JPH037965B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a recovery processing method in the event of a momentary power outage in a data processing device, and in particular a method for saving information being processed at the time of a momentary power outage and performing recovery processing when the power is restored. It also relates to a recovery processing method that takes measures to prevent malfunctions for unrecoverable items.

[Technology background]

Conventional data processing equipment generally has a system that can maintain the supply voltage within a pre-specified tolerance value in the event of an extremely short-term interruption of power input, ie, a power outage of several hundred milliseconds or less. Power supply is in use. Therefore, if a power outage continues beyond the specified time, the supply voltage will drop rapidly, processing functions will stop, data in registers and memory will be destroyed or lost, and then the power will be restored. However, it was no longer possible to continue with the process.

For this reason, in the past, power outages were detected using software and the system was brought down unconditionally regardless of the status of the data at the time of the power outage.As a result, when a power outage occurred, the process had to be restarted from the beginning in all cases. It was hot.

[Object and structure of the invention]

An object of the present invention is to eliminate the need for reprocessing for recoverable items without bringing down the entire system when a momentary power outage occurs in a data processing device, thereby reducing the time and effort required for reprocessing. The purpose is to reduce processing time, and for this purpose, the configuration is as follows.
a power supply device capable of maintaining a supply voltage within an allowable value in response to a momentary power input interruption within a predetermined time;
In a data processing device equipped with a storage device that is non-volatile for at least a longer period of time than the predetermined time, a means for detecting a momentary power input interruption and its recovery, and a means for detecting a momentary power input interruption and recovery thereof, Means for saving information predicted to be destroyed due to a momentary power interruption in the processing device to the non-volatile storage device, and the saved information when recovery from the momentary power input interruption is detected. and a means for restoring the input/output device that was in the process of accessing at the time of the instantaneous power input interruption, and the means for restoring the input/output device that was in the process of accessing at the time of the instantaneous power input interruption. , generates a pseudo error for the input/output request that was being accessed at the time of the momentary power outage, prohibits access to the input/output device, initializes the input/output device, and removes the input/output request that was previously prohibited from accessing. The system performs retry processing, and is characterized by interrupting the process being executed at the time of a momentary power input interruption, and allowing the previously interrupted process to continue when the power input interruption is restored.

[Embodiments of the invention]

The details of the present invention will be explained below with reference to Examples.

FIG. 1 is an overall configuration diagram of a data processing device according to an embodiment of the present invention, FIG. 2 is a detailed view of its main parts, and FIG. 3 is a schematic diagram of its operation timing.

In FIG. 1, 1 is a power supply device, 2 is a power input instantaneous interruption/recovery detection section, 3 is a CPU, 4 is a instantaneous power interruption recovery processing section, 5 is a key storage device, 6 is a main storage device,
Reference numeral 7 indicates a save area, 8 a backup battery, 9 an input/output control device, 10 and 11 input/output devices, 12 a power input, 13 a supply voltage, and 14 an interrupt signal.

The power supply device 1 is capable of maintaining the supply voltage 13 for a predetermined period of time, for example, several hundreds of milliseconds, which is sufficient for evacuation processing even if the power supply input 12 is momentarily interrupted. The power input instantaneous interruption/recovery detection section 2 is
Momentary interruption and recovery of the power input 12 are detected, and an interrupt signal 14 is generated to the CPU 3 in each case.

As one of its functions, the CPU 3 has a power supply interruption recovery processing section 4, which accepts an interrupt signal from the power supply input interruption/recovery detection section 2, and when a momentary power input interruption occurs, interrupts the job processing being executed and causes the CPU 3 to Information whose contents cannot be guaranteed in the event of a momentary power outage, such as information in various registers (not shown) or memory protection key information in the key storage device 5, is stored in the save area 7 of the main storage device 6. Then, when the power input momentary power interruption is recovered, the information in the save area 7 is restored to the key storage device 5 of the original register, and
Performs recovery processing for the input/output device, which will be described later. In this way, the environment for continuing the previously interrupted job processing is prepared and the processing is resumed.

