JPH05128074A - Network system - Google Patents

Abstract

PURPOSE:To speed up an access to a network file and to prevent a large-scale system from being degraded in its performance. CONSTITUTION:In a server/client system, a file cache area 8A for temporarily storing the copy of a part of data stored in a hard disk 4 is formed in a main storage device 8 in server device 1. A CPU 7 in the server 1 transfers the copy of a part of a file existing in the disk 4 to the cache 8A in accordance with a file access, transfers only a block including a part necessary for operation of the client device 2 in accordance with the contents of an operation instruction outputted from the client device 2, and at the time of ending the operation, re-transfers only the block used for the operation to the file cache area 8A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system, and more particularly, to a server device which is an information processing device equipped with a file device and a printer device, and an information device connected to the server device by a network cable. The present invention relates to a network system called a server / client system including a certain client device.

[0002]

2. Description of the Related Art Conventionally, in a server / client system, an operator who uses a client device can freely use a file device or a printer device provided in the server device as if the device itself is provided. , Adopted in many places. In this conventional server / client system, when the file server function or print server function is used, all the target files are once transferred to the client device side, and then again when it is necessary to save or print the files. The file was transferred to the server device side.

[0003]

In the above-mentioned conventional network system, when a file existing in the file device on the server device side is called from the client device, or the contents of the file on the client device are read by the server device. When printing with the printer device on the server side or when re-storing the file on the client device into the file device on the server device side, the entire target file is transferred via the network cable each time. The number of client devices is increased because the entire file is transferred even if the file is changed, file access takes time due to the file transfer time, and network traffic increases due to frequent file transfer. Access performance deteriorates immediately,
There was an inconvenience.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the disadvantages of the prior art, and to connect the server device and the client device via a network cable even when the number of client devices is increased and the system is enlarged. Another object of the present invention is to provide a network system capable of preventing the performance degradation of the file access.

[0005]

A network system according to the present invention comprises a server device having a file device and a printer device, and a client device connected to the server device by a network cable. Further, a file cache area for temporarily holding a copy of part of the data stored in the file device is provided on the main storage device of the server device, and the central processing unit of the server device stores the file A function to transfer a copy of part of the file that exists in the file device to the file cache area in response to a call, and to the client device side only the block containing the part necessary for the operation according to the operation instruction content from the client device side And a function of re-transferring only the block that is the target of the operation to the file cache area upon completion of the operation. With such a configuration, the above-described object is to be achieved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows the configuration of an embodiment of the present invention. The network system of the embodiment shown in FIG. 1 has a hard disk device (hereinafter, abbreviated as "hard disk" in this embodiment) 4 as a file device.
A server device (hereinafter abbreviated as “server” in the present embodiment) 1 including a printer device (hereinafter abbreviated as “printer” in the present embodiment) 3 and a server 1 and a network. A client device connected by a cable 6 (hereinafter, abbreviated as "client" in this embodiment).
2 and.

Of these, the server 1 is configured to include a central processing unit (hereinafter referred to as "CPU" in this embodiment) 7 and a main memory 8, and in fact, a relatively large computer. (Information processing device). And
On the main storage device 8 of this server 1, a hard disk 4
A file cache area (hereinafter, abbreviated as "file cache" in the present embodiment) 8A for temporarily holding a copy of a part of the data stored in the file cache 8A. A file busy flag area 8B indicating whether or not data is in use is provided (see FIG. 2).

The client 2 has the same CP as the server 1.
The U9 and the main memory 10 are included, but this is actually a relatively small computer. A console 5, which is a terminal device operated by an operator, is connected to the client 2. Although only one console is shown here, a plurality of consoles are actually connected. Then, an operator who operates the console 5 connected to each client 2 can freely use the hard disk 4 and the printer 3 provided in the server 1 from a remote place via his or her own device (client). There is.

