JPH0621925A - Communication control system for multiplex transmission line - Google Patents

Abstract

PURPOSE:To prevent the deterioration of throughput of a transmission line by deciding the redundant messages and disposal processing through a communication control adaptor. CONSTITUTION:The nodes 1a-1c are connected for multiplication to the LAN 2a-2b via the transceivers 3a-3c and 4a-4c. A communication control adaptor is provided on each multiplexed transmission line for the transfer control of messages together with a common memory. This memory stores the information necessary for detection of the redundant messages. The precedently received message if decided is transferred to a processor, and the subsequently received message is discarded. Thus the redundant messages are decided (and discarded) by the control adaptor so that the number of receiving interruptions inputted to the processing operation is equal to that required for a single transmission line. Therefore it is possible to prevent the increase of interruptions applied to the processor due to the multiplexed transmission line and then to prevent the deterioration of throughput of the transmission line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a distributed system in which a plurality of information processing devices perform message communication using a transmission line such as a LAN and cooperate with each other to perform processing. Therefore, it relates to the communication control method when the transmission lines are multiplexed, in particular, the same message is redundantly transmitted to the multiplexed transmission lines, and the receiving side takes the first-arrival message in the information processing device Relates to a discarding parallel multiplex communication method.

[0002]

2. Description of the Related Art In a conventional parallel multiplex communication method, for example, as shown in the transmission system of a duplex transmission line described in Japanese Patent Laid-Open No. 3-178234, all messages are transmitted from the multiplexed transmission line. It was input to one processing device, and the duplicate message was judged and discarded there.

[0003]

In the above-mentioned conventional method, the reception interrupts from the multiplexed transmission lines are all included in one processing unit. Therefore, although the reliability of message communication is improved as compared with the case where there is a single transmission path, the load of reception processing increases due to the multiplexing of the transmission paths, and as a result, the throughput of message transfer between information processing devices increases. There was a problem that it would decrease.

[0004]

In order to solve the above problems, in the present invention, a communication control adapter for controlling message transmission / reception is provided on each of the multiplexed transmission lines, and the communication control adapters are commonly shared by the communication control adapters. A memory is provided so that information necessary for message duplication detection is stored therein, and each communication control adapter refers to the shared memory to determine whether the received message is a duplicate message or not It is characterized in that the message is transferred to the processing device, and the received message determined to be the last arrival is discarded.

[0005]

According to the above configuration of the present invention, since the communication control adapter determines and discards the duplicate message, the number of reception interrupts input to the processing device is the same as when the transmission line is single. Become. Therefore, the number of interrupts to the processing device does not increase due to the multiplexing of the transmission lines, and it is possible to prevent the throughput of the transmission lines from decreasing.

[0006]

FIG. 2 is a block diagram of a distributed processing system to which the present invention is applied, in which a plurality of nodes 1a to 1c are connected to a plurality of LANs 2a to 2b and transceivers 3a to 3c.
And 4a to 4c. The reason why the LAN connecting the nodes is multiplexed in this way is to make the message communication between the nodes highly reliable.

FIG. 3 is a diagram showing an internal hardware configuration of the node 1, in which a CPU 11, a main memory (hereinafter abbreviated as MM) 12, and communication control adapters 13a and 13b are connected by a bus 14. Here, the communication control adapter is provided for each of the multiplexed LANs 2a to 2b and is connected to each transceiver.

FIG. 4 shows a software configuration diagram in the MM. Reference numerals 51a to 51b and 52a to 52b are business processing tasks, 53a to 53b are reception message queues used when inputting a reception message to the business task, and 54.
Is started when the business processing tasks 51a and 51b send messages to business processing tasks of other nodes,
A transmission processing module that controls each communication adapter to redundantly transmit a message to a multiplexed LAN, 55 is a transmission serial number management table that manages a serial number added to a transmission message, and 56 is transmission / reception to / from a communication control adapter System buffer for storing messages, 57a-
57b is a transmission interface queue that is provided for each communication control adapter and serves as an interface between the transmission processing module 54 and the communication control adapter, and 58a to 58b.
Is a reception interface queue for the communication control adapter to register the address and data length of the received message,
Reference numeral 59 is a reception sequence number management table that each communication control adapter refers to for duplicate message reception check processing,
Reference numeral 60 denotes a reception processing task that takes out a reception message registered in the reception interface queue, registers the reception message in the reception message queue for the business processing task, and activates the business processing task. Reference numeral 61 denotes management of tasks in the system. A supervisor that manages interrupt processing from the communication adapter.

