JPH0964897A - Network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent transfer processing of the entire system from being delayed due to a delay in one transfer processing in the network system in which a network adopting the line survival system is used to transfer data requiring real time processing. SOLUTION: A server machine 1 is provided with a request content confirmation means 2 discriminating a content of a read request from a client machine 5, a data transfer control means 3 controlling transfer of data requested by a read request to a network 4. When data on request are moving image data, the request content confirmation means 2 sets a termination period of data transfer processing. When the processing time of transferring data on request from a disk device 15 exceeds a termination period, the data transfer control means 3 interrupts transfer processing and starts transfer processing with respect to other read request.

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, using a network of contention system,
The present invention relates to a network system that transfers data that requires real-time processing.

[0002]

2. Description of the Related Art A network for contention system such as Ethernet is widely used in offices and the like because it can be constructed easily and inexpensively. In a network system using this type of network, one of a plurality of machines connected by the network occupies the network and transfers data,
After the transfer is complete, another method is to release the network to another machine.

In a network system, moving image data and audio data may be transferred. However, since the moving image data and audio data are processed in real time at the time of reproduction, the network aims to reproduce these data. When transferring with, it is necessary to transfer in time for the reproduction processing. In addition, since moving image data in particular has a huge amount of data, it takes a long time to transfer the moving image data.
Therefore, in a network system that transfers moving image data, a time division network is generally used. In this network system, a line use period is assigned to each machine in advance, and the moving image data is divided and transferred during the use period. Further, since the second transfer is started before the reproduction processing of the moving picture data sent by the first transfer is completed, each machine can naturally reproduce the moving picture without interruption.

On the other hand, there has been proposed a system in which the time division method is applied to the network of the above-mentioned contention system. In this system, a plurality of client machines directly operated by users and a server machine such as a file server are connected by a network in a contention system so that video data can be transferred from the server machine to the plurality of client machines. Is configured. In addition, each client machine is set with an end deadline for limiting the network usage time, which allows the amount of moving image data transferred by one access to be transferred within the end deadline. Limited in amount. In FIG. 2 (a),
The following shows how video data is transferred in this system.
In the figure, the horizontal axis is indicated by time and the end deadline is indicated by vertical dotted lines. As shown in the figure, when the data is transferred to each client without delay, each client can naturally reproduce the moving image without interruption due to the divided moving image data. Further, in this system, when the transfer process for one client is completed, the process for the next client is immediately started, so that the line utilization efficiency is good.

[0005]

The problems of the above network systems will be described below.

First, in the network system of the contention system using the end deadline, if a delay occurs in the read processing for one client, the delay causes the subsequent read processing for all clients to be delayed. FIG. 2B shows the state of this delay. A shaded portion 8 in the drawing indicates the time of the processing performed after the end deadline, that is, the delay in the start of the processing for the next client. In the client where the start of the process is delayed, the moving image that is being played back is abnormal because the moving image data does not arrive in time. That is,
Since the processing for the client 1 is performed beyond the end deadline, the processing for the clients 2 and 3 also exceeds the end deadline, and as a result, an abnormality such as stopping the moving image is generated on all clients. To do.

Further, in the above time-division type network system, even if the processing for a certain client ends early, another processing cannot be performed, so that the utilization efficiency of the line is poor. In particular, this is not suitable when text data is transferred, where the processing time for one read request is relatively short. FIG. 2C shows how data is transferred in this system. The mesh part 9 in the figure is
The time when no processing is performed is shown.

As one of the techniques for solving the above problem, there has been proposed a system (Japanese Patent Laid-Open No. 3-270432) for connecting a network of a contention system and a network of a time division system to all clients. . In this system, a network of a contention system is used for transferring text data and the like, and a time division network is used for transferring data such as moving image data that requires real-time processing. However, in this system, it is necessary to install two networks side by side, which causes a new problem that the system construction becomes troublesome and the cost becomes high.