Then, the CPU 7 of the server 1 sends a file read request from the client 2 when a copy of the file exists in the file cache 8A, and when it does not exist, the file cache 8A stores the file. The first function of reading at least a part of the file and notifying the client 2 of the completion of the file transfer, and when the client 2 gives an instruction for an operation such as editing the file, the block including the target portion of the operation is If the file cache 8A exists, the second function of directly fetching the file cache 8A from the hard disk 4 and then transferring only that block to the main storage device 10 of the client 2 if the file cache 8A does not exist, Set a busy flag ("1")
The third function and the main storage device 10 of the client 2 when there is a file write request from the client 2.
A fourth function of transferring the upper block to the file cache 8A, and when the client 2 instructs to save the file again, the data in the file cache 8A is restored to the hard disk 4 and the file busy flag is cleared ( The fifth function (set to “0”) and the block in the main storage device 10 of the client 2 when the file in-use flag is set when the file is requested to be printed from the client 2 by the file cache 8A.
If the file in-use flag is not set after the transfer to the printer, the sixth function for immediately outputting the data in the file cache 8A to the printer 3 and the access from another process to the file for which the file in-use flag is set It has a seventh function that prohibits here,
The various functions of the CPU 7 are actually realized by control software.

Next, the operation of this embodiment constructed as described above will be described with reference to FIG. Here, FIG.
FIG. 3 is a diagram showing a data existence state in the present embodiment, and is a file “ABC” or one of the files existing in the main memory 8 in the hard disk 4 and the server 1 and the main memory 10 in the client 2 of FIG. A copy of the department is shown. It should be noted that, as described above, the main storage device 8 also has the file busy flag area 8B in addition to the file cache 8A, and a part of the file busy flag area 8B is also shown as the busy flag of the file "ABC". ..

As a premise, as shown in FIG.
It is assumed that a file "ABC" exists on the hard disk 4 connected to the file "ABC", and this file "ABC" consists of five blocks, block-1 to block-5. Here, it is assumed that the operator wants to print a part (the part existing in block-4) of the file "ABC" after editing from the console 5 connected to the client 2. Further, the file cache 8A on the main storage device 8 of the server 1 is limited in capacity, so that it is possible to accommodate a maximum of 3 blocks per file.

For editing, the operator first issues an instruction to call the file "ABC" from the hard disk 4. In this embodiment, the instruction causes the CPU 7 of the server 1 to operate.
Then, first, the file "ABC" from the hard disk 4 is stored in the file cache 8 on the main storage device 8 of the server 1.
Transfer to A. However, due to the capacity limitation of the file cache 8A, block-1, block-3, block-
Transfer only 3 blocks of 4. Then, the CPU 7 issues a file call completion notification to the client 2 when the transfer to the file cache 8A is completed. As a result, the client 2
It seems that the file "ABC" has been transferred to the main storage device 10 of. So the operator enters the editing work,
Assume that the user has instructed to edit the portion existing in block-4 of the file "ABC". Then, for the actual editing work, the target data is the main storage device 10 of the client 2.
Since it needs to be present and is sufficient, the CPU 7 transfers only the block-4 including the target data portion to the client 2 side. In this case, when the block-4 does not exist in the file cache 8A on the main storage device 8, the CPU 7 first determines the hard disk 4
After transferring the corresponding block from the file cache to the file cache 8A,
Transfer to the client 2 side. Then, in the CPU 7,
When the transfer to the client 2 side is completed, the server 1
The in-use flag of the file "ABC" on the main storage device 8 is set to "1". Data transfer via the network cable 6 for the file "ABC" only occurs at this time. In this case, since the file "ABC" busy flag is set, the CPU
In No. 7, access to the file "ABC" from other processes is prohibited. This prevents the occurrence of data inconsistency. FIG. 2 shows the state at this time.

Next, the operator performs the necessary editing work on the data in the block-4 of the file "ABC". At this time, in the same way as in the conventional case, on the main storage device 10 of the client 2 itself. Editing work is performed locally (without passing through the network cable 6). Therefore, at the time when this editing is performed, the contents of block-4 on the main storage device 10 of the client 2 and the contents of block-4 on the main storage device 8 of the server 1 are different. However, when a file write request is issued from the client 2 thereafter, the CPU 7 transfers the block -4 on the main storage device 10 of the client 2 to the file cache 8A. The result of the editing work done on the 2nd side is reflected and becomes correct.

