JP3496649B2 - Data distribution method and system, scheduling device, scheduling program, and storage medium storing scheduling program - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data distribution method and system, a scheduling device, a scheduling program, and a storage medium storing the scheduling program, and more particularly to a client terminal, a database server accommodating the client terminal, and a scheduling function. The present invention relates to a data distribution method and system for performing data transmission between servers using burst transfer in a data distribution system, a scheduling device, a scheduling program, and a storage medium storing the scheduling program.

[0002]

2. Description of the Related Art As a conventional data distribution method, when a client makes a data distribution request to a database server via a client terminal, if the data exists in the database server, the requested data is requested. Send to the original client terminal. If the database server does not have the data requested by the client terminal, the data is delivered to the client terminal by packet transfer when the data is acquired from the outside.

[0003]

However, in the above-described conventional data distribution method, when the data requested by the client does not exist in the data server accommodating the client, the data corresponding to the request will arrive at the database server. It is not possible to tell the client how soon it will be delivered, because the time cannot be determined accurately.

In packet transfer, since one link is used for a plurality of data transfers at a time, it is difficult to accurately calculate the time until the data transfer between nodes is completed.

The present invention has been made in view of the above points, and data transfer between database servers can be performed in accordance with a schedule, whereby the arrival time of request data at the database server can be calculated. A method and system, a scheduling device, a scheduling program, and a storage medium storing the scheduling program are provided.

Another object of the present invention is to provide a data distribution method and system capable of accurately performing link transfer time of each data, a scheduling device, a scheduling program and a storage medium storing the scheduling program. .

A further object of the present invention is to provide a data distribution method and system capable of accurately estimating the total transfer time of each data, a scheduling device, a scheduling program, and a storage medium storing the scheduling program. Is.

[0008]

FIG. 1 is a diagram for explaining the principle of the present invention.

The present invention (claim 1) is a system comprising at least one client terminal and a plurality of database server groups accommodating the client terminal,
In a data distribution method for distributing data from the database server to the client terminal, the client terminal sends a data distribution request to the database server (step 1), and the database server requests the data distribution request. It is determined whether the existing data exists in its own server (step 2), and if it exists, the data is transmitted to the client terminal (step 3). If it does not exist, the data held by each database server is checked. The data requested by the client terminal is requested to the scheduling device that manages and has a scheduling function (step 4),
The scheduling device refers to the data management table for the data requested by the database server, searches the database server that holds the data, determines the data transfer schedule between the database servers (step 5), and determines each database. The server is notified of the schedule (step 6), the estimated arrival time of data is also calculated for the database server of the data request source (step 7), and the database server of the data request source is notified (step 8), The database requesting source notifies the client terminal of the estimated arrival time of the data notified from the scheduling device (step 9), and the database server which has received the schedule and the data transfer request from the scheduling device follows the schedule. By burst transfer, the requested data is transmitted to the database server of the data request source (step 10), and the database server of the database request source, upon receiving the data, transmits the data to the client terminal (step 11) and The data is held as cache data (step 12).

FIG. 2 is a block diagram showing the principle of the present invention.

The present invention (claim 2) provides at least one client terminal 100 and the client terminal 100.
Is composed of a plurality of database server 200 groups for accommodating
In the data distribution system for distributing data to 0, the client terminal 100 transmits the data distribution request to the database server, and the distribution request transmitting means 11
0 and receiving means 120 for receiving data corresponding to the data distribution request from the database server, and the database server 200 determines whether the data requested by the data distribution request acquired from the client terminal exists in its own server. Judgment means 210 for judging, data transmission means 230 for transmitting data held in its own server or data acquired from another database server to a client terminal, and judgment means 210, if none exist, each database server The data requesting unit 220 that manages the data held by the client and requests the data requested by the client terminal to the scheduling apparatus having the scheduling function, and the schedule that is acquired from the scheduling apparatus 300. The scheduling device 300 includes a burst transfer unit 240 for burst-transferring data to the database server and a cache unit 250 for storing data acquired from another database server 200 as cache data. When there is a data request from the data table 310 that manages the database server 200 and the database server 200, the data table 310 is referenced to search for the database server 200 that holds the requested data. The data transfer schedule is determined, the schedule determining means 320 for notifying each database server 200 of the schedule, and the estimated arrival time of data to the database server 200 of the data request source are calculated, and the data request source data And an estimated arrival time calculation means 330 to notify the base.