Therefore, the present invention prevents a delay in the transfer processing of the entire system due to the delay of one transfer processing in a network system that transfers data requiring real-time processing using a network of the contention system. To aim.

Another object of the present invention is to allow the reproduction processing of the data to be completed within the original processing time even when the transfer processing of the data requiring the real-time processing is delayed.

[0011]

In order to achieve the above object, the present invention provides a server device, a plurality of terminal devices for outputting a data read request to the server device, the server device and the terminal device. The server device is configured by a network for contention system to be connected, the server device stores data including data requiring real-time processing, and data corresponding to the read request received from the storage device by the terminal. A network system having means for transferring to a device, wherein the server device responds to the read request according to a determination means for determining the content of the read request from the terminal device and a determination result of the determination means. A means for setting an end deadline of the data transfer process, and when the transfer process is performed after the end deadline, Interrupting the transfer process, or, characterized in that a transfer limiting means for aborting.

[0012] Further, the server device terminates the transfer process when the transfer process is performed over an end deadline, and the data following the data not transferred due to the abort of the transfer process is transferred to the terminal device. It is characterized in that it is transferred without a read request from the.

[0013]

According to the above configuration, the end time limit of the transfer process of the data corresponding to the read request is set according to the content of the read request from the terminal device, and the transfer process is performed beyond the end time limit. In that case, the transfer process is interrupted or aborted. Therefore, the transfer processing time of the server device for each terminal device is suppressed to a desired length, and therefore, the delay of one transfer processing does not affect other transfer processing. Furthermore, when one transfer process is completed or interrupted, the next transfer process is immediately started, so that the transfer efficiency is higher than that of the time division network system.

When the transfer processing is aborted, the data following the data that was not transferred due to the abortion is transferred in the next transfer processing, so that the terminal device desires the reproduction processing of the transferred data. Can be done in time.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENT A network system according to an embodiment of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 is a diagram showing the configuration of a network system according to a first embodiment of the present invention. The network system shown in the figure comprises a server machine 1, client machines 5, 6, ... And a network cable 4 connecting the server machine 1 and the client machines 5, 6 ,. Here, the server machine 1 is, for example, a file server, and is commonly accessed by the client machines 5, 6, .... The client machines 5, 6 ... Are N terminals directly operated by the user.

The server machine 1 shown in the figure includes an operating system 1 and a network device 11.
A network device control means 12 for controlling the network device 11, a network protocol control means 13 for providing a network protocol such as TCP / IP, a network service control means 14 for providing a network service, and a disk such as a hard disk. The device 15, the disk device control means 16 for controlling the reading and writing of data with respect to the disk device 15, and the physical position of various data stored in the disk device 15 and managing the disk device. Disk access control means 17 for controlling access to the disk 15, request content confirmation means 2 for setting an end deadline according to the content of the data read request sent from the client machines 5, 6, ... 15
The data transfer control means 3 controls the transfer of the data read from the device according to the end deadline.

FIG. 5 shows a configuration example of the request content confirmation means 2 and the data transfer control means 3 described above. The request content confirmation unit 2 shown in the figure is a request content determination unit 21 that determines whether or not the read request from the client is for data that requires real-time processing, and the read request requires real-time processing based on the determination result. When it is for data, a request time confirmation means 22 for obtaining an end deadline, and an end deadline storage means 2 for storing the obtained end deadline.
And 3. Here, the end deadline is for limiting the time of one read process so that the read process is divided and performed on data that requires real-time processing.

On the other hand, the data transfer control means 3 shown in FIG.
Before the data read from the disk device 15 is transferred, the end deadline confirmation is performed to determine whether or not the time required for the read processing exceeds the end deadline stored in the end deadline storage means 23. Means 31 and end deadline confirmation means 3
According to the judgment result of 1, the transfer data generating means 32 generates the data to be transferred.

