JPH07104840B2 - Backup method for distributed system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a backup method for a distributed system using a network, and particularly when a redundant system is provided, automatic backup is performed with high reliability by broadcast communication. In addition, the present invention relates to a backup method of a distributed system that can easily cope with system modification.

[Conventional technology]

In recent years, with the development of micro computers and local area networks, distributed data processing systems using micro computers have become the mainstream of equipment control. The distributed data processing system emphasizes the flexibility of system construction and the low price of the system. On the contrary, since the system is distributed, it is necessary to improve the continuity of data and the reliability of the system. is there.

To deal with these problems, the important processor in the system configuration is duplicated so that the data between the two processors can be matched (see JP-B-61-18786, JP-B-61-19060), and on the transmission line. There is one that realized the continuity of the data of (see Hitachi internal GP59-160014).

[Problems to be solved by the invention]

FIG. 7A shows that a network having a broadcast communication function is used as the transmission line 10, and the transmission line 10 includes data processing devices 20B and 20C, and a data processing device 20A _{1 having} a dual system configuration.
20A ₂ is the connected system. Here, for example, when the data processing device 20B sends the data D ₁ and when the data processing device 20A ₁ sends the data D ₂ , the data is guaranteed and the data is passed to the terminal 401. However, when dozens of terminals 401 to 40n are connected on the network, from the viewpoint of terminal responsiveness, these terminals are connected to the data processing devices 20B to 20Z as shown in FIG. 7B, and the data processing devices are connected. The load on the can be reduced. However, in this configuration, the data processing apparatus 20B may down after receiving the data D _3, because the data processing apparatus 20B is not duplicated, a problem that the data D ₃ can not reproduce it is lost has been made. Furthermore, in the distributed network processing system, (1) it is possible to create software that does not consider the physical location and state of the terminal. (2) There is a demand for being able to flexibly cope with the stepwise construction and modification of the system, but these cannot be satisfied by the conventional technology.

The object of the present invention is to solve the above-mentioned problems of the prior art, and even if one processing unit goes down, its function can be automatically backed up immediately and the software can be created. There is a need to provide a backup method for a distributed system that does not need to be aware of the physical location of terminals and can flexibly respond to system changes.

[Means for solving problems]

The above-mentioned purpose is to divide the terminal into functional group units and give logical terminal numbers, and to provide each data processing unit with a backup data acquisition module for this functional group unit, and to perform this function module when broadcast communication is performed. The backup data is acquired by the above method, and when any one of the data processing device abnormalities is detected, the data is backed up to a terminal connected to another data processing device and having the same function.

[Action]

A functional group unit of a terminal is composed of one or more physical terminals connected to the same data processing device, and has a unique (only one throughout the distributed network) logical terminal number for the group. In the application software, if this logical terminal number is designated according to the required function and the processor assigns it to the actual terminal, the software need not be aware of the physical terminal state.

Furthermore, the backup data acquisition module is a function that realizes automatic backup of terminals in the same data processing device and automatic backup of data between other data processing devices, and also constructs and repairs a distributed network processing system in stages. It is also a function that can support functions that are lost due to automatic back-up processing.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to examples. FIG. 2 shows an example of a distributed network to which the method of the present invention is applied. Data processing devices 20B to 20Z are respectively connected to terminals, and these terminals have the same function (or related to the arrangement). ) Are grouped into a group surrounded by a dotted line so that the logical group numbers 301, 302,
......, 30n is given. 4 for terminals in each group 30i
0ia, 40ib, ..., Physical terminal numbers are attached.

FIG. 1 is a diagram showing a software configuration 50 of the data processing device 20B shown in FIG. 2 described above, and other data processing devices have the same configuration. Inside the software 50, a backup data acquisition module 55, a terminal function type table 52 defining a correspondence between a logical terminal number of a terminal displaying the data 51 and a physical terminal number and a function pattern, and a table 54 between data processing devices. It also includes a terminal backup table 53 and other software module groups 56 (which are irrelevant to the present invention).

FIG. 3 shows a detailed example of the function type table 52.
It is a definition table that facilitates system modification according to the terminal status and the number of terminals with application software. The application linkage is performed by the logical terminal numbers 301 to 303, and the table 52 is referred to according to the content of the data 51, and the data output terminal can be determined by the function type corresponding to the physical terminal numbers 401a to 403a. In other words, it is possible to logically output data to the terminal by ignoring the physical terminals at all, and grouping by the function classification unit of the terminal or the arrangement related unit of the terminal.

