JPH0831072B2 - Message attribute detection processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A message attribute detection processing method in a data processing system in which a reception server that accepts a service request from a client requests a processing server to provide a service to the client. The reception server manages the retransmission count value of the message to be sent to the processing server, and the retransmission count management unit that manages the retransmission count value of the message to be transmitted to the processing server for the purpose of efficiently detecting the received retransmission / redundant message. A retransmission count value managed by the retransmission count value management unit, and a retransmission count value addition unit that adds the identifier and the retransmission count value of the message notified from the client process that issued the message to the message. Prepare,
The processing server retains the identifier and the two types of retransmission count values attached to the message sent from the reception server as the transfer information to the standby system, and the message sent from the reception server. Attached 2
It is configured to include a message attribute detection unit that detects whether the message is a retransmission or a redundant transmission by comparing the value of the number of retransmissions of each type with the corresponding holding value held by the inheritance information management unit. .

[Industrial applications]

The present invention relates to a message attribute detection processing method in a data processing system in which a reception server that receives a service request from a client process requests a processing server that is a service provider to provide a service to a client process. In particular, the present invention relates to a message attribute detection processing method that enables a processing server to efficiently detect whether a sent message is a resent message or a redundant message.

[Conventional technology]

When a configuration is adopted in which message communication is performed between application programs and data processing is executed, when there is no response to the sent message, it is determined that the application program to which the message is sent is down. Therefore, in the related art, when the data processing is executed based on the message communication, the configuration is such that the processing ends abnormally when there is no response to the transmitted message.

However, if the destination of the message is a global service program that runs in a unique space in the system and locks the system resources in the space to control the resources of the entire system, the service provision is suspended. To prevent this from happening, we have an active system and a standby system, and when the active system goes down, the process is taken over by the standby system so that FT (fault tolerant)
The configuration will be adopted. From this, it is considered that the source of a message does not go down when the destination of the message is a global service program, even if there is no response to the transmitted message. It is conceivable to adopt a configuration in which the message is retransmitted.

That is, as shown in FIG. 7, a client process 1, a first server 2 that receives a service providing request from the client process 1, and a second server that receives a service providing request from the first server 2. In the case where the first server 2 and the second server 3 are configured as a global service program in the case of performing data processing according to message communication, the first server as a message destination. When 2 crashes, as shown in FIG. 8, the client process 1 retransmits the message to the first server 2 of the new active system that has taken over the process, and at the same time, the first process as the message sender. When the server 2 crashes, as shown in FIG. 9, the first server of the new active system that has taken over the processing. There is to process to continue to resend the message to the second server 3. Here, FSS in the figure is a non-volatile special storage area for writing information required for the active system to take over the processing to the standby system.

[Problems to be Solved by the Invention]

What should be considered when adopting such a data processing configuration is to know whether the message sent is a message relating to a new request, a resend message, or a redundant message. The point is that it is necessary. If it is a message related to a new request, the process of the request must be executed, and if it is a resend message, it must be judged whether or not it has been processed, and if it has not been processed, the process must be executed. This is because if it is a junk message, it has already been processed, so it is necessary to do nothing.
From now on, in order to realize FT by retransmitting the message, it is necessary to equip the receiving side with means for detecting the retransmitted / redundant message.

On the other hand, when the first server 2 executes a process that leaves resources, the first server 2 needs to record the received request information in the FSS in preparation for a crash. If all the requests sent from the client process 1 are treated as new requests when the processing that does not leave the request is executed, it is not necessary to record the received request information in the FSS. Is mentioned.

From this, it is not necessary to directly apply the resending / redundant message detection algorithm applied to the resource-retaining one to the one that executes the processing in which the first server 2 does not leave the resource, On the other hand, if you apply it as it is, you will have to prepare an unnecessary FSS memory area.

The present invention has been made in view of such background,
A reception server that receives a service request from a client process and a plurality of processing servers that provide services to the client process are provided, and the reception server identifies the processing server that provides the service and provides the service to the client process. In a data processing system that adopts a requesting configuration, the processing server sends a
An object of the present invention is to provide a new message attribute detection processing method that enables efficient detection of redundant messages.

[Means for solving the problem]

 FIG. 1 is a block diagram showing the principle of the present invention.

In the figure, 10 is a client process, which executes predetermined data processing while receiving service provision,
Reference numeral 20 denotes a reception server that receives a service request from the client process 10. Reference numeral 30 denotes a plurality of processing servers that provide a prescribed service to the client process 10.