The main storage device 6 is maintained at an operating voltage by a backup battery 8 for a predetermined period of time, for example, several tens of minutes, after the power is turned off, and during that time, the contents of the storage area including the save area 7 are volatilized (Vclatile). Hold it without any trouble. Therefore, if the stopped state of power input is restored within this predetermined time, the above-described recovery process becomes possible.

FIG. 2 shows details of the instantaneous power input interruption/recovery detection section 2 and instantaneous power interruption recovery processing section 4 shown in FIG. 21 to 25 are hardware mechanisms,
21 is a power failure detection mechanism that detects the occurrence of a momentary power interruption in the power input; 22 is a power failure interrupt generation mechanism; 23 is a timer mechanism that indicates the time during which nonvolatility of the main storage device 6 is guaranteed; and 24 is a device that detects recovery from a momentary interruption. A power failure detection mechanism 25 represents a power failure interrupt generation mechanism configured with AND logic. Further, 41 to 49 are software-based processing functions, 41 is a power failure interrupt detection process, 42 is a job interruption and register saving process, 43 is a power failure interrupt detection process, 44 is a register restoration process, and 45 is an input process. This is an output device recovery process, and 46 to 48 are detailed processes of the process 45, 46 is an input/output device initialization process, 47 is an input/output request error simulation process, and 48 is an input/output request retry process. , and 49 represents restarting the job after completion of the recovery process. The figures also show the flow of processing.

The timer mechanism 23 is activated and turned ON when the power failure detection mechanism 21 detects the occurrence of a power failure, and is turned OFF after a predetermined period of time has elapsed. This time is set shorter than the period during which the non-volatility of the main memory device 6 is guaranteed, that is, the life time of the backup battery 8, as described above.

The power failure interrupt generation mechanism 25 is a timer mechanism 23
The power recovery detection mechanism 24 is activated within the period when the output level of
Only when detecting power restoration, a power restoration interrupt signal is generated to perform instantaneous power failure recovery processing.

In the input/output device recovery processing 45, post-input/output device reset processing is performed for input/output devices that are at risk of undergoing hardware changes such as buffer clearing or microprogram initialization due to a momentary power interruption. Therefore, the input/output request error simulation process 47 generates a pseudo error for the input/output request that was being accessed at the time of the momentary interruption, and prohibits access to such input/output devices. Then, the instantaneous interruption is notified to device management programs such as VTAM (communication access method) and resource management.
Upon receiving the instantaneous interruption notification, the device management program releases the access prohibition and executes input/output device initialization processing 46 as post-processing. Incidentally, until this post-processing is performed, a pseudo error is generated for access requests requested from other general programs to prevent malfunctions.

When the input/output device initialization process 46 is completed, the input/output request for which the access prohibition was previously lifted is retried based on an error by the input/output request retry process 48.

Next, the input/output device recovery process 45 will be explained in more detail.

Generally, if a power outage occurs after a device is requested to execute an I/O command, the response to the previously requested I/O command will be lost, and depending on the device type, the device may There are some things that return the state to the initial state (for example, in line printers, control information for setting line spacing, etc., in display devices, character patterns, etc., in line control devices, information such as connection status with other systems/terminals, etc.) ).

Therefore, if the system does not intervene when the power is turned off, the requested input/output command (request) will result in an unresponsive error (timeout failure), and if the same device is subsequently used, it will be in an uninitialized state.
If an error occurs due to a malfunction or non-initialization, the job that is requesting the request will end abnormally, and the job started after that will also end abnormally. To recover from this, it is necessary to take measures such as activating initialization processing for each device through operator intervention.

In the input/output device recovery process 45 of the present invention,
The following mechanism is provided to prevent the above abnormal situation from becoming apparent.