FIG. 6 shows an example of the structure of the disk device 15 described above. As shown in the figure, the disk device 15 includes a disk device A 151 (disk number #A), a disk device B 152 (disk number #B), and a disk device C 15.
3 (disk number #C). Here, in the disk device B152 and the disk device C153, data that requires real-time processing such as moving image data is stored.
The disk device A 151 stores data such as text data that does not require real-time processing.

All the signals transferred via the network cable 4 have the packet format based on the network protocol. The packet includes a plurality of pieces of information. For example, the packet signal sent from each client to the server and indicating the read request includes the ID number indicating the client of the transmission source and the ID number designating the server 1 of the transmission destination. , Information for instructing execution of data read processing, information for specifying data to be read (disk number, file name, data amount) and the like.

Next, the operation of the network system described above will be described.

Here, the disk device B15 of the server 1
2 (FIG. 4), a read request for the moving image data stored under the file name “MOVE” is issued from the client machine A5, and a read request for the text data stored in the disk device A151 is issued from the client machine B6. The case of being issued will be described. In this system, moving image data is transferred and reproduced based on the MPEG1 standard (described later), the client machine A5 issues a moving image data read request in units of 64 kB (kilobytes), and the server machine 1 executes once. In response to the read request, data transfer is performed 64 times in units of 1 kB. The state of data transfer at this time is shown in FIGS.

From the client machine A5 shown in FIG.
When a packet signal indicating a data read request is sent, first, the network device 11 of the server machine 1 is sent.
Receives this packet signal (mark 20 in FIG. 5).
This reception result is the network protocol control means 13
Sent to, where it is broken down into data for each piece of information. Then, the request content discriminating means 21 (FIG. 3) of the request content confirming means 2 examines the content of each data to determine that this packet signal is a read request, and that the requested data requires real-time processing. Is determined. The data type is specified by a table (not shown) in which the correspondence between the disk number and the data type is set.
Is searched by the information indicating the disk number (#B in this case). The request time confirming unit 22 obtains the end deadline of the reading process in accordance with the determination result of the request content determining unit 21, stores the result in the end deadline storage unit 23, and further reports that the end deadline is set. The transfer deadline confirmation means 31 of the transfer control means 3 is notified.

The operating system 10 receives the above data for each information via the network service control means 14, and according to the received data, the disk access control means 17 reads out the data of the file "MOVE" by 64 kB in units of 1 kB. Make a request to. As a result, under the control of the disk access control means 17 and the disk device control means 16, data from the file “MOVE” stored in the disk device 15 is saved as 1
It is read in units of kB. Then, the read data is transferred in the reverse order of the above, that is, in the order of the disk access control means 17, the operating system 10, the network service control means 14, and the data transfer control means 3.

The end time limit confirming means 31 (FIG. 3) of the data transfer control means 3 is instructed by the request content confirming means 2 that the reading process has the end time limit, and thus the transferred data is transferred by 1 kB. Each time, it determines whether or not the current processing time has passed the end deadline stored in the end deadline storage means 23 (mark 30 in FIG. 5). Then, the end deadline confirmation means 31 gives an instruction to the transfer data generation means 32 to transfer the fetched data when the processing time has not passed the end deadline. The data thus transferred is sent to the network protocol control means 13 and further sent to the client machine 5 via the frame network device control means 12, the network device 11, and the network cable 4. Then, the above-mentioned confirmation of the processing time and the data transfer in units of 1 kB are repeated.

In the above process, when the data transfer of 64 kB to the client machine A5 ends earlier than the end deadline, the process for the read request of the client machine B6 is immediately executed as shown in FIG. 5 (a). Be started. On the other hand, when the processing time exceeds the end deadline, as shown in FIG. 5B, at the time when it is confirmed (when the 58 kBth data is transferred), the data is transferred to the client machine A5. Is suspended,
The processing for the read request of the client machine B6 is started. At this time, the client machine A5 is in a data waiting state. Then, as shown in FIG. 6A, after the processing for the other client machines such as the client machine B6 is executed, the data transfer from the 59 kBth point to the temporarily suspended client machine A5 is restarted.