The client process 10 includes a data processing unit 11, a message transmission unit 12, and a retransmission count value management unit 13. The data processing unit 11 issues a request for providing a service required to execute data processing. The message sending unit 12
A service request message is transmitted to the reception server 20 in response to a service request issued from the data processing unit 11. The message transmitted at this time is added with an identifier for identifying the message and a resend count value a indicating the resend count of the message. The retransmission count value management unit 13 manages the retransmission count value a of this message in association with the message identifier.

The reception server 20 includes a message reception unit 21, a processing server identification unit 22, a message transmission unit 23, and a retransmission count value management unit.
24 and a retransmission number value adding unit 25. The message receiving unit 21 receives the service request message sent from the client process 10. Processing server identification unit
22 identifies the processing server 30 that is the provider of the service specified by the received service request message. The message transmission unit 23 transmits the service request message regarding the received service request message to the specified processing server 30. The message sent at this time is
The identifier attached to the message sent from the client process 10 and the resend count value a are added, and the resend count value b indicating the resend count of the send message from the reception server 20 is added. Will be.

The retransmission count value management unit 24 manages the retransmission count value b in association with the message identifier. Retransmission count value addition unit 25
Is expanded in the message transmission unit 23, and for the message transmitted by the message transmission unit 23, the retransmission count value managed by the retransmission count value management unit 24 and the client process 10 that has issued the message. The identifier of the notified message and the value of the number of retransmissions are added. That is, in the case of the above-mentioned example, for the service request message transmitted to the processing server 30, the retransmission count value b managed by the retransmission count value management unit 24 and the service request message are the issue source. The identifier attached to the message sent from the client process 10 and the retransmission count value a are added.

In this way, the reception server 20 is a client process.
It executes the process of identifying the processing server 30 that is the source of the service required by the server 10, and does not execute the process of leaving resources such as writing information to the disk. From now on, the reception server 20 of the present invention treats the service request message sent from the client process 10 as a new one regardless of whether it is retransmitted or redundantly transmitted, thereby omitting the recording of the takeover information in the FSS. Is taken.

The processing server 30 includes a message receiving unit 31, a takeover information managing unit 32, a message attribute detecting unit 33, and a service providing unit.
34 and. This message receiving unit 31 is a reception server
Receive the service request message sent from 20. The takeover information management unit 32 holds information such as the identifier attached to the received message and the two types of retransmission count values a and b in a nonvolatile manner as takeover information to the standby system. The message attribute detection unit 33 compares the identifier attached to the received message with the identifier held by the inheritance information management unit 32, which is expanded in the volatile memory, so that the received message is a new service. It detects whether it is a request or not, and if it is not new, two types of retransmission count values a and b attached to the received message and the takeover that is expanded in the volatile memory. By comparing with the corresponding holding value held by the information management unit 32, it is detected whether the received message is a resend message or a redundant message. The service providing unit 34 executes a service providing process for the client process 10 according to the detection result of the message attribute detecting unit 33.

[Action]

In the present invention, the message attribute detection unit 33 of the processing server 30
First, it judges whether or not the identifier attached to the received message is held in the takeover information management unit 32. When it is detected by this judgment processing that the message is not held, it is judged that the received message is related to a new service request. On the other hand, when it is detected that the message is held, it is then determined whether the retransmission count value a attached to the received message is larger or smaller than the corresponding held value held in the takeover information management unit 32. to decide.

When the message attribute detection unit 33 detects that the retransmission count value a attached to the received message is larger than the corresponding held value by this determination processing, the received message is a retransmission message. Judge and, conversely,
When it is detected that it is small, it is determined that the received message is a redundant message. On the other hand, if it is detected that they are equal, then it is determined whether the retransmission count value b attached to the received message is greater than, equal to, or less than the corresponding retention value retained in the takeover information management unit 32. To do.

When the message attribute detection unit 33 detects that the retransmission count value b attached to the received message is larger than the corresponding held value by this determination processing, the received message is a retransmission message. If it is determined that they are equal or smaller, it is determined that the received message is a redundant message.

As described above, in the present invention, in view of the characteristic that the reception server 20 does not execute the process of leaving resources, all the service request messages sent from the client process 10 to the reception server 20 are novel. The reception server 20 does not judge whether the message is retransmitted or redundantly transmitted, and has a configuration in which the recording of the takeover information in the FSS is omitted. Then, the processing server 30
Since it is configured to judge whether the received message is a resend message or a redundant message according to the two kinds of resend count values a and b attached to the sent message, the memory capacity is reduced. At the same time, it becomes possible to efficiently detect a retransmission / redundant message with a small number of dynamic steps.

〔Example〕

 Hereinafter, the present invention will be described in detail according to examples.

