JPH10187467A - Remote procedure call processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the change processing of group constitution and to enable early detection concerning a remote procedure call(RPC) processing system for calling a group server. SOLUTION: When adding a server to a server group 80, an additional report is outputted from a group constitution change reporting part 70 to a processor provided with a server in the group such as a processor 5, for example. An RPC processing part 50, which receives this report, holds group constitution change information reporting the addition of new procedure. An RPC request source such as a client 15 of processor 2, for example, issues the RPC request of 'QSORT' to servers 25, 35 and 45 in the server group 80 and correspondent servers in the group are respectively executed. When executing a server 421 and transmitting the executed result to the request source, the processor 5 adds this group constitution change information. When any change in group constitution is detected out of a response message, an RPC processing part 10 at the request source updates its own address information by calling all the address information from an address managing part 60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication processing technique used in a distributed processing system, and more particularly, to a request / response communication.
In particular, the present invention relates to a method of processing a remote procedure call (hereinafter abbreviated as RPC), and more particularly to a method of changing the configuration of a server group in a system having a group of servers.

[0002]

2. Description of the Related Art RPC is particularly established as a communication technique in a client-server system, and performs one-to-one request / response communication from a client to a server. For example, in a distributed processing system in which a plurality of information processing apparatuses are connected to each other via a network, a client existing in one processing apparatus uses another processing apparatus in the same manner as a procedure call existing in its own processing apparatus. Calls a procedure provided by the server that exists in the server, and receives the execution result. Representative RP
C is OSF (Open Software Foundation) D
There is an application example in CE (Distributed Computing Environment). Hereinafter, this example is referred to as DCE / RPC.

In DCE / RPC, an application server called a directory server manages all address information existing in a distributed processing system. The client queries this directory server to obtain the address information of the server to be called, and
The server of this address information is called by the PC. DC
In E / RPC, when a new server is added to a distributed processing system, first, its own address information is registered in a directory server so that a client can refer to the address of the server.

[0004]

In a conventional PRC processing technique such as DCE / RPC, a client can detect addition of a new server only by searching a directory server. For this reason, when servers that perform the same processing are grouped into a multiplexed server and a client accesses all servers in the group (such as dual multiplexing), it becomes difficult to add a server online.

That is, online addition requires that all clients always search the directory server, which increases the load on the network, the directory server, and the clients. As a result, when the access throughput to the directory server decreases, the RP to the server group is reduced.
Processing of C also becomes slow.

In this case, if the search cycle of the directory server is lengthened to reduce the load, the configuration of the multiplexing server is improper, such that a certain client can call an additional server and another cannot be called depending on the timing. It will be consistent. For example, if the multiplexed file or the multiplexed database is inconsistent, the reliability of the RPC process and thus the system is significantly reduced.

[0007] A method is conceivable in which the change of the server is immediately transmitted to all clients using broadcast communication. For this purpose, the client must always be ready for reception from the network, and the memory and machine load increase. In general, in a client-server system, a computer having relatively low processing capacity is often used on the client side, and the load on the computer is large. Further, there is no guarantee that the transmission by the broadcast is always received, and there is a possibility that a message may be missing or the client may not receive the change information of the server. For example, when the client is inoperable, the change information is not reflected.

An object of the present invention is to provide a remote procedure call processing method or a communication method that allows a client to immediately detect a change in the configuration of a server group by a plurality of servers without increasing the load, in view of the problems of the prior art. Is to do.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to provide a remote procedure call processing method for calling a plurality of grouped servers in response to a request for one remote procedure call. Any server belonging to the server group holds the change information of the change server to be added or deleted, and this server returns an execution result corresponding to an execution request issued from each remote procedure call request source to the request source. Sometimes, this is achieved by adding the change information to the execution result.

The change of the server group is notified to any one of the groups, and the server receiving the change holds the change information, and returns the execution result of the procedure to the request source as a response message to the request source. Is added. On the other hand, the request source changes the member of the server group to be called by itself based on the change information.

[0011] The requesting source previously holds the address information of the server group to be called by itself and the current change information, compares the change information of the response message with the change information held by itself, and when the difference is different, the request source itself. Change group information.

Alternatively, the remote procedure call request source adds each procedure execution request and the held current change information to a request message to be transmitted to each server in the group, and the server that has received it adds the request to the server of the procedure. When the execution result is returned to the request source as a response message, if the change information held by itself and the change information of the request message are different, a group configuration change flag is set. When the change flag is set in the response message, the requester changes the member of the server group to call.

As another invention, one of the members of the server group is called on behalf of a server arbitrarily selected by a remote procedure call requester, and the called representative server executes its own processing, In the remote procedure call processing method for duplicating the content requested by the request source and calling the server of the remaining members, the server that receives the notification of the change in the group configuration and holds the change information includes: When a request to execute a procedure is issued to the representative server, and when the content of the request for copying is transferred from the representative server, a response message in which the change information is added to the execution result of the procedure execution is returned to the representative server, The representative server calls the members of the server group to call based on the change information. And changes Te.

When the representative server changes the member, the representative server updates the change information held by itself, and sends a response message including the change information and the execution result of each server in the group to the remote procedure call request source. . The request source compares the change information of the response message from the representative server with that held by itself, and changes its own group information when the information is different.

In the above, before any one of the server groups is notified of the change in the group configuration, the address of the change server is registered or deleted from the name server that manages the address of the server in the system, and When the procedure call request source or the representative server receives the change information, it acquires address information from the name server and changes a member of a server group to be called by itself.

When the members of the server group are changed, constraints on the group configuration are checked based on the identifiers for identifying the processing contents of the procedures provided in the respective servers, and it is determined whether the members can be changed. For example, when there is a restriction on addition or deletion of a certain identifier within a group, addition or deletion exceeding the limit is prohibited.

The server is a program provided as a procedure. Alternatively, it is a program that executes its own process in accordance with the execution request and returns the result to the request source, or does not return the result.

According to the configuration of the present invention, the RPC process performed between the client and the server has a function of detecting a server group configuration change and automatically changing the server. Can be automated, such as collecting information necessary for the client to change the called server and controlling the timing of reflecting this information to all clients.

