which the client 5 intends to use, and finds the name of the object providing the service and the object. The operating host name is notified to the client 5.

Then, the client 5 receiving the notification
Requests the service of the notified object, and the object provides the client 5 with the requested service.

For example, in order to use “service α”, the client 5 transmits the message “IQ01” as shown in FIG.
An inquiry is made to the name server indicated by the middle “NS01” as to whether “service α” is provided.

The name server searches the naming table stored in the storage means 6, and as shown by "RS01" in FIG. 7, the object name "OB03" and the object "OB03" providing the "service α". Is notified to the client 5 of the host name "host 4" on which the server operates.

The client 5 that has received the notification such as “RS01” in FIG. 7 responds to the object “OB03” operating on the host 4 with “service α” as indicated by “RQ01” in FIG. Request to provide an object "
OB03 "provides the requested" service α "to the client 5, as indicated by" SV01 "in FIG.

As a result, each object existing in the distributed object system registers a service that can be provided by itself to the name server, and a client to be provided with a service inquires the name server to obtain a required object name. By obtaining the host name and the host name, it becomes possible to easily use various services of the distributed objects.

[0020]

However, in the conventional example shown in FIG. 7, it is necessary for the service provided by each object to make a registration request to the name server by itself. For this reason, there has been a problem that if the object is stopped for some reason after the service is registered and the host on which the object operates is stopped, the service cannot be provided to the client. Therefore, an object of the present invention is to provide a service provision maintaining method capable of maintaining the provision of a service even when a failure or the like occurs in an object providing the service, and a distributed object system using the same. It is to realize.

[0021]

In order to achieve the above object, according to the first aspect of the present invention, a service provided by each object operating on a plurality of distributed control devices is provided. In the service provision maintaining method, by monitoring a state of the service provided by the object and, when the service provided by the first object is stopped, by providing the second object with the service provided by the second object, Even if a failure or the like occurs in the object, the provision of the service can be maintained.

According to a second aspect of the present invention, there is provided a service providing / maintaining method of a service provided by each object operating on a plurality of distributed control devices, wherein a state of the service provided by the object is monitored by the first method. When the service provided by the first object operating on the control device of the above is stopped, by activating the first object on the second control device to provide the service, the object is provided. Even if a failure or the like occurs, provision of the service can be maintained.

According to a third aspect of the present invention, there is provided a service providing and maintaining method according to the first and second aspects of the invention.
Based on information such as what service each of the objects can provide and on which control device in the control device it is possible to determine whether to provide the service or to activate the first object. This makes it possible to maintain the provision of the service even when a failure or the like occurs in the object.

According to a fourth aspect of the present invention, there is provided a service providing and maintaining method according to the first and second aspects of the invention.
By determining that the service provided by the object has stopped when an operation report from the control device on which the object operates cannot be confirmed for a certain period of time,
Even if a failure or the like occurs in the object, the provision of the service can be maintained.

According to a fifth aspect of the present invention, there is provided a distributed object system in which a plurality of objects are distributed and arranged in a plurality of control devices, wherein first and second objects for providing services operate respectively. And a third control device that monitors the state of the service and, when the service provided by the first object is stopped, causes the second object to substitute for the provision of the service. This makes it possible to maintain the provision of the service even when a failure or the like occurs in the object.

According to a sixth aspect of the present invention, there is provided a distributed object system in which a plurality of objects are distributed and arranged in a plurality of control devices, wherein a first and a second object for providing a service operate respectively. A control device, and, when the service provided by the first object operating on the first control device is stopped, activating the first object on the second control device to execute the service Is provided, the provision of the service can be maintained even when a failure or the like occurs in the object.

According to a seventh aspect of the present invention, in the distributed object system according to the fifth and sixth aspects of the present invention, the third control device determines what kind of service each of the objects can provide. In the case where a failure or the like occurs in the object by determining the alternative of providing the service or activating the first object based on information on which control device in the control device can operate. Can maintain the provision of the service.

According to an eighth aspect of the present invention, in the distributed object system according to the fifth and sixth aspects of the present invention, the third control unit operates the first and second control units on which the object operates. By judging that the service provided by the object has stopped when the operation report cannot be confirmed for a certain period of time, it is possible to maintain the provision of the service even when a failure or the like occurs in the object. Become.

According to a ninth aspect of the present invention, in the distributed object system according to the fifth and sixth aspects of the present invention, the distributed object system operates on the third control device to manage the services of the entire distributed object system. The provision of the global manager makes it possible to maintain the provision of the service even when a failure or the like occurs in the object.