On the other hand, in response to a read request from the client machine B6, the request content confirmation means 2 sends a read request for data (text data) which does not require real-time processing, from the drive number (#A) included in the packet. Judge that there is. Since the amount of data that does not require real-time processing is relatively small and the transfer time is so short that it does not matter, the data transfer control means 3 is read from the disk device 15 without checking the end deadline. Transfer the data. It should be noted that even for data read processing that does not require real-time processing, an end deadline that is long enough to perform the processing is set, and the same processing as that shown in FIG. 5A is performed. You may

Further, when the reading process is interrupted, information indicating the termination of the process may be added to the packet. The operation in this case will be described with reference to FIG. For example, as shown in FIG. 6B, when it is confirmed that the processing time exceeds the end deadline at the time when the 58 kBth data is transferred, the end deadline confirmation means 31 instructs the transfer data generation means 32 to perform the processing. , Instruct to send censorship information.
The transfer data generation means 32 generates the termination information according to the instruction and transfers it to the client machine A5. Then, the server 1 starts the process for the client machine B6 and the like. On the other hand, when the client machine A5 whose data transfer has been aborted receives the abort information, it is assumed that in the next data read processing, the client machine A5 reads from the aborted data (59 kBth) or receives the aborted data. It is selected whether the 64 kB data group is read or the 64 kB data group including the aborted data is read again, and a read request reflecting the selection result is transmitted at the next request.

The interrupted processing of the client machine A5 may be restarted after the processing for all the client machines other than the client machine A5 is completed, or the processing of one client machine is completed. It is also possible to transfer 1 kB of data to the client machine A5 every time.

Next, a method of setting the end deadline in the required time confirmation means 22 will be described.

According to the MPEG1 standard, a data transfer of about 194 kB is required per second in order to reproduce a moving image without stopping it. Therefore, as described above, when there is a request to read data in units of 64 kB from the client, the time that may be taken for one read process is 6
It takes 0.33 seconds from 4 kB / 194 kB. Further, considering the case where moving image data is transferred to N terminals at the same time, the time allowed for the reading process is 0.
33 / N seconds. Therefore, the required time confirmation means 22
Is 0.33 based on the time of read request.
/ N seconds later is set as the end deadline.

In this case, 1 unit per 1 second
Since the data transfer of 64 kB is repeated three times with the allocation time of / N seconds, the end time is not set for the first and second data transfers, and the processing time for each client is set only for the third data transfer. You may make it provide the end time limit which suppresses each total to 1 / N second.

In the MPEG1 data, time information indicating the timing of data reproduction is inserted at a constant data interval. Therefore, the time information may be recognized and the result may be used to confirm the end time.

According to a standard different from MPEG1,
Even for data that requires real-time processing, the end deadline can be set in the same manner. In addition, when a plurality of types of data that require real-time processing are read in the network system, the type of data that requires real-time processing is determined, and the set value for the end deadline may be individually calculated. Good. Further, the time required for the processing in the server and the time required for the network transfer processing may be added to the setting of the end deadline.
In addition to the above method, the time required for the data reading process may be specified on the client machine side. Specifically, the client machine adds information indicating the time required for the data read processing to the read request to be transmitted, and the server machine sets the end deadline based on the added time information. To This makes it possible to easily deal with the case where the amount of data to be read changes within a certain period of time by a special reproduction process such as reproduction of a moving image in fast forward.

Next, another method for determining the type of data that is the target of the read request will be described.

For example, when the disk device 15 is composed of one disk device 15 'as shown in FIG. 7, a plurality of directories a,
Data that requires real-time processing is stored in the directories b and c, and data other than that is stored in the directory a. Then, the request content confirmation means 2 of the server recognizes to which directory of the disk device the read request is directed. This makes it possible to determine whether the data requires real-time processing (type of data) according to the name of the directory.