According to this, a server having the same function as an existing server can be added to the multiplex server group, and the degree of multiplex of the multiplex server can be varied online. Alternatively, a new server is added to the server group, and each remote procedure request source that has detected the addition of the new server specifies one of the server that has been the processing request destination up to this time and the new server as the new processing request destination. And the processing performed by the procedure executing side can be load-balanced among the servers in the group. Alternatively, a new version of a new server is added to the server group, and each remote procedure execution request source that has detected the addition of the new server requests the new server in place of the server that has been the process request destination up to this point. You can switch to the first and upgrade online.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. The first embodiment shows an RPC process including a change of a server group, the second embodiment shows an alternative in which the server performs the change process, and the third embodiment shows an alternative using the indirect multicast method. Further, the fourth embodiment shows an example in which the change of the server group is processed by the request response communication instead of the RPC, and the same reference numerals are given to the same elements in principle throughout the drawings.

[Embodiment 1] FIG. 1 is a functional block diagram of a distributed system using RPC according to an embodiment of the present invention. The processing devices 2 to 8 are connected to the communication medium 1 and communicate with other processing devices. As the communication medium 1, L
AN (Local Area Network) and WAN (WideArea Netwo)
rk) or a wireless (wireless) communication line. Although the bus type is shown as an example, various networks such as a duplex bus type, a single loop type, a double loop type, and a ring type can be used. First, a configuration of a distributed system using RPC will be described, and then a process of changing a group configuration will be described using an example of adding a processing device to a group.

The processing device 2 includes a client and an RPC processing unit, and requests execution of processing to another processing device using RPC. Processing devices 3 to 6 are server and RP
It has a C processing unit 20, executes processing requested by another processing device, and returns the result to the request source. The processing devices 3 to 5 are grouped to form a multiplexing server 80.

The client 15 of the processing device 2 includes a user program created or used by a user,
An application program or the like that requests a procedure of a server provided to another processing device to refer to information necessary for processing. Client 1
5 requests the execution of a server procedure,
A request is issued to the RPC processing unit 10.

The RPC processing unit 10 performs the RPC request processing of the client 15. The RPC processing unit 10 receives the RPC request issued from the client 15, transmits a procedure execution request of the server as an RPC request message to another processing device, and outputs a procedure execution result corresponding to the RPC request message transmitted by itself. Attached RP
C receiving the response message and requesting the client 15
It has a function to return to.

The processing device 3 includes an RPC processing unit 20 and a server 25, executes a process requested by another processing device, and returns the result to the request source. RPC processing unit 2
0 receives the RPC request message transmitted from another processing device, executes the procedure of the server requested to execute, and transmits an RPC response message with the execution result to the requesting processing device.

The server 25 is a program that executes itself in response to a request from the RPC processing unit 20 and returns the execution result to the RPC processing unit 20, and is provided in the form of a procedure. The server 25 is a program created or used by a user, and is a program that provides information necessary for processing by a client.

In the system, a plurality of servers corresponding to the purpose and application exist in various combinations. Each server is provided with a processing identifier indicating what kind of processing the server itself performs, and the processing contents are identified.
As the processing identifier, for example, the procedure name of the procedure provided by the server, or the I that uniquely identifies the procedure
Use a D number or the like. The illustrated server 25 includes a server 401 whose processing identifier is “QSORT” and a server “ASOR”.
T ”server 402 and“ BSORT ”server 403
It is included.

The processing devices 4 to 6 have the same configuration as the processing device 3 and include servers 35, 45, 55 and RPC processing units 30, 40, 50, respectively. RPC processing unit 30,
40 and 50 have the same function as the RPC processing unit 20. The server 35 is, similarly to the server 25, a server 4
11 to 413. The servers 45 are the servers 421 and 4
22 and a server 423 whose identifier is “CSORT”. Further, the servers 55, 432, and 433 that are the same as the server 45
It is included.

The processing device 7 includes an address management unit 60, and manages addresses of the processing devices 3 to 6 including servers existing in the system. The address management unit 60 performs addition, deletion, or reference processing of address information in response to a request from another processing device, and returns a processing result to a request source.

The processing unit 8 includes a group configuration change notification unit 7
0, and receives a request to change the configuration of the server group, that is, to add or delete a server to the server group 80, by a command input or the like from the user,
The server notifies the server of the server group 80 of the event.

In the present embodiment, a remote procedure call processing method according to the present invention will be described by taking as an example a process of adding a server 55 to a server group 80 including servers 25, 35, and 45. Although there are various methods for grouping servers, in this embodiment, servers having the same processing identifier are treated as one group. In this case, it is not necessary that all servers in the same group perform exactly the same processing, and the processing contents may be different as in the example of FIG.

Next, RPC to the grouped servers is performed.
An outline of the processing will be described. Client 15 uses R
A procedure execution request is transmitted to the server group 80 via the PC processing unit 10. However, the RPC processing unit 10
Determines a server group that can process the RPC request issued by the client 15 and a server belonging to the RPC request, and transmits an RPC request message to all the processing apparatuses including the server. This judgment is
When the client 15 issues an RPC request to the RPC processing unit 10, the request is performed based on the processing identifier passed from the client 15.

Of the processing devices in the server group 80,
RPC of each processing device that received the RPC request message
The processing unit executes a server capable of executing the requested process, and transmits the execution result to the requesting processing device 2 as an RPC response message. RPC processing unit 10 of the request source
Receives an RPC response message from each processing device that has transmitted the RPC request message, selects one RPC response message from the received RPC response messages based on a predetermined logic, and executes an execution result of a server included therein. Is returned to the client 15. As the logic used for this selection, logics such as "select one randomly", "select one based on majority logic based on the response content", and "select the earliest one" are used. be able to.

Next, the format of the RPC message transmitted between the processing units will be described. FIG. 2 shows a format of an RPC message for notifying a server group configuration change. Server change notification RPC message 10
0 is transmitted from the group configuration change notification unit 70,
C control header section 101 and change server processing identifier section 103
It consists of. The RPC control header 101 stores information necessary for controlling processing involved in transmitting and receiving an RPC request message and an RPC response message. The RPC request content identifier unit 102, which is a part of the area, stores a process identifier by which the RPC processing unit on the receiving side can identify the process content requested by RPC. It also has an area for storing a destination address, a source address, a transmission serial number, request / response identification information, and the like. Change server processing identifier part 1
03 stores, for example, a processing identifier representing the processing content of the server 55 added to the server group 80.

FIG. 3 shows a format of the RPC request message. The RPC request message 110 is transmitted by the RPC processing unit 10 in response to the RPC request of the client 15 and includes an RPC control header unit 101 and a client request data unit 111. The client request data section 111 stores input / output arguments of a server procedure for executing the server.