The present invention (claim 3) is a data distribution system for distributing data from the database server to the client terminal, which comprises at least one client terminal and a plurality of database server groups accommodating the client terminal. , A scheduling device that manages the schedule of data delivery between database servers, and refers to the data table that manages the data held by each database server and the data table when the database server requests data distribution. And a search means for searching the database server holding the requested data, a data transfer schedule between the searched database server and the data request source database, and a schedule for notifying the schedule to each database server. Has a Le determining means calculates the expected arrival time of the data to the data requesting database server, and a scheduled arrival time calculating means for notifying said data requesting database.

The present invention (claim 4) is a data distribution system comprising at least one client terminal and a plurality of database server groups for accommodating the client terminal, and for distributing data from the database server to the client terminal. , A scheduling program that manages the schedule of data delivery between database servers, managing the process of receiving a data delivery request from the database server and the data held by each database server when a data delivery request is made. The data table to be searched is used to determine the search process that searches the database server that holds the requested data, and the data transfer schedule between the searched database server and the database that requested the data. Has a schedule determination process of notifying the schedule over server calculates the expected arrival time of the data to the data requesting database server, and a scheduled arrival time calculating process for notifying the data requesting database.

The present invention (claim 5) is a data distribution system comprising at least one client terminal and a plurality of database server groups accommodating the client terminal, and for distributing data from the database server to the client terminal. A storage medium storing a scheduling program for managing a schedule of data delivery between database servers, the process of receiving a data delivery request from the database server,
When there is a data distribution request, a search process that searches the database server that holds the requested data by referring to the data table that manages the data that each database server holds, and the searched database server Data transfer schedule between the data request source database and the schedule determining process for notifying each database server of the schedule, and the estimated data arrival time to the data request source database server, and calculating the data request source database. And an estimated time of arrival calculation process.

As described above, in the present invention, the schedule function for determining the scheduling of data distribution between the database servers is provided, and the data distribution schedule is determined based on the table of data held by each server in the schedule function. Then, it notifies the arrival time of the data. This will cause the database server to
It is possible to notify the client of the estimated arrival time of data.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows the configuration of the data distribution system of the present invention.

The data distribution system shown in the figure includes a network 140 and a plurality of client terminals 121-12.
6. Database 10 accommodating the client terminal
1 to 104 and a scheduling device 130. In the example of the figure, the database server 101
Contains the client terminal 121, the database server 102 contains the client terminal 122, and the database server 103 contains the client terminal 123, 1.
The database server 104 accommodates the client terminals 125 and 126.

The client terminals 121 to 126 are database servers 101 to 1 which accommodate the clients.
Issue a data distribution request to 04.

When a data distribution request is issued from each of the client terminals 121 to 126 housed in each of the database servers 101 to 104, based on the request,
It is determined whether the data is in its own server, and if there is, the data is delivered to the client terminal. Also,
If the server does not have the requested data, the data distribution request is sent to the scheduling device 130. The transfer schedule between the database servers and the data arrival time are acquired from the scheduling device 130. Accordingly, the database servers 101 to 104 notify the data arrival time to the client terminals 121 to 126 accommodated by the server. In addition, the requested data is burst-transferred to another database server based on the transfer schedule, and the database server that has acquired the data delivers the data to the client terminal that issued the request when the data arrives.

The scheduling device 130 holds the data table of each of the database servers 101 to 104, determines a schedule for transferring the data not held by each server, and notifies each server. At this time, the estimated arrival time of the data is notified to the database server that requested the data distribution.

