JPH07200435A - Message communication system of decentralized processing system - Google Patents

Abstract

PURPOSE:To improve the performance of the decentralized processing system by taking a process request in a process executable node and executing the request. CONSTITUTION:On the side of a processing request node 110, a function address adding means 114 adds a function address to a request message and sends them to a transmission line 100. On the side of the processing execution node 120, an address changing means 125 takes in the request message only when the function address of the received request message matches its function address, changes the transmission destination address into its node address, and passes it to AP 121, and a function address adding means 124 sends an answer message back to the transmission line 100. On the side of the processing request node 110, an address changing means 115 changes the transmission source address in the received answer message into the request destination address and a selecting means 116 selects and passes an adequate answer message to AP 111.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system of request messages for requesting processing between nodes and corresponding response messages in a distributed processing system in which a plurality of nodes (computers) are connected via a transmission line. .

[0002]

2. Description of the Related Art Conventionally, in a distributed system in which a plurality of nodes are connected via a transmission line, there are mainly the following two message communication systems between nodes.

The first method is a global / group communication method. In this method, when sending a request message for a processing request, the processing request node specifies a global address for all nodes or a group address for a part of the node group as a destination address, and sends it. As the original address, a node address fixed to the request node is designated, and processing request information in which a function code corresponding to the desired processing type is set, predetermined control information, and the like are added and transmitted to the transmission path. When each node connected to the transmission path receives the request message, it determines whether the global / group addresses match, and if they do not match, the request message is received by the application program after the communication control processing of capturing without matching Execution is determined based on the function code inside, and if there is no application program corresponding to the function code, it is ignored, and if there is a corresponding application program, it is executed. Then, the processing execution node returns a response message including a destination address designated by the node address unique to the requesting node, a transmission source address designated by the node address unique to the processing execution node, control information, and response information of the processing result. .

The second method is an individual communication method. request/
The format of the request message is basically the same as that of the first method, but the processing request node transmits the request message by designating the node address unique to the processing request destination node as the transmission destination address, and then transmitting the request message. The application program of the specific node designated by the destination address executes the process and returns a response message. The processing request node that received the response message confirms that the source node address in the response message is the processing request destination node designation, and fetches the response message.

[0005]

According to the first method of the prior art, although a highly reliable system can be constructed by the duplicate execution by the nodes having the same function code, the function code is included in the processing request information in the processing request message. Therefore, it is uneconomical because the application programs of all the nodes or a part of the nodes once fetch the request message and judge whether the request message can be executed.

Further, according to the second method, when the application program of the node requested to process the destination individual node address in the request message is abnormal (fault / overload), it has the same function as that node. On the node,
The processing request destination must be changed. In this case, or when adding the same function as the processing request destination to another node or adding a node having the same function to the system,
There was a problem that the destination node information had to be updated each time.

An object of the present invention is to provide a message communication system that solves the problems of the above-mentioned first and second conventional systems in a distributed processing system in which a plurality of nodes are connected via a transmission line. .

[0008]

In order to achieve the above object, the present invention provides a transmission path control means for controlling an electric signal interface with a transmission path of each node, and a communication control processing for performing communication protocol processing and the like. When the node sends a request message for processing request to and from the means, the function address corresponding to the desired processing type in the request message is added to the request message, and the destination in the request message is added. When the node holds the address and the node transmits a response message corresponding to the request message, means for transmitting the destination address of the response message by specifying the node address unique to the request message source node,
When the request message is received, if the functional address in the request message indicates a functional address corresponding to the processing type that can be processed by the node, the received request message is fetched and the functional address in the request message is read. When deleting and changing the destination address in the request message to the address for the node and receiving the response message corresponding to the transmitted request message, the source node address in the response message is changed to the response message. And means for changing to the destination address held when the request message corresponding to is transmitted.

Further, the present invention adds means for temporarily holding a response message group returned by each of a plurality of nodes with respect to a request message transmitted by the node and selecting a valid response message from the response message group. It is characterized by

[0010]

According to the present invention, when transmitting a request message for a processing request, a functional address is added to the request message and transmitted, and each node that matches the functional address receives the request message. The node that fetches the request message deletes the functional address from the request message and converts the destination address in the request message to the address addressed to itself (in the case of a global address, the group address including the own node If not necessary),
Send the received request message to the application program. As a result, the application message of each node in which the destination address in the request message matches the function address added to the request message regardless of the finger of the global / group / individual node address Execute the process as if it were addressed to you and return the response message.

