JPS6113352A - Method for exclusively controlling shared file - Google Patents

Abstract

PURPOSE:To cope with long-time occupancy of a shared file when the shared file is already occupied so as to use the file efficiently, by counting the occupancy requesting number from others and, when the count number reaches a prescribed value, giving interrupting information to the occupying source. CONSTITUTION:A file 1 is controlled and exclusively managed by a file controlling section 2 composed mainly of a processor 3 and connected with host systems A-C which are the common users of the file 1 through a channel 4. The file control section 2 is provided with a counter which counts the occupancy requesting number accepted from other host systems while the shared file 1 is occupied and, when the count value of the counter reaches a prescribed value, performs an interruption to the occupying host system and informs the host system that the count value of the counter reaches the prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field> The present invention relates to data processing systems, and particularly to exclusive management control of files when a common large-capacity file is shared by multiple systems.

<Prior art and background> Normal large-scale data processing systems have a multi-system configuration in which multiple different systems occupy the same hardware while processing multiple data in parallel, and a common large-capacity file. There are many cases in which the system is operated in a shared configuration, and in such cases, a specific function or functional part within a specific device is occupied for a certain period of time by processing requested by a specific system, so each part is divided to avoid conflicts due to repeated requests. Exclusive control is required and put into practical use to manage the occupancy status of such devices.

In the conventional exclusive control, the exclusive control unit has registers for registering the occupancy status of a specific function or functional part to be managed, as many as the management units of the controlled object, and transfers information from a specific system to a specific controlled object. When receiving an occupancy request command indicating that a target is to be occupied, if the target is unoccupied, the request is accepted, registered, and possession is permitted, but if it is already occupied by another system, permission is not granted. Control has been carried out in which the response is returned to the system in question, causing the system to wait, and the occupation is maintained until a release command is received from the currently occupied system or a timeout is determined by the abnormality monitoring system.

Problems: However, with this type of control, there may be cases where there is a careless system user, a certain system malfunctions internally, or
If the process loops or hangs, the occupancy will be reset and an unspecified host system will continue to occupy the shared hardware that is managed under exclusive control, such as a specific volume of a large file, and other The problem is that the host system becomes unusable, which reduces the overall system efficiency. Moreover, with current control methods, although time is monitored, it is necessary to assume that execution programs (commonly known as jobs) require occupancy for quite a long time.For safety reasons, the timeout must be set to a fairly long time. During this time, the abnormality determination is delayed, and the status is lost when reset, and early detection of the abnormality is also the cause.
It is not easy to identify the A-occupying system, and the process tends to be delayed.

<Solution Means> In view of the above, the main purpose of the present invention is to provide a shared large-capacity file (
The exclusive control management unit of the file control device that exclusively controls the targets managed under exclusive control, such as files (hereinafter simply referred to as files), is assigned the current occupancy as usual for each management unit such as the volume that is the management target in the file under control. In addition to providing a current occupancy register for registering the system, there is also a reception register that temporarily accepts occupancy request commands, and an occupancy request count that increments based on the number of times occupancy request commands arrive, provided that the volume is already occupied. In addition to providing a counter for each management unit, there is also a means for monitoring the value of the above counter and comparing it with a preset designated value to see if it matches, and an interrupt to the currently occupied host system on condition of a match. The method is to add means for sending control information indicating that the counter has reached a specified value, and means for controlling these procedures.

<Operation> By adding such means to the conventional exclusive control, when the procedure control means receives an occupancy request command for a certain volume from a certain host system in the reception register, the system code of the received request source and the current Compare it with the system code in the occupancy register, and (if there is no already occupied system, register it as is and allow occupancy)) Return a permission response to the request source. Also resets the counter.

■Also, even if the currently occupied register is already registered, if the system codes match, a permission response is returned to the request source, but the state of the currently occupied register and the counter value are not changed. (2) If the current occupied register is already registered and the system codes do not match, a non-permission response is returned to the requesting system and the counter value is incremented by one. Of course, the contents of the current occupied register will not be changed. While continuing to manage the occupancy according to the state of the current occupancy register by performing response control such as If the counter matches the specified value or exceeds the specified value, the counter is registered in the current occupied register corresponding to the counter that has reached the specified value on the file control device side as a countermeasure when this condition is detected. The present invention is realized by performing procedural control such as interrupting an occupied host system and sending control information containing the fact that a specified value has been reached.