Next, the operation of the above configuration will be described.

FIG. 4 is a flow chart of the operation in the data distribution system of the present invention. In the following description, it is assumed that the client terminal 121 sends a data distribution request to the database server 101, but the same operation is performed for other client terminals and database servers.

Step 101) Client terminal 12
1 is a database server 1 that accommodates the terminal 121.
A data distribution request is transmitted to 01.

Step 102) Database server 1
01 analyzes the distribution request received from the client terminal 121.

Step 103) Client terminal 12
It is determined whether or not the data requested by 1 exists in its own server. If it exists, the process proceeds to step 104, and if it does not exist, the process proceeds to step 105.

Step 104 Database server 10
1 is a client terminal 1 that requests the requested data.
21 to 21.

Step 105) Database server 1
Of the data requested by the client terminal 121, 01 transmits to the scheduling device 130 a distribution request for data that is not held by the server itself.

Step 106) The scheduling device 130 analyzes the distribution request received from the database server 101, determines the data transmission schedule in the server building, and notifies the database server 101 of it. At this time,
The estimated arrival time of data to the database server 101 is also calculated and notified.

Step 107) Database server 1
01 notifies the client terminal 121 of the estimated data arrival time.

Step 108) Database server 1
Among the database servers other than 01, the database server holding the data notified from the scheduling device 130 transfers the data to each other by the burst transfer according to the schedule.

Step 109) Database server 1
When 01 acquires the data acquired by the burst transfer, the acquired data is transmitted to the client terminal 121, and the acquired data is stored as cache data.

FIG. 5 is a diagram for explaining a data distribution method between database servers according to the present invention.

FIG. 7A shows an example of using line resources in packet transfer or the like simultaneously for a plurality of data distributions, and FIG. 9B shows an example of burst transfer between databases in the present invention. An example is shown in which line resources are used for time division, and at a certain moment, one data distribution is fully utilized. The burst transfer between the database servers in the above step 108 uses FIG. In the packet transfer shown in FIG. 7A, one link is used for a plurality of data transfers at a time, and therefore the time until the data transfer is completed cannot be accurately calculated between the nodes. In the scheduling device 130, the burst transfer shown in FIG. 7B is used to accurately calculate the data arrival time.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 6 shows the configuration of a data distribution system according to an embodiment of the present invention.

In the figure, the database server 301
In the network 310 accommodating ~ 305, there is a line dedicated to burst transfer between each server. This line may be physically constructed, or may be logically constructed using ATM (asynchronous mode) VP (virtual path) or the like.

The data to be distributed to the client terminals 321 to 327 must be transported and stored from outside the network 310 to any of the internal database servers 301 to 305 before being transferred to the database servers 301 to 305. is there. Any means may be used as long as the storage is completed at an appropriate time. Examples include transmission using a computer network, transportation of a physical storage medium (CD, DVD disk, etc.), and the like.

Each of the client terminals 321 to 327 communicates with the database server accommodating itself through the line of the ISP (Internet service provider) 331 to 335 being used.

The scheduling device 340 includes a data management table for managing the data held by the database servers 301 to 305, and the database servers 301 to 30.
5 holds a table of data requested to be distributed, and determines a data transfer schedule between the servers based on the table. FIG. 7 is an example of a table of data (contents) held by each database server according to the embodiment of the present invention.
As shown in the figure, the scheduling device 340 holds the data (content) held by each database server.

Next, a method of determining a schedule in the scheduling device 340 will be described.

When the scheduling device 340 determines the schedule, as shown in FIG.
There is a method that uses an algorithm for the g coloring problem.
In this method, natural values are assigned to each node of the graph and each multiple side such that each node v of the graph → point capacity f (v), each multiple side uv of the graph → side capacity g (uv).

Next, each side is colored according to the following rules.