FIG. 4 shows a format of the RPC response message. The RPC response message 120 is
The PC processing units 20 to 50 transmit the execution result of the server of the own processing apparatus to the client, and include an RPC control header unit 101, a server execution result data unit 122, and a group configuration change serial number unit 121. The server execution result data section 122 stores the server execution result. The group configuration change serial number unit 121 is unique to this embodiment,
A group configuration change serial number that is incremented each time the configuration of a server group is changed, such as when a server is added, is stored.

The group configuration change serial number (hereinafter, referred to as a change serial number) is a change serial number which is independently managed by each processing device having a server. One processing apparatus holds one corresponding change serial number for each group to which the server of the processing apparatus belongs. In order to manage the change history of the server group, a change serial number for each type corresponding to the type of the configuration change such as addition or deletion of a server may be prepared.
In the present embodiment, a notification RPC for adding or deleting a server
When the message 100 is received, the change serial number is incremented as described later.

On the other hand, as described later, the RPC requesting side holds change serial numbers of all servers of the target server group that issues the RPC request in advance. Then, when the RPC response message 120 is received, the change serial number stored in the message is compared with the held change serial number, and a change in the server group is detected by a mismatch between the change serial numbers.

The outline of the system configuration and the message format have been described above. Next, a detailed configuration of a system for executing the remote procedure call according to the present embodiment and a process of each unit will be described. The RPC processing units included in the processing devices 1 to 6, the address management unit 60 included in the processing device 7, and the group configuration change notification unit 70 included in the processing device 8 will be described in this order.

FIG. 5 shows a detailed configuration of the processing apparatus. The illustrated processing device 2 is an example, and other processing devices 3
-8 may have the same configuration. The processing device 2 is R
The client 15 and the server 16 together with the PC processing unit 10
It has both. The RPC processing unit 10 includes an RPC client processing unit 11, an RPC server processing unit 12, an address management table 13, and a group management table 14. The address management table 13 stores information on servers in which each processing device belongs to a server group. The address management table 13 stores a processing identifier representing the processing content of a server and the address of a processing device having the server.

If the processing device is dedicated to client processing, the server 16 and the RPC server processing unit 12 are not required. When the processing device is dedicated to server processing, the client 15 and the RPC client processing unit 11 are unnecessary, and in the case of the present embodiment, the address management table 13 is also unnecessary.

Further, a plurality of RPC processing units may be provided to share RPC processing from clients and servers.
In this case, the destination address when the RPC request message is sent from another processing device is the address of the RPC processing unit in charge of processing of the destination server (for example, the address of this processing device and the receiving port number of this RPC processing unit). It may be.

FIG. 6 shows the structure of the address management table. The RPC processing unit 10 requests the address management unit 60 to acquire information that is composed of a process identifier unit 131 and an address unit 132 and that is stored in each of them. The figure shows a part of the configuration in FIG. 1 and stores address information of at least three processing devices. That is, "QSORT"
There are three processing devices having a server identified by, and each address is “133.144.8.159:8080” and “133.144.8.160:805”.
2 "and" 133.144.8.161:8031 ". Further, there is a processing apparatus having a server identified by “ASORT”, and its address “133.144.9.120:6198” is stored. As the address, a set of an IP address and a receiving port number is used as shown.

FIG. 7 shows the structure of the group management table. The group management table 14 stores the configuration information of each processing device for a server group. As shown in the figure, the information processing system includes a process identifier section 141, an address section 142, and a group configuration change serial number section 143, and these three pieces of information are used as a set. In the process identifier section 141 and the address section 142, similarly to the address management table 13, a process identifier representing the processing content of the server and the address of the processing device are stored.

The group configuration change serial number section 143 stores a change serial number for managing a change in the configuration of the server group. FIG. 7A shows a part of the group configuration shown in FIG. 1, in which there are three processing apparatuses having servers identified by “QSORT”, and the group configuration change serial numbers are “2” and “2”, respectively. "3" and "5". Also, "AQ
There is at least one processing device having a server identified by "ORT", and its group configuration change serial number is "2". Here, the change serial numbers “2” and “3” for the same QSORT reflect the number of changes in the processing device corresponding to the address.

FIG. 8 is a flowchart showing the processing of the RPC client processing unit. The RPC client processing unit 11 performs processing on behalf of the RPC request from the client 15.

First, an RPC request is received from the client 15 (S101). At this time, the processing identifier of the server requesting the processing and the arguments required for the processing are passed from the client 15 to the RPC client processing unit 11.

Next, the address management table 13 is searched in order to obtain the address of a processing device having a server that can execute the RPC request. At this time, nothing is registered in the address management table 13 with the first RPC request. If not (S102), the address management table 13 is initialized (S103).

FIG. 9 is a flowchart showing the initialization processing S103. The RPC client processing unit 11 transmits to the address management unit 60 an RPC request message requesting reference to all addresses corresponding to the processing identifier stored in the address management unit 60, and address information attached to the response message Is acquired (S1031). This address information is registered in the address management table 13 (S1032), and an address is similarly registered in the group management table 14, and "0" is set to the corresponding group configuration change serial number (S1033).

Next, the RPC client processing section 11
The address management table 13 is searched to obtain the addresses of all the processing devices including the server that can execute the RPC request (S104), and the number of the processing devices is counted (S105). This search is performed using the process identifier passed from the client 15 as a key, and the addresses of all the processing devices having the same process identifier as the process identifier passed from the client are acquired from the address table 15. Then, the request message is transmitted to one server of the server group (S106). That is, the client request data portion 111 of the PRC request message 110
Into the processing device given by the address acquired in S104, and
A PC request message 110 is transmitted.

When the addresses of a plurality of processing devices are obtained as a result of the address search in S104, it is necessary to transmit the RPC request message 110 to all the obtained processing devices. Therefore, after transmitting the RPC request message 110, the number of processing devices that have transmitted the message is counted (S107), and the count value is compared with the number of servers in the acquired server group (S11).
0). If the result of the comparison indicates that the count value is smaller, S
From the addresses acquired in the process of step 104,
An address to which the request message 110 has not been transmitted is selected (S111), and the RPC request message 110 is transmitted. As described above, by repeating the transmission processing from S106 to S111, the RPC belonging to the server group
RPCs are sent to all servers corresponding to the processing identifier of the request.
Send a request message 110.