As described above, the data is divided into blocks according to the types and stored in the disk device, and when the read request is made, the storage area of the data to be read in the disk device can be specified. if,
The type of data can be determined regardless of the number of disk devices or the number of directories. For example, a plurality of directories may be provided in a plurality of disk devices, or one or a plurality of disk devices may be divided into partitions. Further, as shown in FIG. 8, even if there are a plurality of disk device control means 16 and the disk devices are connected to each of them, it is possible to specify the area in which the data requiring real-time processing is stored. do it. In a system having a plurality of disk devices, the data requested to be read by the client may be stored across the plurality of disk devices or may be stored in only one disk device.

As another method of determining the type of data to be read, there is a method of making a determination based on the attribute information of the read-requested data. For example, data such as a moving image used for the purpose of reproduction does not need to be rewritten, and thus has attribute information of “read only”. Therefore, it is "read-only"
When it is requested to read the data having the attribute information, it can be determined that the data requires real-time processing. Alternatively, by newly setting attribute information indicating whether the data requires real-time processing,
You may make it determine from the setting. Further, as another method for determining whether or not the data requires real-time processing, it is possible to make a determination by using information such as an ID number and an IP address in the network system that each client individually has. For example, in a network system, a client that reads data that requires real-time processing may be determined in advance, and when a read request is made from the determined client, the data that is read may be determined to be data that requires real-time processing. . Further, the client that reads the data that requires real-time processing does not need to be fixedly determined when constructing the network system, and means for registering the client that reads the data that requires real-time processing from the server. Information may be provided such that the data to be read is data requiring real-time processing every time data is registered immediately before reading data requiring real-time processing or a request to read data requiring real-time processing is sent to the server. May be added.

As described above, according to the present embodiment, by using a general network of the contention system such as Ethernet, both data requiring real time processing and data not requiring real time processing are efficiently processed. Can be transferred well.

Further, in the present embodiment, when the data transfer to a certain client is completed before the end deadline, the processing to another client is immediately started.
Network usage efficiency is higher than that of time-division network systems.

Further, when the processing for a certain client exceeds the end time limit, the processing for that client is interrupted and the processing for another client is performed, so that the adverse effect of the delay in processing (disturbance or stop of display image, etc.). It is possible to limit the occurrence of (1) to only the client with the processing delay.

<Second Embodiment> Next, a network system according to a second embodiment of the present invention will be described.

The present embodiment has the same configuration as that of the first embodiment described above except for the request content confirmation means 2 and the data transfer control means 3. Therefore, in the following, description of the same parts will be omitted.

FIG. 9 is a diagram showing the configuration of the request content confirmation means 2'and the data transfer control means 3'in this embodiment. In the figure, the request content determination means 21 and the transfer data generation means 32 perform the same operations as those described in FIG. The processing time confirmation means 24 obtains the end deadline and the processing time in the server, and determines in advance whether or not the processing for the read request from the client can meet the end deadline.

In this configuration, when a read request is sent from the client, the request content determination means 21 determines whether or not the request is for data that requires real-time processing. The processing time confirmation means 24 determines the amount of data requested to be read, and the request content determination means 21.
The end time limit is calculated based on the type of data determined in step 1, and the time required to read the requested data is calculated. Here, the time required for reading is the amount of data to be read, the access speed of the disk device 15,
It is calculated based on the data processing speed in the server machine. The processing time confirmation means 24 further determines whether or not the calculated processing time exceeds the end deadline, and if the calculated processing time does not exceed the end deadline, sends a data read request to the network service control means. As a result, the requested data is read and sent to the client. Further, when the processing time exceeds the end deadline, the processing time confirmation means 24 instructs the transfer data generation means 32 to send the abort information without sending the data read request. Upon receiving this instruction, the transfer data generation means 32 generates the termination information and transfers it to the network protocol control means. As a result, only the discontinuation information is sent to the client.

Upon receipt of the abort information, the client requests the data whose transfer has been aborted again or requests the data (data block) following the aborted data at the next read request.