Rule 1: Each node v has at most f (v) lines of the same color; Rule 2: Each multiple side E (uv) has at most g sides of the same color.
(Uv) book; at this time, it is possible to paint using as few colors as possible (if you decide to use as many colors as you like, you can always color the graph so as to satisfy the above rules) Is an algorithm for calculating a sufficient number of colors and a method of painting using those colors in the shortest possible time.

When the above algorithm for the fg coloring problem is applied to the present invention, each database server is regarded as a node of the graph, and u and v are connected by multiple edges by the number of files transmitted and received between the servers u and v. And As a result, the number of transmission / reception ports corresponds to the point capacity. In addition, the number of burst transfer that can be performed simultaneously between servers corresponds to the side capacity. By applying the above algorithm in such a state, burst transfer that can be simultaneously performed between the servers in the network shown in FIG. 9A is given as shown in FIG. Then, when the file transfer to be executed and the number of transmission / reception ports of each server are given as shown in (c) of the figure, the transmission schedule is determined by coloring the graph shown in (d) of the figure. it can. The specific schedule is as shown in FIG.

The method for determining the schedule is not limited to the above example, and any calculation method capable of performing calculations for schedule management may be used.

Next, a method of calculating the transfer time when the burst transfer is used will be described.

The speed of the line connecting the adjacent nodes is C
[Mbps], and the size of the content to be transmitted is L [M
bit]. It should be noted that C is a fixed value determined by the performance of the line, and L varies depending on the content to be transmitted, but here it is assumed to be the same.

The transfer time when contents are sent by using burst transfer between adjacent nodes is calculated by T = L ÷ C [s].

In the case of a system in which one line is shared by a plurality of connections, it is unclear how much line resources can be used, so the transfer time is L ÷ (C-α) [s]. Here, α is uncertain.

It is also possible to construct the schedule determining function and the estimated arrival time calculating function of the scheduling device in the above embodiment as a program. It is also possible to install and execute the constructed program in the CPU of a computer used as a scheduling device.

In addition, the constructed program is stored in a hard disk device, a floppy (registered trademark) disk, a CD-
The present invention can be easily realized by storing it in a portable storage medium such as a ROM and installing it when carrying out the present invention.

The present invention is not limited to the above embodiments, and various modifications and applications are possible within the scope of the claims.

[0052]

As described above, according to the present invention, it is possible to notify the arrival time of the requested data to the server in advance by performing the data transfer between the database servers according to the schedule. As a result, it is possible to notify the client of the data distribution request source, which the database server accommodates, of the scheduled data distribution time.

By performing burst transfer between the database servers, the link transfer time of each data can be accurately calculated.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a principle configuration diagram of the present invention.

FIG. 3 is a configuration diagram of a data distribution system of the present invention.

FIG. 4 is a flowchart of an operation in the data distribution system of the present invention.

FIG. 5 is a diagram for explaining a data distribution method between database servers of the present invention.

FIG. 6 is a configuration diagram of a data distribution system according to an embodiment of the present invention.

FIG. 7 is an example of a table of data (contents) held by the server, which is the core of one embodiment of the present invention.

FIG. 8 is a diagram illustrating an f coloring algorithm for schedule calculation in the scheduling device according to the embodiment of the present invention.

FIG. 9 is an application example of a coloring algorithm according to an embodiment of the present invention.

FIG. 10 is an example of a schedule created by the scheduling device according to the embodiment of the present invention.

[Explanation of symbols] 100 clients 101-104 database server 110 Delivery Request Transmission Means 120 receiving means 121-126 Client terminal 130 Scheduling device 140 networks 200 database server 210 determination means 220 Data Request Means 230 Data transmission means 240 burst transfer means 250 cash means 300 scheduling device 310 Data table 320 Schedule determination means 330 Estimated arrival time calculation means 301-305 database server 321 to 327 Client terminal 331-335 ISP 340 scheduling device

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Abe 2-3-1, Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) Reference JP-A-11-85631 (JP, A) ( 58) Fields surveyed (Int.Cl. ⁷ , DB name) G06F 13/00 G06F 12/00