The above is the process of transmitting an RPC request from a client. When transmitting the RPC request message 110, a response message is returned from the server of the RPC request destination. The RPC client processing unit 11 checks the reception of a response message from the server of the RPC request destination (S108), and performs a response reception process as follows (S109).

FIG. 10 shows a flowchart of the response receiving process (S109). RPC client processing unit 11
Receives the response message 120 (S201),
From the response message 120 (FIG. 4), the address of the message source, the RPC request content identifier, and the group configuration change serial number are obtained (S202). Then, it searches its own group management table 14 to detect address information that matches both the address attached to the response message and the RPC request content identifier, and determines the change serial number of the address information and the change serial number by the response message 120. A comparison is made (S203).

As a result of the comparison, if the two values are the same, it is determined that the server group has not been changed, and the response receiving process ends. On the other hand, if the value of the change serial number in the response message 120 is large, that is, if the value has been incremented, it is determined that the server group has been changed (S2).
04), the group configuration change serial number based on the response message 120 is stored in the group configuration change serial number section 143 of the address information of the group management table 14 (S205).

Next, the RPC client processing section 11 is connected to the address management section 6 of the processing device 7 via the network 1.
In step S206, an RPC request message referring to the addresses of all the servers is transmitted, and address information attached to the response message is obtained. Next, the acquired address information is compared with the contents of the address management table 13 of the user, and the difference remaining in the former is acquired as the address of the additional server (S207).

Here, the address information acquired from the address management unit 60 is a set of a set of a process identifier and an address corresponding to the process identifier. The same applies to the address management table 13. The comparison is performed on the tuples, which are members of both sets,
Find the difference. The reason why the address management table 13 is provided in addition to the group management table 14 is to simplify the difference processing. In the case of a change for deleting a server, the difference information remaining on the address management table 13 of the own server becomes the address of the deleted server.

Next, in this embodiment, the address information of the processing device having the additional server acquired in S207 is added to the address management table 13 (S208). Further, the same is added to the group management table 14, and the initial value “0” is stored in the corresponding group configuration change serial number at this time (S209).

The above is the response receiving process (S109). If a plurality of addresses are obtained in S104, the RP
Since a plurality of C request messages are transmitted, the same number of response messages are returned. Therefore, RPC
The client processing unit 11 repeats the response receiving process until all the response messages are received (S112),
One of the server execution result data 122 attached to the plurality of response messages is selected and passed to the client 15 (S1
13). This selection is "randomly selected", "first come first served, 1
This is performed based on a predetermined logic such as "the first received".

Next, the RPC server processing section 12 will be described. The RPC server processing unit 12 executes the RPC of the server 16
Performs proxy processing of request reception and response return, and receives an RPC message notifying of a server group configuration change from the group configuration change notification unit 70 of the processing device 7,
Holds change information of server group configuration.

FIG. 11 is a flowchart showing the processing of the RPC server processing unit. The RPC server processing unit 12
RPC request message 11 transmitted from another processing device
When 0 is received (S301), the request content of the received message is determined (S302). This determination can be made by referring to the process identifier section 103 of the server change notification RPC message 100.

If the received message is a message notifying the change in the configuration of the server group, the group configuration change serial number section 14 in the group management table 14 of the self-processing device.
The value of 3 is incremented (S303). As a result, the RPC processing unit 10 retains information on the server group configuration change. Then, a response notifying the completion of the process of holding the information on the group configuration change is returned to the group configuration change notification unit 70 that is the RPC request source (S304).

On the other hand, in the determination in step S302,
The received request message is an RPC request message 110
In this case, the RPC server processing unit 12 executes the server (S305). That is, it acquires the arguments and the like necessary for execution of the server from the client request data section 111 of the received RPC request message 110, passes them to the server 16, and executes the procedure of the server 16. When there are a plurality of servers having the same processing identifier in the processing device, one is randomly selected and executed.

After executing the procedure of the server 16, the RPC server processing unit 12 receives the execution result from the server 16,
It is stored in the server execution result data section 122 of the RPC response message 120. The group configuration change serial number unit 12
The value of the group configuration change communication unit 143 of the group management table 14 is stored in the area 1 (S306). This RPC response message 120 is transmitted to the client that has issued the RPC request (S307). Therefore, if the change serial number in the group management table 14 has been incremented by the time of this RPC request, this change serial number is
It can be stored and transmitted in a PC response message to notify the client of the change of the server group.

The details of the RPC processing units included in the processing devices 2 to 6 have been described above with reference to the configuration of the processing device in FIG. 5 including both the client and the server. As described above, the RPC process in the system configuration of FIG. 1 can be understood by reading the processing device 2 on the client side and the processing devices 3 to 5 on the group server side.

Next, the address management unit 60 provided in the processing device 7 will be described in detail. The illustration of the RPC processing unit of the processing device 7 is omitted. The address management unit 60 manages the addresses of the servers in the system shown in FIG. 1 collectively, and stores the processing identifiers of all the servers included in the processing devices within a predetermined range (for example, within one network segment). The correspondence information with the address of the processing device is
It is stored in its own management table. Address management unit 6
0 performs addition, deletion, or reference processing of the above information in response to an RPC request message from another processing apparatus, and returns the information to the request source in a response message.

FIG. 12 is a flowchart showing the processing of the address management unit. First, when an RPC processing request is received (S401), the content of the processing request is determined (S40).
2) Process any of adding a server address, deleting a server address, or searching for a server address.

When a server is added, a request source of another processing device, for example, a certain client sends an RPC request message to the address management section 60, to which an address of a processing device having an additional server and a processing identifier of the additional server are added. Send. When determining that the request content is the addition of the server address, the address management unit 60 adds the address and the processing identifier attached to the RPC request message to the management table provided in the processing device 7 (S403), and determines whether the additional processing is successful. It is transmitted to the request source as a response message (S404).

The address management unit 60 manages servers having the same processing identifier as one server group. Therefore, in order to manage the address and the server group to which the server belongs, the address and the processing identifier are added in association with each other.

Next, when a server is deleted, a request source in another processing apparatus transmits an RPC request message with an address to be deleted and a processing identifier of the server. When the address management unit 60 determines that the request is a deletion request (S402),
The same address information as the combination of the process identifier and the address attached to the RPC request message is deleted from its own table (S405), and the success or failure of the deletion process is transmitted to the requestor as a response message (S406).