According to a tenth aspect of the present invention, in the distributed object system according to the fifth and sixth aspects, the invention operates on the first and second control devices and operates on the control devices. The provision of the local manager that manages the object providing the service makes it possible to maintain the provision of the service even when a failure or the like occurs in the object.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing one embodiment of a distributed object system according to the present invention. In FIG. 1, reference numeral 6 denotes the same reference numeral as in FIG. 7, 1a denotes a control device (hereinafter simply referred to as a server) which is a server for managing service registration from each object, and 7, 8 and 9 denote objects. A control device (hereinafter simply referred to as a host), which is a host that operates in a distributed manner, is a control device in which a global manager operates, and 11 is a control device that determines which objects can provide what services and which hosts can operate. Storage means for storing information as a configuration table,
100 is a communication line such as a LAN.

The servers 1 a are alternately connected to the storage means 6, and the control device 10 is alternately connected to the storage means 11.
The server 1a, the hosts 7 to 9 and the control device 10 are mutually connected by a communication line 100.

Here, the embodiment shown in FIG. 1 will be described with reference to FIGS.
This will be described with reference to FIGS. 2 and 3 are flowcharts for explaining the operation of the global manager.
5 and FIG. 5 are flowcharts for explaining the operation of the local manager, and FIG. 6 is a flowchart for explaining the operation of the object. However, description of the same parts as those of the conventional example shown in FIG. 7 will be omitted.

A name server indicated by "NS11" in FIG. 1 operates on the server 1a and registers and manages information registered from each object in the storage means 6.

Also, "OB11" and "OB12" in FIG.
The objects indicated by "OB13" and "OB13" operate on the hosts 7, 8 and 9, respectively, and request the name server indicated by "NS11" in FIG.

Further, "LM11", "LM1" in FIG.
The local managers shown as "2" and "LM13" operate on the hosts 7, 8 and 9, respectively, and "GM1" in FIG.
The global manager 1 "operates on the control device 10 and registers and manages a configuration table in the storage unit 11 with information such as which objects can provide what services and which hosts can operate.

The global manager indicated by "GM11" in FIG. 1 is 1 in the entire distributed object system.
And manage services for the entire system. on the other hand,
A local manager indicated by “LM11” or the like in FIG. 1 exists in a host on which an object providing a service is operating and manages an object operating on the host.

In FIG. 2, at "S001", the global manager "GM11" reads the configuration file stored in the storage means 11 and obtains information such as which object can provide which service and which host can operate. get.

Then, in "S002" in FIG. 2, the global manager "GM11" receives the operation report from each local manager existing in each host, and grasps the operation status from the operation report received in "S003" in FIG. And update the content.

For example, the local manager indicated by “LM11” in FIG.
An operation status as to whether or not the object indicated by “1” is operating, the contents of the service provided by the object, and the like are transmitted as an operation report.

If there is a change from the previous operation report, the operation status is updated.

In FIG. 2, in "S004", the global manager "GM11" determines whether or not the object operating on each host is operating normally based on the operation report.

If it is determined that the object is not operating normally, the global manager "GM11" in "S005" in FIG. It requests that the object be restarted.

Further, in the step indicated by "S002" in FIG. 2, the processing is actually performed in the steps as shown in FIG. That is, in "S101" in FIG. 3, the global manager "GM11" determines whether or not an operation report has been received from each local manager, and when an operation report has been received, returns to the step of "S003" in FIG.

On the other hand, if the operation report is not received in "S101" in FIG. 3, the global manager "GM11" cannot receive the operation report in "S102" in FIG. 3 and determines whether a predetermined time has elapsed. And if
If a certain period has elapsed, the local manager determines that the operation has stopped, or the host determines that the operation has stopped.

If the local manager or the like determines that the operation is stopped, the global manager "GM11" extracts the contents of the service provided by the object of the host concerned from the information obtained from the configuration file in "S103" in FIG. I do.

In "S104" in FIG. 3, the global manager "GM11" determines whether or not the service can be replaced by another object. If the service can be replaced, the object can be replaced in "S105" in FIG. To register the service in the naming table.

If the service cannot be replaced in “S104” in FIG. 3, the global manager “GM11” can start the object providing the service in another host in “S106” in FIG. It is determined whether or not there is, and if it can be started, “S1” in FIG.
At 06 ", the local manager of the host that can be activated is requested to activate the object.

For example, when the local manager indicated by “LM11” in FIG. 1 stops operating or the host 7 stops operating, “OB12” and “OB13” in FIG.
It is determined whether or not the service can be replaced by the normally operating object shown in (1). If the object shown in “OB13” in FIG. 1 can be replaced, the object “OB1” can be replaced.
3 "causes the service to be provided.

Also, for example, it is determined whether or not the stopped object indicated by “OB11” in FIG. 1 can operate on another host.
If the object shown in (1) can be activated, the object "OB11" is activated on the host 8 to provide the service.

Such a global manager "GM"
In contrast to the operation of "11", each local manager registers and manages the operation of the object and the provided service in the naming table in "S201" in FIG.