To make a slight correction, the host system that received the above control information will know that at least another host system is also requesting occupancy for the currently occupied volume. If necessary, you can check this to detect abnormalities early, or if necessary, you can query other host systems, or you can cyclically log a specified number of request sources accepted in the exclusive request reception register on the file control device side. By applying the means and procedure for identifying other host systems that have requested exclusive use, such as having them sent back along with the above control information, the source of the exclusive use request can be learned, and measures such as asking the operator whether or not to continue the job can be taken. If possible, countermeasures such as releasing the occupation and allowing the job of another host system to take precedence can be taken quickly.

<Embodiment> FIG. 1 is an explanatory diagram of one embodiment of the present invention, and is a diagram showing the main part of a newly added procedure in exclusive control, and is an explanatory diagram of the system configuration and data area in the memory 10. .

As shown in the figure, a shared file 1 is controlled and exclusively managed by a file control unit 2 mainly consisting of a control processor 3, and is connected to host systems A, B, and C, which are shared optical devices, via a channel 4. It is assumed that the middle part of file 1 is a crosspiece, and the IY l--first volume is used as a constituent unit, and exclusive management is performed on a volume-by-volume basis.

For this purpose, the file control unit 2 has a management function for exclusive control, and as a means of realizing this function, a current occupancy register is used to register occupancy for each volume IX to IGL that is subject to occupancy management. 6, , 6Y
~6α, a reception register 7X ~71 that temporarily accepts for processing when an occupancy request command is received for the volume, and a counter 8X ~71 that counts the number of occupancy requests received from other host systems during occupancy. 8
It is assumed that a corresponds to the volume, a register 9 for storing a specified number of cents is set in an area of the memory 10 of the file control section 2, and a control program is stored in the control memory 11. Under such a configuration, the processor 3 uses each volume exclusively in the state of the current occupancy register 6× to 6αtit III/, and when there is an occupancy request, the current occupancy register is registered from the reception register to the current occupancy register. The request is accepted and granted to the requesting host system via channel 4. It is assumed that the identification code of the requesting host system and the code specifying the target to be occupied, which are added to the occupancy request command, are included as data at least.

Next, if the reception register receives a request but the current occupation register is already occupied, compare the system code registered in the current occupation register with the system code of the request accepted by the reception register, and if they are the same, return a permission response. However, the management side maintains the current status, and if there is a mismatch, returns a non-permission response and increments the counter by 1, compares the counter value with the value in the specified value register, and if it reaches the specified value, it is registered and currently occupied. It refers to the system code of the currently occupied register, interrupts the host system, and reports that the counter value has exceeded the specified value. At this time, if necessary, the request for the reception register may be returned together with the code of the original host system as additional information.

<Effects> By performing such control, the occupied host system is competing with other host systems, as well as 1. Since it is possible to consider the possibility that the device may have been occupied for a considerable period of time and take corresponding measures, this can be useful for early detection of abnormalities and efficient operation of the entire system. By logging such competition information, it is possible to obtain useful reference materials for checking the system operation mode and equalizing load sharing.

[Brief explanation of the drawing]

1, 2, and 3 are explanatory diagrams of an embodiment of the present invention. FIG. 1 is a flowchart for explaining the functional procedure of the invention, and FIG. 2 is a system configuration. FIG. 3 is an explanatory diagram of the data area configuration. In the figure, 1 is a file, 5 is a distribution channel, 2 is a file control device, 3 is a processor, 4 is a channel, 10 is a main memory, and 11 is a control memory. B, C, indicate host systems. Further, in the main memory configuration, 68 to 0 are current occupied registers, 7 and 7Q are reception registers, and 8x to 8α are counters, and each corresponds to a suffix and corresponds to volumes IX to 1α in the isle 1. It is also a generic term without a suffix. Further, 9 indicates a register. (Tsuma'1cJ) Arithmetic 1 diagram

Claims (1)

[Claims] In exclusive control of a shared file in a multi-configuration data processing system that has a file shared by multiple host systems and a control device for the file, each volume within the above file is divided into management units for exclusive management. In addition to having a current occupancy register for registering the currently occupied host system, an acceptance register for accepting occupancy requests, and means for executing corresponding response procedures, an occupancy request counter corresponding to each volume, and at least one designated value register; It has a procedure for monitoring the value of the occupied request counter, and when a certain current occupied register receives an exclusive request from another host system during registration, in addition to returning a disallowed response to the source of the request, the above-mentioned occupied request 1. A method for exclusive control of a shared file, characterized in that a counter is incremented, and when the value of the occupied request counter reaches a specified value or more, an interrupt is made to the current occupier and information notification is performed.