Next, when referring to the address of a processing device having a server capable of executing a certain process, a request source in another processing device sends an RPC request message with a process identifier indicating the content of the process. , To the address management unit 60. If the request is determined to refer to an address (S40)
2) Search the management table provided in the address management unit 60, and fetch the address associated with the same processing identifier as the processing identifier added to the RPC request message (S
407), and sends it to the request source with the RPC response message attached (S408).

If a plurality of addresses are obtained as a result of the search in step S407, one address may be selected at random, or all the addresses may be transmitted together with the RPC response message.

Next, the group configuration change notification unit 70 provided in the processing device 8 will be described. RPC of processing unit 8
The processing unit is not shown. The group configuration change notification unit 70 receives a request to change the configuration of a specified server group by a command input or the like from a user. For example,
A command to change the configuration of the server group 80 is issued by a command, and information such as the address of a processing device having a server to be added or deleted and the processing identifier of the server is transmitted as an argument of the command to the group configuration change notification unit 7.
0 is given.

When receiving this command, the group configuration change notifying section 70 receives the command, and
Sends an RPC request message requesting an address change. For example, an RPC request message requesting the addition of the address of the processing device having the new server is transmitted, the address is registered in the address management unit 60, and the RPC message notifying the server group configuration change is transmitted to the specified server group 80. Send to The processing devices 3 to 5 belonging to the server group 80 receive the RPC message notifying the server group configuration change,
The own address management table 13 and the group management table 14 hold server group configuration change information.

FIG. 13 is a flowchart showing a server addition process by the group configuration change notification unit. Upon receiving a request to add a server to a server group (S501), the group configuration change notification unit 70 receives an address management unit 60.
Sends an RPC request message requesting address reference of a server belonging to the server group to be added,
An address is obtained (S502). At this time, the address of any one server belonging to the group may be obtained, or the address of all servers may be obtained. In the latter case, the group configuration change notification unit 70 selects an arbitrary one.

Next, the group configuration change notifying unit 70 transmits an RPC request message requesting registration of the address of the additional server to the address management unit 60, and requests registration of the address in the management table (S503). Next, an RPC message 100 notifying the addition of the server is transmitted to the server having the address obtained in step S502 (S502).
504), a response is received from the server indicating that the processing for storing the additional information has been completed (S505).

As described above, the basic configuration and operation of the present embodiment for realizing the remote procedure call processing of the present invention have been clarified. Next, an example of processing for adding a new server to a group server for a specific remote procedure call will be described. The overall flow of this process can be broadly divided into a process of notifying a server group of the addition of a server and a process of detecting an additional server in each client-side processing device. The two processes will be described separately.

FIG. 14 is a detailed block diagram of the RPC processing unit of the system shown in FIG. 1, and the flow of processing for adding a new server is indicated by arrows. FIG. 15 is an explanatory diagram showing the specific storage contents of each of the group management tables on the client side and the server side. FIG. 16 is a flowchart illustrating the overall processing when a new server is added according to the present embodiment. The server addition processing according to the present embodiment will be described with reference to these drawings.

When the addition of the server 55 to the server group 80 is received from the user, the group configuration change notification unit 70 registers the address of the processing device 6 including the new server 55 in the address management unit 60. Further, the group configuration change notification unit 70 acquires the address of any one server in the server group 80, here, the address of the server 45, from the address management unit 60, and obtains the address R
The server addition notification RPC message 100 is transmitted to the PC server processing unit 42 as indicated by an arrow 201a (S6).
01).

Upon receiving the server addition notification RPC message, the RPC server processing unit 42 increments the group configuration change serial number of the group management table 44 in the RPC server processing unit 42 from 5 to 6, and sets the group configuration change notification unit. Then, a response message indicating the completion of the process is transmitted to 70 (S602).

Next, the process of detecting an additional server in the processing device on the client side will be described. FIG. 17 shows a flowchart of a process of detecting an additional server on the client side.

The client 15 sends an RPC request message 110 containing the processing identifier “QSORT” to the R
It is sent to the PC client processing unit 11. The RPC client processing unit 11 searches the address management table 13 and
The addresses of the processing devices 3, 4, and 5 having servers capable of executing "QSORT" belonging to the server group 80 are acquired, and RPC request messages are transmitted as indicated by arrows 205a, 205b, and 205c (S701). At this time, the change serial number corresponding to each address having “QSORT” in the group management table 14 is stored as shown in FIG.

The RPC server processing units 22, 32, and 42 of the processing devices 3, 4, and 5, which have received the RPC request message,
The server is executed in response to the RPC request as indicated by arrows 206a, b, and c (S702), and the execution result of the server is indicated by arrow 20.
7a, b, and c. The change serial numbers in the group management tables 24, 34, and 44 are indicated by arrows 208a, b, and c.
RPC that obtains the execution result and stores the change sequence number
The response message is transmitted as indicated by arrows 209a, b, and c (S703). At this time, the group management table 2
The change serial numbers of “QSORT” of 4, 34 and 44 are the contents of FIG.

The RPC client processing unit 11 receives the RPC response message from the processing devices 3, 4, and 5 (S
704), the change serial number in the RPC response message is compared with the change serial number in the group management table 14, and it is determined whether or not the configuration of the group server has been changed (S70).
5). This processing corresponds to step S of the response reception processing in FIG.
204.

Here, the RPC server processing unit 42 provided in the processing device 5 executes the server addition notification RP as described above.
The C message is received, the group configuration change serial number of “QSORT” in the group management table 44 is incremented from 5 to 6, added to the response message, and an arrow 209c is added.
Like to send. Therefore, when the RPC client processing unit 11 compares the change serial number of the RPC response message with the change serial number of the same address in its own group management table 13, the addition of a new server can be detected.

The RPC client processing unit 11 that has detected the addition of the new server acquires the address information of all the servers from the address management unit 60, compares it with the address information of its own address management table 13, and obtains the server information obtained as a difference. The 55 address information is added to the address management table 13 and the group management table 14 (S70).
6). Next, the RPC client processing unit 11 selects one of the RPC response messages received from each of the processing devices 3, 4, and 5 and passes it to the client 15 as a server execution result (S707).