Further, in order to prevent the display of the moving image from being distorted or not displayed due to the termination of the reading process, the client side holds the moving image data immediately before receiving the termination information and stores the retained moving image data. Means for repeatedly displaying may be provided.

As described above, according to the present embodiment, the processing exceeding the end deadline is recognized in advance and the processing exceeding the end deadline is not executed, so that the processing load on the server machine 1 can be reduced.

<Third Embodiment> Next, a third embodiment of the present invention will be described.

This embodiment also has the same structure as the above-mentioned first embodiment except for the request content confirmation means 2 and the data transfer control means 3.

FIG. 10 is a diagram showing the configuration of the request content confirmation means 2 "and the data transfer control means 3" in this embodiment. The data transfer control means 3 ″ in the figure is provided with a data read request generation means 33 for generating a data read request.

In this configuration, the end deadline confirmation means 31
When recognizing that the processing time has exceeded the end deadline, the transfer data generation means 32 terminates the data transfer and informs the data read request means 33 that the end time has passed. In response to this, the data read requesting means 33 gives an instruction to the request time confirming means 22 to read the next data block following the data whose transfer has been aborted. Upon receipt of the instruction, the request time confirmation unit 22 performs the same process as when the read request is received from the request content determination unit 21, and as a result, the data of the next data block is transferred to the client.

Next, a specific example of data transfer performed by the above operation will be described with reference to FIG.

FIG. 11 is a diagram showing how data is transferred in this embodiment. In the figure, the data file 90 requested to be read by the client is 6 in total.
40 kB, read request from client 1,
2, ... 10 (801,802, ... 810) gives 64
It is read in units of kB.

FIG. 11A shows a case where all the data can be normally transferred in response to the read request from the client without exceeding the end time limit. As shown in the figure, first, the read request 1 reads the first 64 kB data block of the data file 90, and the read request 2 reads the 64 kB data block that follows the data block read by the read request 1 described above. Is read, and thereafter, the read request and the reading of the data block corresponding to the read request are repeated.
Causes the last 64 kB data block to be read.

On the other hand, FIG. 11B shows a case where the processing time exceeds the end deadline in the processing for the read request 2 from the client. When the server confirms that the end time limit has been exceeded during the data read process for the read request 2 (for example, at the time of transferring the 60 kBth data), the second time is saved in order to avoid the extension of the playback time at the client. The reading process of the data block is stopped. This puts the client in a data waiting state. Then, the server reads the third data block and transfers it to the client without a read request from the client. Then, in response to the read request 3, the fourth data block is transferred to the client, and the read request 9 sends the data file 90.
Transfer the last data block of.

As described above, according to this embodiment, it is possible to obtain the effect that the reproduction time of the entire moving image data does not increase even in the client in which the reading process is delayed.

In the three embodiments described above, various processes using the end deadline have been described individually, but each process can be combined and implemented.
For example, the processing time confirmation means 24 described in FIG.
A function similar to that of the data read request generation means 33 described in 0 may be added. Further, some clients may interrupt the processing exceeding the end deadline, and other clients may abort the processing exceeding the end deadline.

[0060]

According to the present invention, in a network system for transferring data requiring real-time processing by using a network of contention system, delay of transfer processing of the entire system due to delay of one transfer processing is prevented. be able to.

Further, even if there is a delay in the transfer processing of data requiring real-time processing, the reproduction processing of the data can be completed within the original processing time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a network system according to a first embodiment.

FIG. 2 is a diagram for explaining a problem in a conventional system.

FIG. 3 is a configuration diagram of request content confirmation means and data transfer control means of FIG.

FIG. 4 is a diagram showing a configuration of the disk device of FIG.

5 is a diagram for explaining the operation of the system of FIG.

FIG. 6 is a diagram for explaining the operation of the system of FIG.

7 is a diagram showing another configuration of the disk device of FIG.

8 is a diagram showing another configuration of the disk device of FIG.

FIG. 9 is a block diagram showing a configuration of a request content confirmation unit and a data transfer control unit of the network system according to the second embodiment.