FIG. 5 is a block diagram of the internal hardware of the communication control adapter, which includes a CPU 71, a bus interface unit 72 for connecting the bus 14 and an internal bus 75 in the communication control adapter, and communication for controlling message transmission / reception with a LAN. The control unit 73 and a local memory (hereinafter abbreviated as LM) 74 are shown.

FIG. 6 is a software configuration diagram in the communication control adapter LM. The transmission control task 81, the reception control task, the transmission / reception buffer 83, the address conversion table 84,
Then, it is shown that it is composed of the supervisor 85.

Next, the message transmission process will be described with reference to FIGS.

FIG. 7 is a flowchart of the transmission processing module 54. This module is an address and data length of transmission data, and a transaction code (hereinafter TCD: Transaction Coding) indicating the type of data.
When the business processing task is started with an argument (de abbreviated) as an argument, first, a free buffer is secured from the system buffer 56 to transfer the transmission data designated by the business task into the system buffer (processing 101). Figure 8
Is edited (process 102). In FIG.
Reference numerals 201 to 205 are areas forming a header portion of a message, and reference numeral 206 is a data body requested to be transmitted by a business processing task. In the header part, 201 is an area for setting the data length (L) of the message including the header part, and 202 is the source node address (SA: Source).
ce Address) is set in the area 203, and the destination node address (DA: Destination) is set.
nAddress) is set in an area, 204 is an area in which a serial number (SEQ) is set, and 205 is an area in which a TCD designated by an argument by a business task is set.

Of the above headers, the serial number SEQ is set by referring to the transmission serial number management table 55. FIG. 9 shows the structure of the serial number management table. This table is provided with an entry corresponding to each node in the system, and each entry 301, 302, 303 stores a transmission serial number when a message is transmitted to the node. In the transmission message editing process 102, this transmission sequence number is set in the header, and the value of the sequence number in the table is counted up. Next, in order to input a transmission message to the communication control adapter provided for each LAN, create as many control blocks as the number of communication control adapters in which the address and data length of the system buffer storing the transmission message are set ( (Process 103) and sequentially register in the transmission interface queue (Process 10)
4). By the above processing, the transmission data requested by the business processing task is registered in the communication control adapter of each LAN.

The message registered in the transmission interface is sent to the transmission control task 81 in the communication adapter.
Is taken out and sent to the LAN. That is, the transmission control task 81 is periodically activated by the supervisor 85 and executes the processing flow shown in FIG.

First, the transmission interface queue corresponding to the self-adapter is referenced to check whether or not the control block is registered (process 401). If not registered, the process ends. If the control block is registered, it is taken out from the queue (process 402) and transferred from the system buffer to the LM internal receive buffer 83 according to the address and data length set in the control block (process 403). Next, the physical address corresponding to the DA in the header is converted into the address conversion table 8
4 is obtained (process 404). Then, the communication control unit is activated with the address, data length and destination physical address of the transmission message as input parameters, and the message is sent to LA.
While sending to N, the process returns to the process 401. LA above
The transmission processing to N is executed in parallel for each communication control adapter, and as a result, the message of the same content is redundantly transmitted to each LAN.

Next, the process of receiving a message from the multiplexed LAN in each node will be described with reference to FIGS. 1 and 11-12.

When a message is received from the LAN, the communication control unit 73 in the communication control adapter transfers the received message to the transmission / reception buffer 83 and activates the reception control task 82 via the supervisor 85. At this time, the address and data length of the received message are input to the reception control task as start parameters.

When activated, the reception control task executes the processing shown in FIG. First, SA and SEQ are read from the header of the received message (process 501). Next, the bus 14 is occupied and locked to access the reception serial number management table in the MM (process 502). This is to prevent the reception serial number management table from being simultaneously accessed and updated by another communication control adapter and destroying the consistency of the table contents.

