JPS60136452A - Stand-by switching control system - Google Patents

Abstract

PURPOSE:To perform stand-by switching control with an inexpensive and simple constitution by providing a command concerning stand-by switching control in a channel interface and decoding and executing this command in a stand-by communication controller. CONSTITUTION:A stand-by switching control system is constituted of a host processor 1, current communication controllers 2, a stand-by communication controller 3, a line changeover switch 5 which switches communication line interfaces 106 to the current device or the stand-by device, and a stand-by switching additional mechanism 6. The host processor 1 and communication controllers 2 and 3 are connected to a channel interface 101. Normally, this interface 101 is used mainly for line data transfer. The command for stand-by switching is provided newly as a channel command, and this command is decoded and executed by the stand-by communication controller 3.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to standby switching control of a communication control device, and in particular to switching between an active communication control device and a standby communication control device without manual intervention by a command from a host processor. The present invention relates to a standby switching control method suitable for an automatic standby switching system.

[Background of the invention]

Communication control devices are highly important in online systems. Therefore, in order to minimize the effects of a communication control device going down, a system configuration is adopted in which a backup communication control device is prepared and the system is switched to the backup system in the event of a failure. This operation of switching to the standby system must be performed in the shortest possible time and without any errors. To achieve this,
Automatic switching is being considered in which switching is performed without manual intervention based on commands from a control program in a host processor. The conventional automatic switching system and its problems will be explained below.

FIG. 1 is a block diagram of a conventional system for realizing automatic switching. This system consists of a post processor 1. Current communication control device! i2. 5. A line changeover switch that switches the communication line interface 106 of the standby communication control device 31 to either the active side or the standby side. The system console 4 also includes a system console 4 which receives a direct control signal 102 from a host processor and issues a switching command to a communication control device 2.5 and a line changeover switch 5.

Control signals 103 and 104 from the system console 4 to each communication control device send each communication control device to the BN
This is to instruct whether to select ABB or DISABLE. A channel interface 101 connects the host processor 1 and the communication control devices 2 and 3. On the other hand, for control of backup switching, a direct control interface 102 is provided between the host processor and the system console 4 in addition to the channel interface. The system console 4 decodes the switching instruction given to the direct control interface 102 and sends switching instructions 105, 104 to the communication control device and a switching instruction 105 to the line changeover switch.

In this system, the procedure from detection of a fault in the active communication control device to backup switching by the control program in the host processor is performed as follows. While online,
The control program in the host processor transfers the line take to the communication control device 2 via the channel interface 101, and also sends IO to the active machine at regular intervals.
They carry out what is called a patrol to check for any obstacles. When a fault is detected in the active machine through this IO patrol, the system console is notified of the faulty active machine number using the direct control interface 102, and is instructed to switch to the standby machine. Upon receiving this instruction, the system console issues a DISABCE instruction to the faulty active machine, and an ENABLE message to the standby machine, which is the configuration information of the communication control device corresponding to the active machine number to be switched. Signals instructing this are sent through the switching instructing ink□ faces 1o3, 1o, and a, respectively. At the same time, a switching control line 105 is sent to the line changeover switch 5 so that the switch with the active machine number to be switched is connected to the standby machine side.

The above series of operations completes the switching.

This conventional protection switching required special interfaces and hardware, namely the direct control interface 102 and the system console 7, to control the protection switching. For this reason, there was a problem in terms of system configuration, which led to cost reductions.

[Purpose of the invention]

An object of the present invention is to provide a backup switching control method that is inexpensive and has a simple configuration that does not require any special interface or hardware such as a direct control interface or system console used in the backup switching system of the prior art. It is in.

[Summary of the invention]

The features of the present invention are based on the problems of the prior art described above.

By providing a command related to backup switching control in the channel interface used for sending and receiving line data between the host processor and the communication control device, and decoding and executing this command in the backup communication control device, This eliminates the need for a system console or direct control interface that was required with conventional technology.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. This system consists of a host processor 1, a current communication control device 2. Spare communication control device 3゜Communication line interface 1
5. A line changeover switch that switches 06 to either the working side or the standby side. Then, in response to the preliminary switching control command from the host processor 1, the line is switched to the communication control device 2.

It consists of a standby switching addition mechanism 6 mounted on a standby communication control device that issues a switching command to the switch 5. A control signal 104 from the backup switching addition mechanism 6 to each communication control device is used to set each communication control device to ENABE or DISABL.
This is for instructing whether to select E or not. A channel interface 101 connects host processor 1 and communication control device 2.3. Usually it is used primarily for line data transfer. In the present invention, a command for backup switching control is newly provided as this channel command.

FIG. 3 is an example of this backup switching control command.