Upon receiving the response message, the processing request node side changes the source node address in the response message to the destination address at the time of transmitting the request message corresponding to the response message. As a result, the response message from each node that matches the functional address added to the request message is sent to the node of the destination address specified in the request message regardless of the destination address in the corresponding request message. Can be submitted to the requesting application program as from.

Further, the processing request node selects a legitimate response message from a plurality of response messages returned from each node that matches the functional address and sends it to the request source application program. As a result, the validity of the response message is guaranteed even if the error response message is returned from some of the request destination nodes.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

<Embodiment 1> In Embodiment 1, as shown in FIG. 2, a plurality of nodes (computers) 110, 120, ...
Is for a system configuration directly connected via the transmission path 100.

FIG. 1 is a diagram showing an example of a node configuration in this embodiment. In the figure, the node 110 comprises an application program 111, a communication control processing means 112, a transmission path control means 113, a function address adding means 114, an address changing means 115 and a message selecting means 116. The configuration of the node 120 is similar to that of the node 110. Although only the nodes 110 and 120 are shown here,
A plurality of nodes having the same configuration are connected to the transmission line 100.

FIG. 3 shows a format example of the request message and the response message of the present invention. FIG. 3A shows a request message, which is a functional address 210, a transmission destination address 211, a transmission source address 212, control information 213, and a request information body 2.
It consists of 14. Here, the destination address 211 can be arbitrarily designated as a global address for all nodes, a group address for some nodes, or an individual node address. Source address 212
Is a node address specific to the request message transmission source node. The control information 213 is information for communication protocol processing and the like. The request information body 214 includes a function code corresponding to the desired processing type and processing request contents. The structure of these 211 to 214 is basically the same as the conventional request message, and the function address 2 is added in the present invention.
It is 10. In the function address 210, a function code in the request information body 21 in the request message or a code similar thereto (processing type code) is set as a kind of destination address. FIG. 3B shows a response message, which includes a destination node address (request message transmission source node) 221, a transmission source node address (the response message transmission source node) 222, control information 223, and a response information body 224. The structure of the response message is basically the same as the conventional one.

In FIG. 1, the node 110 is a processing request node and the node 120 is a processing execution node.
The operation of the first embodiment will be described.

A request message issued by the application program 111 of the processing request node 110 is sent to the functional address adding means 114 via the communication control processing means 112.
To receive. The request message received by the functional address adding means 114 has the configuration of 211 to 214 in FIG. Here, the application program 111 is free to set the destination address 211 to global address designation, group address designation, or individual node address designation. The source address 212 is
Naturally, the unique node address of the processing request node 110 is designated. The functional address addition means 114 uses the destination node address (global /
(Group / individual node address) is held, and a function address corresponding to the function code (desired processing type) of the processing request body 214 in the request message is added to the request message and transmitted via the transmission path control means 113. Send to path 100. As a result, 210-2 of FIG.
The request message with the functional address having the structure of 14 is the transmission line 1
00 is propagated to all nodes connected to 00 (broadcast).

In the processing execution node 120, the address changing means 125 receives the request message with the functional address via the transmission path control means 123. The address changing unit 125 holds the function address corresponding to the processing type that can be processed by the node, and sends the request message only when the function address in the received request message matches the held function address. If it does not match and is not matched, the received request message is sent to the transmission path 100 via the transmission path control means 123 as it is. The address changing unit 125 also holds an abnormal state (fault, overload, etc.) of the own node 120, and if the own node is in an abnormal state, even if the functional address matches, the received request message remains as it is. It returns to the transmission path control means 123.

When the request message is fetched, the address changing means 125 deletes the function address in the request message, and when the destination address 211 in the request message does not specify the own node 120, The address is changed to the address addressed to the own node 120, and the request message is passed to the message selecting means 126. As a result, the request message passed from the address changing unit 125 to the message selecting unit 126 is 211 to 214 in FIG.
In addition, the transmission destination address 211 is always the address designation for the own node 120. Message selection means 1
26 directly sends the passed request message to the communication control processing means 122, and the communication control processing means 122
Since the destination address in the request message is addressed to the own node, the request message is sent to the application program 121.

The application program 121 executes the request content of the received request message, and the functional address adding means 124 receives the corresponding response message via the communication control processing means 122. The response message has the configuration of 221 to 224 in FIG. here,
The transmission destination address 221 is the designation of the unique node address of the request message transmission source node 110 corresponding to the response message, and the transmission source address 222 is the designation of the unique node address of the own node 120. Functional address adding means 124
If the received message is a response message, then sends the response message as it is to the transmission path 100 via the transmission path control means 123.