Each local manager transmits a response request to the object managed by itself in "S202" in FIG. 4, and determines whether or not there is a response from the object in "S203" in FIG.

If there is a response from the object, it is determined in step S204 in FIG. 4 that the object is operating. If there is no response from the object, the object is determined in step S205 in FIG. Is determined to be stopped, the registration of the object in the name server “NS11” is deleted, and “S20” in FIG.
At 6 ", the operation status and the like of the object are transmitted to the global manager as an operation report.

When each local manager receives an object restart request from the global manager in "S301" in FIG. 5, "S30" in FIG.
In step 2 ", the corresponding object is restarted.

Finally, the object running on each host registers the service that can be provided in “S401” in FIG. 6 with the local manager (registers the service that can also be provided in the name server “NS11”). . Then, in "S402" in FIG. 6, the object determines whether or not there is a response request from the local manager.
If there is a response request, a response is transmitted to the local manager in "S403" in FIG.

As a result, the local manager of each host monitors the objects running on the host, the global manager manages the entire system, and if a failure occurs in the object providing the service, the other managers By making an object substitute for a service or activating an object to another host to provide a service, even if a failure or the like occurs in the object, the provision of the service can be maintained.

In the embodiment shown in FIG. 1, a distributed object system is described as an example, but the present invention can be applied to an agent-based production system.

In the description shown in FIG. 1, for simplicity, the control device in which the global manager operates and the control device in which the name server operates are described separately. A name server may be operated.

In the description shown in FIG. 1, the storage means for storing the configuration file and the storage means for storing the naming table are separately described for simplicity. Of course, the configuration file is stored in one storage means. And a naming table may be stored.

[0060]

As is apparent from the above description,
According to the present invention, the following effects can be obtained. According to the first to tenth aspects of the present invention, the state of the service provided by the object is monitored, and if a failure or the like occurs in the object providing the service, the service is replaced by another object. By activating an object to another host to provide a service, even if a failure or the like occurs in the object, the provision of the service can be maintained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of a distributed object system according to the present invention.

FIG. 2 is a flowchart illustrating the operation of a global manager.

FIG. 3 is a flowchart illustrating an operation of a global manager.

FIG. 4 is a flowchart illustrating the operation of a local manager.

FIG. 5 is a flowchart illustrating the operation of a local manager.

FIG. 6 is a flowchart illustrating the operation of an object.

FIG. 7 is a configuration block diagram showing an example of a conventional distributed object system.

FIG. 8 is an explanatory diagram showing an example of a naming table stored in a storage unit.

[Explanation of symbols]

1,1a, 2,3,4,5,7,8,9,10 Control device 6,11 Storage means 100 Communication line

Claims (10)

[Claims] 1. A service provision and maintenance method for a service provided by each object that operates on a plurality of distributed control devices, wherein a state of the service provided by the object is monitored to provide the first object. A service provision maintaining method, wherein when the service is stopped, the second object replaces the provision of the service. 2. A service providing and maintaining method for a service provided by each object which operates on a plurality of distributed control devices, wherein a state of the service provided by the object is monitored and the first control device monitors the status of the service. A service provision maintaining method, characterized in that when the service provided by the first operating object is stopped, the first control unit activates the first object to provide the service. 3. An alternative to the provision of the service or the first object based on information on what kind of service each object can provide and on which control device in the control device. 3. The method according to claim 1, further comprising:
The service provision maintenance method described. 4. The system according to claim 1, wherein the service provided by the object is determined to have stopped when an operation report from the control device on which the object operates cannot be confirmed for a certain period of time. Service provision and maintenance method. 5. In a distributed object system in which a plurality of objects are distributed and arranged in a plurality of control devices, first and second control devices on which first and second objects for providing services operate, respectively; And a third control unit that monitors a state of a service and, when the service provided by the first object is stopped, causes the second object to substitute for the provision of the service. Object system. 6. A distributed object system in which a plurality of objects are distributed and arranged in a plurality of control devices, wherein a first and a second control device on which first and second objects for providing a service operate, respectively, A third method that activates the first object on the second control device to provide the service when the service provided by the first object operating on the first control device stops; A distributed object system comprising a control device. 7. An alternative to providing the service, based on information on what service each of the objects can provide and on which control device in the control device the third control device can provide the service. 7. The distributed object system according to claim 5, wherein the activation of the first object is determined. 8. The third control device determines that the service provided by the object has been stopped when an operation report from the first and second control devices on which the object operates cannot be confirmed for a certain period of time. 7. The distributed object system according to claim 5, wherein 9. The distributed object system according to claim 5, further comprising a global manager that operates on said third control device and manages the service of the entire distributed object system. 10. A local manager which operates on the first and second control devices and manages the object which operates on the control devices and provides a service. 7. The distributed object system according to claim 5 or claim 6.