FIG. 11 is a diagram showing the structure of the reception sequence number management table. A field 601 (hereinafter referred to as the latest reception sequence number) stores and manages the sequence number of the latest message received from the node according to the message transmission source address. , R
_SEQ), 602 and 603. From this reception sequence number management table, R_SEQ is read from the entry corresponding to SA (process 503),
Compare with the SEQ of the received message header (process 5)
04). If the SEQ is larger than R_SEQ and the message is a first-come-first-served message, the SEQ of the message just received is set in the reception sequence number management table and updated (process 50
5) An unlock process for releasing the occupied bus is performed (process 506). Then, a free buffer is secured from the system buffer in the MM, the received message in the LM is transferred (process 507), and a control block in which the address and the data length of the transfer destination system buffer are set is created to support the own adapter. It registers in the reception interface queue (process 508), interrupts the CPU 11 (process 509), and ends the process. S in the above processing 504
If the EQ is less than or equal to R_SEQ, it is a duplicate message that has already been received, and after the bus unlock process (process 510), the received message is discarded (process 511) and the process ends. Through the processing of the reception control task in the communication adapter as described above, the message received from the LAN is transferred to the MM only when the message arrives first, and the CPU 11 receives the reception interrupt. Therefore, even if the LANs are multiplexed, the number of interrupts entering the CPU 11 is the same as when the LAN is single.

When receiving an interrupt from the communication control adapter, the supervisor 61 activates the reception processing task 58 in the MM with the number of the communication control adapter that has inserted the interrupt as a parameter. When the reception processing task is activated, it executes the processing of the flow shown in FIG. That is, it is first checked whether or not the control block is registered in the reception interface queue corresponding to the communication control adapter designated by the parameter (process 701). If it is registered, the control block is taken out from the head of the queue (process 702), the header of the received message in the system buffer is accessed from the address set therein, and the TCD is read (process 703). And TC
According to D, the control block is registered in the business task reception queue and the business task is activated (process 70).
4) and returns to process 701. If the control block is not registered in the reception interface queue in process 701, the process ends. When the business processing task is activated by the reception processing task, it retrieves the received message from the reception queue and executes the business processing according to the TCD.

[0021]

According to the present invention, the information processing devices are
In a communication system in which the same message is redundantly transmitted and received via a multiplexed transmission line and only the first-arrival message is selectively taken in at the receiving side, an increase in the reception processing load of each information processing device is suppressed and performance is reduced. It is possible to realize highly reliable message communication without any need.

[Brief description of drawings]

FIG. 1 Flowchart of reception control task

[Figure 2] Application system configuration diagram

FIG. 3 is a hardware configuration diagram of a node

[Figure 4] Software configuration diagram in the main memory

[Figure 5] Hardware configuration of communication control adapter

FIG. 6 Software configuration diagram in local memory

FIG. 7 is a flowchart of a transmission processing module.

[Figure 8] Message format

FIG. 9 is a configuration diagram of a transmission serial number management table

FIG. 10 is a flowchart of a transmission control task.

FIG. 11 is a configuration diagram of a reception serial number management table.

FIG. 12 is a flowchart of a reception processing task.

[Explanation of symbols]

 MM ... Main memory LM ... Local memory TCD ... Transaction code L ... Message length SA ... Source node address DA ... Destination node address SEQ ... Serial number R_SEQ ... Latest Received serial number

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Wataya 5-2-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Omika Plant (72) Inventor Kenji Kataoka 1099 Ozenji, Aso-ku, Kawasaki-shi, Kanagawa Hitachi Ltd. System Development Laboratory (72) Inventor Osamu Takada 1099 Ozenji, Aso-ku, Kawasaki City, Kanagawa Prefecture Hitachi Systems Development Laboratory (72) Inventor Kenji Matsuzaki 5-2 Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 in Hiritsu Process Computer Engineering Co., Ltd. (72) Inventor Haruo Tsuzuki 52-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hiritsu Process Computer Engineering Co., Ltd.

Claims (2)

[Claims] 1. In a communication system for transmitting and receiving a message through a plurality of transmission lines in which a plurality of information processing devices are multiplexed, each information processing device is provided for controlling transmission and reception of messages provided corresponding to the transmission lines. Multiple communication control devices and a shared memory for storing message duplication determination information commonly referred to and updated by the plurality of communication control devices, and each information processing device serving as a message transmission source is the same. If each communication control device that has sent a transmission message to the above multiple transmission lines and has received the message from the above transmission lines accesses the shared memory to determine the duplication of the received message, and if the received message is not a duplicate message, the information A multiplex transmission line communication control method characterized by taking in a processing device and discarding duplicate messages. 2. When a plurality of information processing devices are connected to a plurality of transmission lines and each information processing device redundantly sends the same message to a plurality of transmission lines and receives the message from the transmission lines, only the first-arrival message is sent. This is a method of capturing in the device and discarding the duplicate message of the last arrival. Even if the multiplicity of the transmission line is increased, the number of message reception interrupts to the CPU in the information processing device is the same when the transmission line is single. A multiplexed transmission line communication control method characterized by being the same.