In the above description, the group configuration change notification unit 7
0 is provided by the processing device 8,
Any processing device may be provided. For example, the processing device 6 may include the group configuration change notification unit 70. At this time, the server 55 may notify the group configuration change notification unit 70 of its own addition request, and request the group configuration change notification unit 70 for an addition processing request.

If the determination in step S302 in FIG. 11 is a server addition request, it is determined whether or not a new server can be added to the designated server group, and then the process proceeds to step S30.
3 may perform additional processing.

For example, in the server group 80 of FIG. 1, there are servers that cannot be multiplexed in the group 80,
It is assumed that the processing identifier is “CSORT”. In this case, if the server 55 is added, the server of “CSORT” is multiplexed. Accordingly, upon receiving the processing identifier of the additional server in the RPC notification message 100, the RPC server processing unit 42 checks the processing identifier in the group management table 14, and suspends the additional processing when the "CSORT" server is multiplexed. I do. Alternatively, when the server group has a completely multiplexed configuration, it is determined whether the processing identifiers of the servers to be added are the same by comparing them with the processing identifiers of the group management table 14, and if not, a response indicating that addition is impossible is returned. .

In addition, user IDs, program IDs, and authentication information for which additional processing is permitted are stored in advance in the RPC server processing section, and the requesting user ID, program ID, or authentication information is added to the RPC notification message. Then, the information may be compared at the time of reception to determine whether or not additional information is necessary.

As described above, according to the configuration of the present embodiment, the client-side computers that call a plurality of servers in parallel in response to one request by using the RPC are independently and asynchronously connected to the plurality of servers. It detects a change in the configuration of the group formed by the remote procedure and performs a group configuration change process. Information for this detection is added to the normal RPC response and transmitted to the client side. Therefore, when the group configuration is changed, the additional processing message accompanying the change is not concentrated on the network, and the load on the network, the computer on the remote procedure side added with the configuration change or the name server for managing the address of the remote procedure, etc. Can be distributed over time.
In particular, it is not necessary for the client computer to constantly monitor the presence or absence of a change in the group configuration, and the change can be detected from the content of the response to the own RPC request. .

Further, according to the present embodiment, when the remote procedure constitutes a multiplexing server and the client accesses the multiplexing server, the client computer accessing each server before and after adding the server is the same. Since the group configuration can be changed, the consistency of the internal state of the server is guaranteed, and this is useful as a communication system for a multiplex server. Further, the multiplicity of the server can be changed to online.

In this embodiment, the client issues an RPC request to all servers in the group.
However, the RPC may be issued to some servers in the group. According to this, when the client detects the additional server, the additional server can be used in place of the request destination server that has issued the RPC up to that time, and the processing load can be distributed within the server group. Alternatively, the server can be upgraded online using a new version of the additional server in place of the old version of the request destination.

The server may not be provided in the form of a procedure. The program may execute its own processing in response to the request and return the execution result to the request source.
That is, the timing of returning the execution result to the request source does not necessarily need to be at the end of the execution of the own process, and may be a program that returns some data to the request source during the execution of the own process. Further, the program executed by the server in response to the processing request does not necessarily need to output the processing result. At the end of processing or at the start of processing, the RPC processing unit on the server side may return an RPC response message without storing any data in the execution result data part.

Further, in this embodiment, the group configuration of the multiplexing server is shown in FIG. 1 assuming that the same processing identifier represents the same processing content. However, the present invention is not limited to this. In RPC, even if a server has a different name or a procedure that performs a process, the server can have the same process identifier regardless of the procedure name and the process content held by the server. When such an identifier is assigned, the transmitting side can send a transmission message without being aware of the contents of the procedure held by each server in the group, so that there is an advantage that the load on the transmitting side can be reduced. .

[Second Embodiment] In the present embodiment, unlike the first embodiment, the server detects the presence or absence of a change in the group configuration. That is, the client sends an RPC to the server.
Is issued, the change serial number held by the client is stored and transmitted in the RPC request message, and the server compares the change serial number with the change serial number stored in the group management table of its own processing device. Then, the presence or absence of a change in the group configuration is detected. The following description focuses on the differences from the first embodiment. Note that the system configuration is the same as that of the first embodiment, and the configuration of FIG. 14 will be referred to below.

FIG. 18 shows the format of an RPC request message sent by the processing device on the client side. In the RPC request message (FIG. 3) in the first embodiment,
A group configuration change serial number unit 112 for storing the change serial number held by the client is added.

FIG. 19 shows the format of an RPC response message in which the processing device on the server side returns an execution result to the client side. The RPC response message (FIG. 4) of the first embodiment is added with a change flag unit 123 for notifying the presence or absence of a configuration change in a server group.

The processing performed by the RPC client processing section 11 will be described. First, in step S106 of the processing flow (FIG. 8) according to the first embodiment, when the RPC client processing unit 11 issues an RPC request message to the server, the change serial number corresponding to the address of the request destination server is set in the group management table. 14 and removed from FIG.
As shown in (b), the RPC request message is stored in the group configuration change serial number unit 112.

FIG. 20 is a flowchart of the response receiving process of the RPC client processing unit according to this embodiment. R
Upon receiving the RPC response message 120 from the server (S801), the PC client processing unit 11 checks the change flag unit 123 and determines whether or not there has been any addition to the server group (S802). Additional flag is set (O
N) If yes, it is determined that the server group 80 has been changed, and the processing of S803 to S807 is performed. here,
The processing of steps S803 to S807 is the same as the processing of steps S205 to S209 shown in FIG. 10 of the first embodiment.

Next, the processing performed by the RPC server processing section on the server side will be described. FIG. 21 is a flowchart of the response receiving process of the RPC server processing unit according to the present embodiment, which is executed by, for example, the RPC server processing unit 42 of the processing device 5. In the figure, steps S901-S904
Are S201 to S20 in the first embodiment (FIG. 11).
The processing is the same as the processing in FIG.

If it is determined in step S902 that the request message is not a server change, the server requested by the client is first executed (S905). Upon receiving the execution result from the server, the RPC request message 120
Is acquired (S906), and is compared with the change serial number managed in the group management table 44 of the own processing device 5 (S907). As a result of the comparison, if the own change serial number is higher, the RPC is performed as shown in FIG.
The server addition flag of the response message is turned ON (S91
0), the own change serial number is added to the RPC response message 120 (S911), and returned to the processing device 2 on the client side together with the execution result of the server (S912).