FIG. 2 illustrates a system configuration of a data processing system to which the present invention is applied. In the figure, 10 is the client process described in FIG. Reference numeral 20a is a file name management server that manages the correspondence relationship between the names of all files in the system and the volumes in which those files exist, and 30a is a file resource management server that is provided for each volume. A file resource management process such as a process of issuing a usage right of a file in a volume is executed. Here, the file name management server 20a
Also, the file resource management server 30a is provided with a standby system in addition to the active system in case of a crash. Although not shown in the figure, the file resource management server
30a is a special storage area for writing information necessary for taking over the processing to the standby system, which is the FS described above.
It has S.

As shown in this figure, the client process 10 transmits a file use right acquisition request message to the file name management server 20a, and when this message is received, the file name management server 20a determines that the file for which the acquisition request has been made. The existing volume is specified, and a file use right issue request message is transmitted to the file resource management server 30a that manages the file use right for the specified volume. Then, upon receiving this message, the file resource management server 30a executes exclusive acquisition of the file, issues the acquired file usage right capability (cap in the figure) to the file name management server 20a, and The management server 20a transfers the file usage right capability to the client process 10. In this way, when the file usage right is acquired, the client process 10 directly requests the file resource management server 30a to open the exclusively acquired file resource (α in the figure) pointed to by the transferred capability. And the reference number of the attribute information will be requested.

In this process, when the file name management server 20a crashes, the client process 10 retransmits the file use right acquisition request message in consideration of the fact that the process is taken over by the standby system. When the file resource management server 30a crashes, the file name management server 20a resends the file usage right issue request message in consideration of the fact that the processing is taken over by the standby system. It will be processed as it goes. From now on, the file resource management server 30a
Needs to have a means for detecting the retransmitted message and a means for detecting a processed redundant transmission message which is delayed for some reason.

Next, the retransmission / redundant message detection processing according to the present invention will be described in detail with reference to the flowcharts shown in FIGS. Here, the flowchart of FIG. 3 is a flowchart executed by the client process 10, the flowchart of FIG. 4 is a flowchart executed by the file name management server 20a, and the flowchart of FIG. 5 is a file resource management server. It is a flowchart which 30a performs.

The client process 10 uses the file name management server 20a as shown in step 10 of the flowchart of FIG.
A file use right acquisition request message. At this time, the client process 10 adds a unique message ID to the message to be transmitted, and also adds the retransmission count value of the message (retransmission count a explained in FIG. 1). Then, in step 11,
In response to a message server (not shown), it is detected that the message does not reach the message transmission process, or the file name management server 20a at the transmission destination is detected to have crashed. In the following step 12, while incrementing the count value of the counter that manages the number of retransmissions, the process returns to step 10, the incremented number of retransmissions is added, and the file name management server 20a is again notified of the file usage right. Processing will be performed so as to transmit the acquisition request message.

In this way, as shown in FIG. 6, the message sent from the client process 10 to the file name management server 20a is added with the message ID and the retransmission count value a.

File name management server 20a is the client process 1
When the file use right acquisition request message is received from 0, as shown in the flowchart of FIG. 4, the retransmission / redundant detection processing is not performed on the received message,
Immediately go to step 21 and select client process 10
Specifies the volume in which the file specified by the file exists, and then in step 22, the file resource management server 30 that manages the file usage right for the specified volume.
Send a file usage right issue request message to a. At this time, the file name management server 20a responds to the message sent by the client process 10
The message ID and the number of times of retransmission a sent from are added, and the number of times of retransmission of the message to be transmitted (the number of times of retransmission b described in FIG. 1) is added.

Then, in step 23, it is detected that a message does not reach the message transmission processing or a file resource management server 30a of the transmission destination has crashed according to a message server (not shown) in step 23. Then, in the subsequent step 24, the file name management server 20a increments the count value of the counter that manages the number of retransmissions (the number of retransmissions b is incremented), and returns to step 22 to set the incremented number of retransmissions. Add the file resource management server again
Processing is performed so as to send a file usage right issuance request message to 30a. On the other hand, if it is confirmed in step 23 that the message has arrived, the process proceeds to step 25, and message reply processing is executed to the client process 10.

Thus, as shown in FIG. 6, the message sent from the file name management server 20a to the file resource management server 30a includes the message ID and the resend count value a sent from the client process 10. The number of times of retransmission b, which is the number of times of retransmission of the message from the file name management server 20a, is added.