Similarly, in each node other than the node 120, a node group having a functional address (processing function) that matches the functional address added to the received request message fetches the request message, The requested content is processed and executed, and the corresponding response message is sent to the transmission path 100.

In the processing request node 110, the address change means 115 receives the response message via the transmission path control means 113. When the address changing unit 115 receives the response message corresponding to the request message transmitted by the node 110, the address changing unit 115 sets the source address 222 in the response message to the functional address adding unit when transmitting the request message corresponding to the response message. The address is changed to the transmission source address held by 114 and passed to the message selection means 116. The address changing unit 115 performs the same process for each received response message and matches with the corresponding request message. The message selecting means 116 temporarily holds the response message passed from the address changing means 115, and when the number of response messages for the same processing request exceeds a predetermined number, selects a highly valid response message from among them and communicates the message. It is sent to the control processing means 112. The communication control processing means 112 sends the response message to the application program 111.

In the application program 111,
It is confirmed that the source address in the response message is the source address of the processing request message, and it is determined that the response message is from the request destination node.

FIG. 4 shows an example of the processing flow of the functional address adding means when transmitting the request message and the response message.

When sending a request message for a processing request,
The functional address addition means (for example, 114 in FIG. 1) receives the message from the communication control processing means (112) (step 301), determines the information type (request / response) in the message (step 302), Since it is a request, the destination address in the request message is held (step 303), and the function address corresponding to the desired processing type (function code) of the request information body in the request message is added to the request message. (Step 30
4), and transmits to the transmission path control means (step 305).

On the other hand, when transmitting a response message corresponding to the received request message, the functional address adding means (for example, 124 in FIG. 1) is connected to the communication control processing means (same as above).
2) Information type in the response message received from (request /
Response), and since it is a response, the response message is transmitted to the transmission path control means (step 123) (step 30).
6).

FIG. 5 shows an example of the processing flow of the address changing means when receiving the request message and the response message.

When the request message is received, the address changing means (for example, 125 in FIG. 1) is connected to the transmission line control means (see FIG.
3) The message is received from (step 401), the information type (request / response) in the message is determined (step 402), and since it is a request, the functional address in the request message and the address changing means hold it. It is compared with the functional address to be processed (step 403), and if they match, the received request message is fetched. Then, the functional address in the request message is deleted, the destination address in the request message is changed to the address addressed to the own node (step 404), and the message selecting means (same as above).
6) (step 405). If the destination address in the fetched request message is an individual address addressed to the own node from the beginning, if it is a global address for all nodes, or if it is a group address including the own node, no address change is required. . If the function addresses do not match as a result of the comparison in step 403,
The request message is not captured.

On the other hand, when the response message corresponding to the transmitted request message is received, the address changing means (for example, 115 in FIG. 1) determines the information type (request / response) in the received message and the response is a response. , The source node address in the response message is changed to the destination address held in step 303 by the functional address adding means (at step 114) when the request message corresponding to the response message is transmitted (step 406), and the response message is returned. To the address selecting means (116).

FIG. 6 shows an example of the processing flow of the message selecting means when the request message is received and the response message is received.

When receiving the request message, the message selecting means (for example, 126 in FIG. 1) is changed to the address changing means (same as in FIG.
The message is received from 5) (step 501), the information type (request / response) in the message is determined (step 502), and since it is a request, the request message is passed to the communication control processing means 122 as it is.

On the other hand, when the response message is received, the message selection means (for example, 116 in FIG. 1) uses the information type (request / request / request) of the message from the address changing means (115).
Response), and since it is a response, it is determined whether the response processing of step 507 has already been completed for the processing request corresponding to the response message (step 504), and if completed, it is not taken. If not completed, first, the number of received response messages for the same processing request is determined, and the response messages are temporarily held (step 505). Next, in the case where two response messages have already been held for the same processing request, the majority of the information in these three response messages including the newly held response message is executed, and a highly valid response message is obtained. It is determined (step 506). Then, the determined response message is transmitted to the communication control processing means (at 112), the retained response message is cleared, and the response completion state is retained (step 507). When it is determined in step 505 that the number of held and received response messages for the same processing request is one or less, the next response message is awaited.

In FIG. 6, in response to the same processing request, response messages from three processing execution nodes are received, and a response message with a high degree of validity is determined by majority decision of the three response messages. It doesn't have to be one. It should be noted that the case where the final reception response message is 2 or less for the same processing request will be described with reference to FIG. 7.

FIG. 7 is an example of a flowchart of post-processing of the message selecting means on the processing request node side.