On the other hand, if the acquired change serial number is equal to or less than the own change serial number, the server addition flag of the RPC response message is turned off (S909), and the RPC response message 1
20 is added to its own change serial number (S911), and returned to the requesting processing device together with the execution result of the server.

Thereafter, the RPC client processing unit 11
Is the ON / OFF of the additional flag of the response message 120
Is determined, and the group management table 14 and the address management table 13 are updated in steps S803 to S807.

Although the example of server addition has been described above, in the case of server deletion, a server deletion flag is prepared and its ON / OFF is determined. Alternatively, a change flag that is shared for addition and deletion of servers is prepared, and if the acquired group configuration change serial number is different from the own change serial number as a result of the comparison in step S907, it is determined that there is a change in the group configuration. Then, steps S803 to S807
May be performed.

According to this embodiment, since the server determines whether or not there is a change in the server group configuration, the processing of the client can be reduced. In particular, in the case where unauthorized server change requests continue, it is possible to avoid overloading the client.

[Third Embodiment] Next, a third embodiment will be described. In the first and second embodiments, when a client processing device calls a server in a server group,
The multicast method of transmitting an RPC request message directly to a plurality of servers has been used. On the other hand, in the present embodiment, the processing device of the client transmits an RPC request message to an arbitrary server in the server group, executes the server to which the processing device that has received this message is the destination, and executes the remaining server in the group. The RPC request message is transferred to all the servers, and each processing device that has received the transfer message executes its own server.

FIG. 22 is a system configuration diagram for explaining the addition of a server according to the present embodiment. The details are the same as in FIG. FIG. 23 shows a format of an RPC request message and a response message according to the present embodiment. In the RPC request message of FIG. 3A, a transfer message flag unit 113 is added to the RPC request message of FIG. In the response message shown in FIG. 9B, the change flag section 123 is provided, and the group configuration change serial number section 121 is deleted.

Next, processing for adding a server in this embodiment will be described. The overall flow of this process can be divided into a process of notifying a server group of the addition of a server and a process of detecting an additional server in each client-side processing device. Since the former process is the same as that of the first embodiment, only the latter process will be described below.

The RPC client processing section 11 is an arbitrary one set in advance as a master server in the group.
Here, an RPC request message is transmitted to the server 25 of the processing device 3 here. Note that the group management table 24 of the master processing device 3 manages its addresses and change serial numbers so that all servers in the group 80 can be called.

Upon receiving the RPC request message from the client, the RPC server processing unit 22 of the processing device 3
Since the transfer message flag is OFF,
If it is determined that the message is not a transfer message, a transfer RPC request message is transmitted to all the other servers in the group, and the transmitted transfer RPC request message is received by the processing devices 4 and 5, respectively.

The RPC server processing units 32 and 42 in the processing devices 4 and 5 that have received the RPC request message execute the server in response to the RPC request, acquire the execution result of the server, and The RPC response message in which the changed serial numbers in 34 and 44 are acquired and the stored serial numbers are stored is transmitted to the RPC server processing unit 22 which has transmitted the transfer RPC request message.

When the RPC server processing unit 22 has received the group configuration change notification, the RPC server processing unit 22
To update. Further, the change serial numbers in the RPC response messages from the processing devices 4 and 5 are compared with the change serial numbers in the group management table 24 to determine whether there is a change in the group configuration. If there is a change, the group management table 24 is updated.

The RPC server processing section 20 sends the processing result of its own server 25 to the client and the other destination server 3
When the group management table 24 has been updated first when transmitting the execution results from 5, 45, the change flag unit 1
The change flag is set (ON) in 23.

The RPC client processing unit 11 that has received the RPC response message from the processing device 3 determines that there is a change in the configuration of the server group 80 if the change flag of the message is ON. Of the address management table 1
Compare with address 3 As a result, the address of the server 55 that becomes the difference is added to the address management table 13 and the group management table 14. Next, the RPC client processing unit 11 selects one from the server execution results of the processing devices 3, 4, and 5 in the RPC response message, and passes it to the client 15. In this embodiment, the client does not need a group management table.

According to this embodiment, the RP is added to the server group.
When the C request is made, transmission and reception are performed only with the processing device arbitrarily selected in the group, and the RPC request message is transferred to all the remaining servers of the other processing devices in the group for processing. Since the indirect multicast method is used, it is possible to reduce the processing load on the client and the network.

[Fourth Embodiment] Next, a fourth embodiment will be described. In the first, second, and third embodiments, RPC is used as a communication method between the client and the server. R
In a distributed processing system in which a plurality of information processing apparatuses are connected to each other via a network, a PC is configured such that a client in one processing apparatus can use another PC in the same manner as a procedure call in its own processing apparatus. This is a request-response communication method in which a procedure provided by a server existing in the server is called and a processing procedure for receiving the execution result is performed. However, RPC internally
(1) communication of a request message from the client to the server, (2) communication of a response message from the server to the client, and (3) an executable program on the server side is provided in the form of a procedure. (4) A request response characterized in that processing is performed so that a client can call a procedure provided by a server existing in another processing device by the same method as a procedure call existing in its own processing device. One form of communication.

The gist of the present invention is that the communication method between the client and the server is not limited to the RPC, but the communication method between the client and the server is replaced with at least the remote procedure call request / response.
Any request-response communication combining (1) communication of an execution request message from a client to a server and (2) communication of a response message from a server to a client is applicable.

In any of the first, second, and third embodiments, a request message may be used instead of the remote procedure call request, and a response message may be used instead of the remote procedure call response. In this case, the first, second,
The system configuration and the configuration in the processing device in each of the third embodiments are the same as in the fourth embodiment, and the processing contents may be the same. As for the format of the RPC message, it is only necessary to change the RPC control header section to a request / response communication control header section including control information for request / response communication.

As described above, the gist of the present invention is not limited to the communication method between the client and the server in particular to the RPC, but is applicable if the communication method between the client and the server is the request response communication. The same effect as in the case can be obtained.

[0120]

According to the present invention, the client computer can detect a change in the configuration of the server group during operation. Therefore, the system administrator can add a server to a server group while operating the application system, add a new service, increase the multiplicity, upgrade the server, and so on. Performance, maintainability, and fault tolerance can be improved. In addition, while operating the application system, the server can be deleted from the server group and unnecessary servers can be separated, thereby improving the system scalability and maintainability.