When the file resource management server 30a receives the file usage right issuance request message from the file name management server 20a, as shown in step 31 of the flowchart of FIG. Determine if it is registered. This judgment processing is expanded in the volatile memory as shown in FIG.
It will be executed by searching the retained information of FSS. Message ID sent according to this judgment process
When it is determined that the file use right with the file has not been registered yet, the process proceeds to step 32, the process is performed as a new request, and in the following step 33, the exclusion of the file is acquired and the resource is created, and in step 34. , Secure the area for writing the restoration information in the FSS, then in step 35,
The message ID sent to the secured FSS area,
The number of retransmissions “a” and the number of retransmissions “b” are written out, and other information necessary for restoration is written out. When the file use right is acquired in this way, the file resource management server 30a processes the capability to provide the capability to the client process 10 via the file name management server 20a, as shown in FIG. Become.

On the other hand, according to the judgment processing of step 31, when it is judged that the file use right having the sent message ID is already registered, the process proceeds to step 36, and the sent retransmit count a becomes the file use right. It is judged whether or not the number of times of retransmission is larger than the set number of times of retransmission a, and when it is judged to be large, it is judged that the received message is retransmitted. On the other hand, when it is determined in step 36 that it is not large, the process proceeds to step 37, and it is determined whether or not the number of retransmissions a sent this time is smaller than the number of retransmissions a set in the file usage right. Then, when it is judged that it is small, it is judged that the received message is a redundant message.
On the other hand, if it is determined in step 37 that the sent retransmit count a is equal to the retransmit count a set in the file usage right, the process proceeds to step 38 and the sent resend It is determined whether or not the number of times b is greater than the number of times of retransmission b set in the file usage right, and when it is determined to be greater, it is determined that the received message is a retransmission, and when it is other than that, that is, when it is equal to or less than that. The received message is judged to be a joke.

When the file resource management server 30a determines that the message is a redundant message, the file resource management server 30a finishes the process without executing any process because it has already been processed. on the other hand,
If it is determined that the message is a resend message, step 39
In step S40, the number of retransmissions a and b held in the FSS is rewritten and updated, and in step S40, the process corresponding to the retransmission message is executed. That is, it is confirmed that the same process is performed, the process is terminated if the same process is confirmed, and the same process is not performed. If so, the process is continued.

Thus, in the present invention, the file name management server
Since it is configured so that the determination of resending / redundant transmission is not required in 20a, the file use right can be provided to the client process 10 at high speed.

[Effects of the Invention] As described above, in the data processing system in which the client process calls the reception server and the reception server calls the processing server by using the present invention, the reception server is a resource. In case of not leaving, the message resending / redundant detection process suitable for it can be realized.
While reducing the memory capacity, it becomes possible to efficiently detect the retransmitted / redundant message with a small number of dynamic steps.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a block diagram of a data processing system to which the present invention is applied, FIG. 3 is a flowchart executed by a client process, and FIG. 4 is executed by a file name management server. 5, FIG. 5 is a flowchart executed by the file resource management server, FIG. 6 is an explanatory view of processing of the present invention, and FIGS. 7, 8 and 9 are explanations of a data processing system of a client / server model. It is a figure. In the figure, 10 is a client process, 20 is a reception server, 20
Reference numeral a is a file name management server, 30 is a processing server, and 30a is a file resource management server.

Claims (2)

[Claims] 1. A reception server (20) for receiving a service request from a client process (10), and a plurality of processing servers (30) for providing services to the client process (10), the reception server (20) comprising: A data processing system that identifies a processing server (30) that is a provider of a received service request and requests the processing server (30) to provide a service to a client process (10) In, the reception server (20) manages the retransmission count value of the message transmitted to the processing server (30), and the retransmission count management unit (24)
And for the message to be sent to the processing server (30),
The retransmission count value managed by the retransmission count value management unit (24) and the client process (1
(0) is provided with a message identifier and a retransmission count value adding unit (25) that adds a retransmission count value, and the processing server (30) is attached to the message sent from the reception server (20). Existing information and two types of resend count values as takeover information to the standby system, and two types of resend count values attached to the message sent from the reception server (20) And a message attribute detection unit (33) for detecting whether the message is a resend or a redundant transmission by comparing the corresponding hold value held by the takeover information management unit (32). Is a message attribute detection processing method characterized by. 2. The message attribute detection processing method according to claim 1, wherein the message attribute detection unit (33) holds a value of the number of retransmissions from the client process (10) attached to the transmitted message as a corresponding value. When it is larger than the value, it is judged as a resend message, when it is smaller, it is judged as a redundant message, and when the values are the same, and the number of times of resending from the reception server (20) attached to the message corresponds. A message attribute detection processing method characterized in that if it is larger than the held value, it is judged as a retransmitted message, and if it is smaller or equal, it is judged as a redundant message.