Message selecting means (for example, 11 in FIG. 1)
6) measures the elapsed time from the transmission of the processing request message by an instruction or the like from the communication control processing means (112) (step 601), and determines the elapsed time and the maximum response time of the processing request (the communication control processing means It is compared with the maximum response time that is set) (step 602). And
If the maximum response time is not exceeded, do nothing. on the other hand,
When the maximum response time is exceeded, the response completion state corresponding to the processing request is determined (step 603). When the response is completed, the response completed state is cleared (step 60).
4). If the response is incomplete, if there is a retained response message to the processing request, it is transmitted to the communication control processing means, and then the retained response message is cleared (step 605). At this time, if there is only one held response message for the same processing request, it may be passed to the communication control processing means.
It is specified that the response message received earlier or later is passed.

If the application program side selects a legitimate response message from a plurality of nodes for the same processing request, the message selecting means is unnecessary.

In order to increase the response time, the message selecting means may transmit the first received response message to the communication control processing means and ignore the subsequent response messages.

<Embodiment 2> In the embodiment 2, as shown in FIG. 8, a plurality of nodes 110, 120, ..., Via network control devices (NCE) 810, 820 ,.
It is intended for system configurations connected by the transmission path 100.

FIG. 9 is a block diagram of the second embodiment. That is,
In the second embodiment, the functional address adding means, the address changing means, and the message selecting means described in the first embodiment are provided in each NCE.

FIG. 9 is shown in correspondence with FIG.
When the node 110 is the processing request node and the node 120 is the processing execution node, the function address adding means 814 or 824, the address changing means 815 or 825 in each of the NCEs 810 and 820 connected to the nodes 110 and 120, and the message Selection means 816 or 8
The operation of 26 is exactly the same as that of the first embodiment.

[0042]

According to the message communication system in the distributed processing system of the present invention, the following effects can be obtained.

(1) Since the request message is fetched in advance only in the node capable of executing the process corresponding to the desired process type, and the response message is fetched in only the request source node, all nodes or some nodes The application program does not need to determine the execution once it is loaded, which is economical and improves the processing performance of each node.

(2) Since the processing request message is transmitted by using the functional address as a kind of destination address, when the application program of the destination node is abnormal (fault / overload, etc.), it is sent to another node having the same function as that node. It is not necessary to change the processing request destination. Moreover, even if the same function as that of the processing request destination is added to another node or a node having the same function is added to the system, it is not necessary to update the destination node information each time, so system reliability is improved. , Maintainability and scalability are improved.

(3) Even when NCEs are connected to each node and these NCEs are connected to a transmission line having a broadcast function, the devices constituting the system are changed regardless of the communication method between the nodes. Without doing so, the effects of the above (1) and (2) can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a schematic block diagram of a distributed processing system which is a target of the first embodiment of the present invention.

FIG. 3 is a format example of a request message and a response message according to the present invention.

FIG. 4 is an example of a processing flow of a functional address adding unit 1 in FIG.

5 is an example of a processing flow of address changing means in FIG.

FIG. 6 is an example of a processing flow when a response message is received by the message selecting means in FIG.

FIG. 7 is an example of a post-processing flow of message selection means in FIG.

FIG. 8 is a schematic block diagram of a distributed system targeted by the second embodiment of the present invention.

FIG. 9 is a configuration diagram of a second embodiment of the present invention.

[Explanation of symbols]

 100 transmission line 110, 120 node 111, 121 application program 112, 122 communication control processing means 113, 123 transmission line control means 114, 124 functional address adding means 115, 125 address changing means 116, 126 message selecting means

Claims (2)

[Claims] 1. In a distributed processing system in which a plurality of nodes are connected via a transmission path, a transmission path control means for controlling an electric signal interface with a transmission path of each node, and a communication control processing means for performing a communication protocol processing and the like. When sending a request message for a processing request between the node and, the function address corresponding to the desired processing type in the request message is added to the request message, and
A means for holding the destination address in the request message and transmitting the response address of the response message by specifying the node address unique to the request message source node when the node transmits the response message corresponding to the request message. When a request message is received, if the functional address in the request message indicates a functional address corresponding to the processing type that can be processed by the node, the received request message is fetched and the functional address in the request message is received. When the response message corresponding to the transmitted request message is received and the destination address in the request message is changed and the response message in the response message is received, the source node address in the response message is changed to the response. Destination saved when sending the request message corresponding to the message A message communication method characterized by including means for changing to an address. 2. The message communication method in the distributed processing system according to claim 1, wherein a response message group returned by each of a plurality of nodes with respect to a request message transmitted by the node is temporarily retained, and the response message group is transmitted from the response message group. A message communication method characterized by adding means for selecting a valid response message.