This command was designed to be able to instruct backup switching at the same time as instructing IPL. Instructing. In the case of the pattern (85)+e in the example of FIG. 3, it is instructed to back up the currently used first communication control device.

When performing backup switching, the backup machine communication control device recognizes the above-mentioned backup switching control command, and notifies the backup switching addition mechanism 6 that there is a switching instruction and the number of the active machine to be switched. The standby switching addition mechanism 6 controls the operation of the standby unit by ENAB.
It decodes the switching instruction given while switching to IJ, and sends a switching instruction 104 to the current communication control device and a switching instruction 105 to the line changeover switch.

In this system, the procedure from detection of a fault in the active communication control device to backup switching by the control program in the host processor is performed as follows. While online,
The control program in the four processors of the host computer communicates with the communication control device 2 through the channel interface 101,
In addition to transferring iJ data, data is sent to the current machine at regular intervals.
・Checking for the presence of failures, also known as IO patrol. When a fault in the working machine is detected by this IO patrol, it issues the channel command for the standby switching control to the standby communication control device 3, notifies the working machine number where the fault has occurred, and instructs switching to the standby machine. The backup communication control device 3 and the backup switching addition mechanism 6 installed therein receive this instruction and switch the DISA to the faulty active machine.
BLE instructions, and for the standby device, send configuration information of the communication control device corresponding to the active device number to be switched to ENAB.
A signal instructing to switch to LE is sent through the switching instruction interface 104. At the same time, the switching control line 10 is connected to the line changeover switch 5 so that the switch with the active machine number to be switched is connected to the standby machine side.
5 is sent. The above series of operations completes the switching.

The communication control device originally has basic control functions such as receiving channel commands, so even if a command for preliminary switching control is provided, it cannot be decoded.

The amount of hardware required for the backup switching addition mechanism to execute is small. Furthermore, since the control line for controlling the inside of the standby machine is not external, the cable for the switching control interface 103, which was necessary in the conventional technology, is no longer necessary.

As described above, according to this embodiment, it is possible to realize an automatic standby switching system that is inexpensive and has a simple configuration, eliminating the need for a system console or direct control interface control, which were necessary in the prior art.

In this embodiment, the case where there is one host processor and the channel interface is one channel is shown.
This method can be easily applied to the case of multiple hosts and multiple channels, and in this case, the number of instruction systems for instructing backup switching increases, which also has the effect of improving the reliability of backup switching instructions.

Note that in this embodiment, the switching control information is specified as a command pattern, but it is also possible to specify it in the transfer data as another embodiment.

〔Effect of the invention〕

According to the present invention, there are the following effects.

(1) There is no need to control the system console and direct control interface, which were required in the conventional automatic standby switching system.

Therefore, it becomes possible to configure an automatic standby switching system that is inexpensive and has a simple configuration.

(2) Channel interface commands) - Since basic control functions such as reception are originally held by the communication control device,
Decoding and executing backup switching control commands.

Very little hardware needs to be added for the line.

(3) By adding a standby switching control field to the control program load command to the communication control device as in the embodiment, the channel command Simultaneous processing of one issue is possible, and the time required for preliminary switching can be shortened.

(4) Since the control/program on the communication control device side required for backup switching can be loaded from the host side, flexibility regarding switching control is improved.

For example, the host can notify the backup machine of the configuration information of the active machine that is to be backed up, making it easier to respond to configuration changes.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a backup switching system according to the prior art, and FIG. 2 is a configuration diagram of a backup switching system that is an embodiment of the present invention.
FIG. 6 is an example of the format of the backup switching control command used in the present invention. 1 is the diagram shown. DESCRIPTION OF SYMBOLS 1... Host processor, 2... Current communication control device, 3... Backup communication control device, 4... System console, 5... Line changeover switch, 6... Backup switching addition mechanism, 7 ...Modem, 101...Channel interface signal, 102...
・Direct control interface signal, 103
...Switching instruction signal to backup communication control device, 104
...Switching instruction signal to the current communication control device, 105
...Switching instruction signal for line changeover switch, 110
6...Communication line. 2 l Figure 2 Mouth 15 Figure If'L / jElEC7 4,31:lEC7

Claims (1)

[Claims] Backup switching of a communication control device consisting of a host processor, a plurality of active communication control devices and standby communication control devices connected to the host processor through a channel interface, and a line changeover switch that switches the communication line connected to the communication control device between standby and active. In the system, set the command for standby switching control in the channel interface command.
The backup communication control device is equipped with a function that can decode this command and issue a switching command to the line changeover switch and the current communication control device. A backup switching control system characterized by issuing a switching command based on a channel command, decoding this with a backup communication control device, and transmitting the switching command.