First, each job that was running in the system at the time the power failure interrupt occurred is interrupted. this is,
This means that the various control tables for controlling jobs in the system are saved as they are at that time. In this state, when a power recovery interrupt occurs subsequently, the input/output device recovery process 45 is called as an extension of the interrupt process. In this process, the control tables that control each job (especially the control tables that control input/output commands) are inspected, and the devices that were requesting input/output commands (accessing) at the time of the power outage interrupt are inspected, and even if the system is not in use, the Devices that require initialization processing (displayed in advance in the control table within the system) are selected based on the process).

Initialization processing 46 prepared for each device type
Now, the line spacing control information as described above is reset to the line printer, and the necessary character patterns are loaded to the terminal control device. This will be re-initialized with the various information that was set just before, based on the information in the control table saved at the time of the power failure interruption.

When the initialization process 46 for each device type is completed, the error simulation process 47 immediately simulates the request that was being accessed at the time of the power outage interrupt (input/output command request). A momentary power interruption error state is created (error simulation), control is passed to an error recovery processing routine that is standard equipment in the system for each type of device, and retry processing 48 of the input/output request is performed. Note that even if a new access request occurs to the device that is in the process of initializing,
The request is temporarily placed in the instantaneous power failure error state as described above, and is made to wait until the initialization process is completed.

As shown above, if the system does not intervene in response to a power outage, jobs will continue to terminate abnormally unless the operator starts initialization processing for each device. By automatically starting the system process (input/output device recovery process) triggered by power restoration, the recovery process can be completed without each job or operator being aware of the power outage.

In this way, the recovery process can be executed at the time of a momentary power interruption, and the job can be restarted 49, without the need for the general program to be aware of the instantaneous power interruption.

In the operation timing diagram in Figure 3, a is power input, b is supply voltage, c is job processing, d is power failure detection signal, e is information saving processing, f is timer operation, g is power recovery detection signal, and h is Evacuation information restoration processing,
i represents input/output device recovery processing, and the illustrated timing example is when the timer is activated due to power failure detection.
This figure shows a case where power restoration detection is performed after turning ON but before turning OFF.

[Effects of the Invention] As described above, according to the present invention, it is possible to perform recovery processing in the event of a power outage and continue system operation without making a general business processing program aware of the power outage or power restoration. Therefore, the burden on users or operators can be significantly reduced.
Furthermore, erroneous processing that is likely to occur during recovery processing can be suppressed, and the efficiency and reliability of the system can be improved.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a device according to an embodiment of the present invention;
FIG. 2 is a detailed view of the main part, and FIG. 3 is an operation timing diagram. In the figure, 1 is a power supply device, 2 is a power input instantaneous interruption/recovery detection section, 3 is a CPU, 4 is an instantaneous power interruption recovery processing section,
5 is a key storage device, 6 is a main storage device, 7 is a save area, 8 is a backup battery, 9 is an input/output control device, 10 and 11 are input/output devices, 12 is a power input,
13 indicates a supply voltage, and 14 indicates an interrupt signal.

Claims (1)

[Scope of Claims] 1. A power supply device capable of maintaining a supply voltage within a permissible value in response to instantaneous interruption of power input within a predetermined time period, and a power supply device that is non-volatile for at least a longer period of time than the predetermined time period. In a data processing device equipped with a storage device, a means for detecting a momentary power input interruption and its recovery, and a means for detecting a momentary power interruption in the data processing device that is predicted to be destroyed by the instantaneous power interruption in the data processing device when the instantaneous power input interruption is detected. means for saving the information stored in the non-volatile storage device into the non-volatile storage device; means for restoring the saved information when recovery from the instantaneous power input interruption is detected; The means for restoring the input/output device that was in the process of accessing at the time of the instantaneous power input interruption is configured to restore the input/output device that was in the process of accessing at the time of the instantaneous power input interruption. This function generates a pseudo error, prohibits access to the input/output device, initializes the input/output device, and retries the input/output request for which access was previously prohibited. A power supply interruption recovery processing method characterized by interrupting a process being executed and allowing the previously interrupted process to be continued upon recovery from the instantaneous power input interruption.