Further, the detection information of the change in the group composition is as follows.
Since transmission / reception is performed in addition to the RPC response or the request response, the load on the network due to the change does not occur.
Further, it is not necessary for the client computer to constantly monitor whether there is a change in the group configuration, and the client computer can detect the change from its own RPC request or the response to the request communication. There is no increase.

Further, according to the present invention, when the multiplex server is configured on the remote procedure side, the client computer accessing each server before and after server addition can be made the same, and the internal state of the server can be changed. Since the consistency is guaranteed, it is useful as a communication system of the multiplex server.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a system configuration to which a remote procedure call processing method according to the present invention is applied.

FIG. 2 is a format diagram of a server change notification RPC message according to one embodiment;

FIG. 3 is a format diagram of an RPC request message according to one embodiment.

FIG. 4 is a format diagram of an RPC response message according to one embodiment.

FIG. 5 is a configuration diagram of a processing device provided with a client and a server.

FIG. 6 is a format diagram showing contents of an address management table.

FIG. 7 is a format diagram showing contents of a group management table.

FIG. 8 is a flowchart illustrating an overall processing operation of the RPC client processing unit according to the first embodiment.

FIG. 9 is a flowchart illustrating details of a table initialization process.

FIG. 10 is a flowchart illustrating a response receiving process of the RPC client processing unit.

FIG. 11 is a flowchart illustrating a processing operation of an RPC server processing unit according to the first embodiment.

FIG. 12 is a flowchart illustrating a processing operation of an address management unit.

FIG. 13 is a flowchart illustrating a processing operation of a group configuration change notification unit.

FIG. 14 is a system configuration diagram illustrating the flow of a server addition process.

FIG. 15 is an explanatory diagram showing specific management contents of each group management table in the system configuration of FIG. 14;

FIG. 16 is a flowchart illustrating the flow of a server addition process on the server side.

FIG. 17 is a flowchart showing a server addition detection process on the client side.

FIG. 18 is a format diagram showing an RPC request message in the second embodiment.

FIG. 19 is a format diagram showing an RPC response message in the second embodiment.

FIG. 20 is a flowchart illustrating a processing operation of a response receiving process of the RPC client processing unit according to the second embodiment.

FIG. 21 is a flowchart illustrating a processing operation of an RPC server processing unit according to the second embodiment.

FIG. 22 is a system configuration diagram illustrating a flow of processing of an indirect multicast method in a third embodiment.

FIG. 23 is a format diagram showing an RPC request message and a response message in the third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Communication medium (network), 2-8 ... Processing apparatus (computer), 10, 20, 30, 43, 50 ... RPC processing part, 11 ... RPC client processing part, 12, 22, 3
2, 42, 52 ... RPC server processing unit, 13 ... address management table, 14, 24, 34, 44, 54 ... group management table, 143 ... group configuration change serial number unit, 2
5,35,45,55,401,402,403,41
1,412,413,421,422,423,43
1,432,433 ... server, 60 ... address management unit,
70: group configuration change notification unit, 80: server group, 100: server change notification RPC message, 101
... RPC control header section, 102 ... RPC request content identifier section, 103 ... changed server processing identifier section, 110 ... RPC
Request message, 111 ... client request data part,
120: RPC response message, 121: Group configuration change notification unit, 122: Server execution result data unit

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Noriyoshi Ando 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Inside Hitachi, Ltd.System Development Laboratory (72) Inventor Shigeki Hirasawa 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Stock Company (72) Inventor Hiroshi Wataya 5-2-1 Omikacho, Hitachi City, Ibaraki Prefecture Inside Omika Plant, Hitachi Ltd. (72) Kenji Matsuzaki 5-chome, Omikamachi, Hitachi City, Ibaraki Prefecture No. 1 Hitachi Process Computer Engineering Co., Ltd. (72) Inventor Seiichi Tamura 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi Process Computer Engineering Co., Ltd. (72) Inventor Jun Suzuki Hitachi, Ibaraki 5-2-1, Omikacho Computer Engineering Co., Ltd. in

Claims (5)

[Claims] 1. A remote procedure call processing method for calling a plurality of grouped servers in response to a request of one remote procedure call, wherein, when changing the configuration of the server group, change information of a change server to be added or deleted Is held by any server belonging to the server group, and when this server returns an execution result corresponding to an execution request issued from a request source of each remote procedure call to the request source, A remote procedure call processing method characterized by adding change information. 2. A remote procedure call processing method for calling a plurality of grouped servers in response to a request for one remote procedure call, wherein any one of the server groups is notified of a change in group configuration. The server receiving the notification holds the change information of the change server to be added or deleted, and when a procedure execution request is issued from the request source of the remote procedure call to a plurality of grouped servers, the server holding the change information becomes Upon receiving one of the execution requests and returning the execution result of the corresponding procedure as a response message to the request source, the change information is added, and the request source determines a member of a server group to be called by itself based on the change information. A remote procedure call processing method, characterized in that: 3. A remote procedure call processing method for calling a plurality of grouped servers in response to a request for one remote procedure call, wherein any one of the server groups is notified of a change in group configuration. The server receiving the notification increments the change information held by the server, while the remote procedure call request source transmits the current execution information stored for each server to be called to the execution request of the procedure transmitted to each grouped server. When each of the servers receives one of the execution requests,
The corresponding procedure is executed, and the change information added to the execution request is compared with the change information held by the own. If the change information does not match, the change message is returned to the request source together with the change result in the response message. And a request source that has received the response message changes a member of a server group to be called when the change flag is set. 4. Calling a plurality of grouped servers in response to a request of one remote procedure call, representing one server arbitrarily selected by a remote procedure call request source from members of the server group. And the called representative server executes its own processing, duplicates the content requested by the requesting source, and calls the remaining member servers. One of the servers is notified of the change in the group configuration, and the server holding the change information of the change server that receives the notification and adds or deletes the change request is issued a procedure execution request from the request source to the representative server, When the contents of the duplication request are transferred from the representative server, the And returns a response message to the representative server obtained by adding the change information on the execution result that,
The remote procedure call processing method, wherein the representative server changes a member of a server group to be called by the representative server based on the change information. 5. The method according to claim 1, wherein, as the change in the group configuration, a new server is added to the server group, and each request source of the remote procedure call that has detected the addition of the new server is changed. A remote processing unit that selects whether a server that has been a processing request destination up to this time or the new server is a new processing request destination, and distributes processing performed by the procedure execution side among servers in the group. Procedure call processing method.