FIG. 10 is a block diagram showing a configuration of request content confirmation means and data transfer control means of a network system according to a third embodiment.

FIG. 11 is a diagram for explaining the operation of the system of FIG.

[Explanation of symbols]

1 ... Server machine, 2 ... Request content confirmation means, 3 ... Data transfer control means, 4 ... Network cable, 5, 6 ... Client machine, 10 ... Operating system,
11 ... Network device, 12 ... Network device control means, 13 ... Network protocol control means, 14 ... Network service control means, 15 ... Disk device, 16 ... Disk device control means, 17 ... Disk access control means, 21 ... Request content determination Means, 22 ...
Request time confirming means, 23 ... end deadline storing means, 24 ... processing time confirming means, 31 ... end deadline confirming means, 32 ... transfer data generating means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Kurosu 1099, Ozenji, Aso-ku, Kawasaki-shi, Kanagawa Inside the Hitachi, Ltd. System Development Laboratory (72) Inventor, Yoshihiro Yokoyama 1099, Ozen-ji, Aso-ku, Kawasaki, Kanagawa Hitachi, Ltd. System Development Laboratory (72) Inventor Toshihiro Inoue 1099, Ozenji, Aso-ku, Kawasaki-shi, Kanagawa Ltd. Inside Hitachi System Development Laboratory

Claims (11)

[Claims] 1. A server device, a plurality of terminal devices for outputting a data read request to the server device, and a network for contention system connecting the server device and the terminal device, the server device comprising: A network system having storage means for storing data including data requiring real-time processing, and means for transferring the data corresponding to the received read request from the storage means to the terminal device, wherein the server device is A determination unit that determines the content of a read request from the terminal device, a unit that sets an end deadline for the transfer process of the data corresponding to the read request according to the determination result of the determination unit, and the transfer process. If it is done beyond the end deadline,
A network system comprising: a transfer limiting unit that interrupts or cancels the transfer process. 2. The network system according to claim 1, wherein the transfer control means, when the transfer processing is interrupted or aborted, sends data indicating the interruption or abortion of the processing to the terminal device. A network system characterized by outputting to. 3. The network system according to claim 1, wherein the server device has means for previously obtaining the time required for the transfer processing, and the transfer control means has the end time limit as the obtained time. When exceeding the limit, the network system outputs data indicating termination of the transfer process to the terminal device, and does not transfer the data corresponding to the read request. 4. The network system according to claim 1, wherein the server device terminates the transfer process when the transfer process is performed over an end deadline, and transfers the data after aborting the transfer process. A network system, wherein data following the missing data is transferred without a read request from the terminal device. 5. The network system according to claim 1, wherein when the transfer process is aborted, the terminal device requests a next read of data that has not been transferred due to the abortion of the transfer process. A network system characterized by occasional requests. 6. The network system according to claim 1, wherein the data requiring real-time processing is moving image data, and the terminal device displays moving image data output from the server device. Display means, means for holding the moving picture data, and means for displaying the held moving picture data on the display means when the transfer process is interrupted or aborted in the server device. Characteristic network system. 7. The network system according to claim 6, wherein the storage means is a disk device, and the determination means is a disk number, a drive number, a directory name of the disk device included in the read request. A network system characterized by making a determination based on at least one of a file name and a file attribute. 8. The network system according to claim 7, wherein the determination unit makes a determination based on unique information set in the terminal device that has output the read request. Network system. 9. The network system according to claim 8, wherein the end deadline is set based on time information included in the moving image data corresponding to the read request. 10. The network system according to claim 8, wherein the end time limit is set based on the number of terminal devices that access the server device. 11. The network system according to claim 9, wherein the server device performs a transfer process for a read request from the plurality of terminal devices at predetermined intervals. It is characterized by comprising means for sequentially adding time to each terminal device, and for a terminal device whose addition result exceeds the termination deadline, the transfer processing in the predetermined period is interrupted or aborted. Network system.