FIG. 4 is a flowchart of the processing of the backup data acquisition module 55. At step 100, the logical terminal number and the function type in the data are fetched, and the physical terminal number corresponding to this is determined by referring to the table 52. Step 102
Then, it is checked whether or not the determined terminal is normal, and if normal, data is output in step 103. If it is not normal, the terminal function type table 52 is referred to again in step 104, another terminal having the corresponding function is determined, and the data is output to the terminal in step 105. With such a mechanism,
Even when the number of physical terminals is increased or decreased, it can be dealt with only by modifying the terminal function type table 52, and there is no need to modify the application software of the distributed network system, which enables flexible correspondence.

FIG. 5 shows the contents of the data processing unit table 54. This table is stored in all the data processing devices that make up the network, and is for allowing any data processing device in the network to support the functions of other data processing devices. In the case of the data processing device 20B, the logical terminal number corresponding to its own processing device number 20B is 301-
Three of 303, similarly two of the logical terminal numbers 304 and 305 in the case of the data processing device 20C, and so on.
The terminal 304 or the one connected to it when C goes down
When the data processing device 20B backs up 305, the terminal
It shows that it is according to 301 or 302. Other entries in the table 54B, other tables 54D, 54Z, etc. have the same meaning.

FIG. 6 is a flow chart of the backup processing in the function module 55. First, in Steps 110 and 111, the own data processing apparatus number and the logical number of the terminal connected to the own apparatus are fetched, and then in Step 112 the data processing to be backed up. By referring to the inter-data processing device table 54 from the device number and the own device number, the logical number of the terminal used for the backup is determined. As a result, even when the non-redundant data processing devices 20B to 20Z are down, backup by another device is possible. Even when constructing a distributed network system step by step, it is possible to back up data to unconfigured data processing devices.

〔The invention's effect〕

According to the present invention, in a distributed network processing system, there is an effect that an automatic backup is possible when the data processing device is down, and it is possible to easily cope with the stepwise construction of the network system and further There is also the effect that Yong Software does not need to be aware of the physical location or state of the terminal.

[Brief description of drawings]

FIG. 1 is a diagram showing a software configuration of a data processing device for realizing the method of the present invention, FIG. 2 is a diagram showing an example of a distributed network to which the present invention is applied, and FIG. 3 is a function type table. FIG. 4 is a flow chart of the function type processing unit of the backup data acquisition function module.
FIG. 5 is a diagram showing an example of a table between data processors, FIG.
FIG. 7 is a flow chart of the logical terminal number acquisition processing unit of the backup data acquisition function module, and FIGS. 7A and 7B are views showing a conventional distributed network. 10 ... Transmission path, 20A-20Z ... Data processing device, 301-30n
…… Logical terminal number, 401a-40nm …… Physical terminal number, 51…
… Data, 52 …… Terminal function type table, 54 …… Data processing device table, 55 …… Buckup data acquisition function module.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-59-206973 (JP, A) JP-A-60-173654 (JP, A) JP-A-61-90254 (JP, A) JP-A-54- 18252 (JP, A)

Claims (1)

[Claims] 1. A transmission line having a broadcast communication function, a plurality of data processing devices connected to the transmission line for transmitting and receiving data by broadcast communication, and a physical unit unique to each of the data processing devices. In the backup method of a distributed system consisting of numbered terminals, the terminals connected to each data processing device are divided into groups according to their functions, and a logical number is assigned to each group, and A first table showing the correspondence between the function and physical number of each connected terminal and the logical number given to the group to which the terminal belongs, and an arbitrary one and the terminal connected to the data processing device When an arbitrary data processing device backs up by a terminal connected to its own device, the correspondence relationship between the backed up terminal and the backed up terminal is described. Each data processing device is provided with a second table indicated by a logical number, and whether or not there is an abnormality in the data processing device that is transmitting from one of the data processing devices by the broadcast cast and should receive the transmission data. In the case of connection, one of the other data processing devices refers to the second table to determine which logical number of the terminal group of the own device should be backed up, and further the determined logical number and its When the function of the terminal to give the received data is specified, or the logical number of the terminal to be used and the function of the terminal to give the received data by the data sent by the broadcast cast from another data processing device to the own device Is specified, the first table is referred to, which physical number is used to determine which terminal to use, and the received data is sent to that terminal. Batsukuatsupu method of distributed system is characterized in that so as to force.