Claims (5)

(57) [Claims] 1. A data distribution method for distributing data from the database server to the client terminal in a system comprising at least one client terminal and a plurality of database server groups accommodating the client terminal, the client terminal comprising: , Sending a data delivery request to the database server, and determining whether the data requested by the data delivery request exists in the server itself in the database server. When not present, the data held by each database server is managed, and the data requested by the client terminal is requested to a scheduling device having a scheduling function. The apparatus refers to the data management table for the data requested by the database server, searches the database server holding the data, determines the data transfer schedule between the database servers, and determines the schedule for each database server. The data request source database server, the data arrival schedule time is also calculated, and the data request source database server is notified, and the data request source database server is notified from the scheduling device. The database server which has notified the client terminal of the expected arrival time of the data and has received the schedule and the data transfer request from the scheduling device transmits the requested data by burst transfer according to the schedule. And transmitting the data to the client terminal and holding the data as cached data. 2. A data distribution system comprising at least one client terminal and a plurality of database server groups accommodating the client terminal, for distributing data from the database server to the client terminal, wherein the client terminal is A distribution request transmission unit that transmits a data distribution request to the database server, and a reception unit that receives data for the data distribution request from the database server, wherein the database server is acquired from the client terminal. Determination means for determining whether or not the data requested by the data distribution request exists in the server itself; data held in the server itself or data for transmitting data acquired from another database server to the client terminal Transmission means, When the determination unit does not exist, a data request unit that manages the data held by each database server and requests the scheduling device having a scheduling function to distribute the data requested by the client terminal. A burst transfer means for burst-transferring data to a database server that is a data request source based on a schedule acquired from the scheduling device, and a cache means for storing data acquired from another database server as cache data. However, the scheduling device holds a requested data by referring to the data table that manages the data held by each database server and the data table when the database server requests the data. Are The database server is searched, the data transfer schedule between the database servers is determined, the schedule determination means for notifying each database server of the schedule, and the estimated arrival time of data to the database server of the data request source are calculated, and the data request source A data delivery system, comprising: an estimated arrival time calculating means for notifying a database. 3. A data distribution system, comprising at least one client terminal and a plurality of database server groups accommodating the client terminals, for distributing data from the database server to the client terminals. A scheduling device that manages the schedule of a data table that manages the data held by each database server, and when there is a data distribution request from the database server, the data table is referenced and requested. Retrieval means for retrieving a database server holding data, and schedule deciding means for deciding a data transfer schedule between the retrieved database server and the data request source database and notifying the schedule to each database server. And an estimated arrival time calculating means for calculating an estimated arrival time of data to the database server of the data request source and notifying the estimated data arrival time to the database of the data request source. 4. A data distribution system, comprising at least one client terminal and a plurality of database server groups accommodating the client terminals, for distributing data from the database server to the client terminals. A scheduling program for managing the schedule of a process, including a process of receiving a data distribution request from the database server, and a data table managing data held by each database server when the data distribution request is made. The database server that holds the requested data, and the data transfer schedule between the searched database server and the database that requested the data. A scheduling program, comprising: a schedule determination process for notifying a module and an estimated arrival time calculation process for calculating an estimated arrival time of data to a data request source database server and notifying the data request source database. 5. A data distribution system, comprising at least one client terminal and a plurality of database server groups accommodating the client terminals, for distributing data from the database server to the client terminals. Is a storage medium storing a scheduling program for managing the schedule of, a process of receiving a data distribution request from the database server, and managing data held by each database server when the data distribution request is made. The data table to be searched is used to determine the search process that searches the database server that holds the requested data, and the data transfer schedule between the searched database server and the database that requested the data. It has a schedule determination process of notifying the base server of the schedule, and an estimated arrival time calculation process of calculating an estimated arrival time of data for the database server of the data request source and notifying the database of the data request source. A storage medium that stores a scheduling program.