Instead of the file write request from the client 2, the file "AB" is sent from the operator.
When the print instruction of the contents of "C" is issued, the CPU 7 sets the file "ABC" busy flag.
Block-4 on main memory 10 of client 2
Is transferred to the file cache 8A in the main memory 8 of the server 2. At this point, similarly, the contents of the file cache 8A are correct as the result of the editing work performed on the client 2 side is reflected. Then, for the printer 3, the file "ABC" on the hard disk 4
Is output, the CPU 7 outputs the contents of the file cache 8A for the blocks in the file cache 8A at that time, that is, block-1, block-3, and block-4. However, if the file print instruction is
When the file busy flag is not set, the CPU 7 immediately outputs the data in the file cache 8A to the printer 3.

In addition, the file "ABC" from the operator
When an instruction is given to save the file again, the CPU 7 writes the contents of the file cache 8A to the hard disk 4
At the same time, the busy flag of the file "ABC" is cleared (set to "0").

As described above, according to this embodiment,
Unlike the conventional network system (server / client system), when a file existing in the hard disk 4 on the server 1 side is called from the client 2,
When printing a file on the main storage device 10 of the client 2 by the printer 3 on the server 1 side or when re-storing the file on the main storage device 10 of the client 2 on the hard disk 4 on the server 1 side, the network cable 6 The data transfer via the file is not the entire target file but only the necessary blocks, and the number of times of transfer is minimum. In the above description, the transfer of block-4 is once from the server 1 to the client 2 and from the client 2 to the server 1. 1 in total
Since the number of times is only one, file access can be speeded up, and increase in network traffic can be suppressed to a minimum, so that a large-scale system with relatively good access performance can be constructed.

[0018]

Since the present invention is constructed and functions as described above, according to the present invention, the functions of the central processing unit of the server device allow the data to be transferred between the server device and the client device via a network cable. It is possible to significantly reduce the number of files to be transferred and the number of times of transfer itself, so that it is possible to speed up file access via a network cable and to suppress an increase in network traffic to a minimum. It is possible to prevent a sharp decline in access performance even when the number of devices is large, and to provide an unprecedented excellent network system capable of constructing a large-scale system with relatively good access performance. it can.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the embodiment of FIG.

[Explanation of symbols]

 1 Server Device 2 Client Device 3 Printer Device 4 Hard Disk Device as File Device 6 Network Cable 7 Central Processing Unit of Server Device 8 Main Storage Device of Server Device 8A File Cache Area 8B File Busy Flag Area 10 Main Memory of Client Device apparatus

Claims (3)

[Claims] 1. A network system comprising a server device having a file device and a printer device, and a client device connected to the server device by a network cable. A file cache area for temporarily holding a copy of part of the data stored in the file device is provided, and the central processing unit of the server device,
Only the function of transferring a copy of a part of the file existing in the file device to the file cache area in response to a file call, and only the block including the part necessary for the operation according to the operation instruction content from the client device side A network system having a function of transferring to the client device side and a function of re-transferring only a block which is the target of the operation to the file cache area upon completion of the operation. 2. A network system comprising a server device having a file device and a printer device, and a client device connected to the server device by a network cable. A file cache area for temporarily holding a copy of part of the data stored in the file device, and a file busy flag area indicating whether or not the data held in the file cache area is in use. Is provided, the central processing unit of the server device, when a file read request is made from the client device, if a copy of the file exists in the file cache area, at that time, otherwise, the file cache After loading at least part of that file into the area, The function of notifying the client device of the completion of the file transfer, and when the client device gives an instruction for an operation such as editing of the file, if the block including the target portion of the operation is in the file cache area, it is directly If not, a function of fetching from the file device to the file cache area and then transferring only that block to the main storage device of the client device; a function of setting a busy flag of the file at the same time when the transfer is completed; When a file write request is issued from the client device, the function of transferring a block in the main storage device of the client device to the file cache area, and when the client device instructs to save the file again, the data in the file cache area is When re-stored in the file device In addition, the function of clearing the file in-use flag and the block in the main storage device of the client device when the file in-use flag is set when a file print request is made from the client device is used as the file cache area. And a function of outputting the data in the file cache area to the printer device immediately after the file is in-use flag is not set. 3. The central processing unit of the server device,
3. The network system according to claim 2, further comprising a function of prohibiting access from another process to the file for which the file busy flag is set.