JP2006012005A - Autonomous storage device, autonomous storage system, network load balancing program, and network load balancing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an autonomous storage device capable of preventing the reduction in throughput in accessing a content in a load distributed state in an autonomous storage system so as not to cause deviation of content capacity. <P>SOLUTION: The autonomous storage device 2 comprises a load state detection means 261a detecting a load state; and a role changing means 263 changing, based on the detected load state, the role of a primary content 30a stored in a content storage means 30 to a backup content 30b, or changing the role of the backup content 30b to the primary content 30a. The role of a content is changed between the autonomous storage devices 2 through a network, whereby load distribution is performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an autonomous storage apparatus, an autonomous storage system, a network load distribution program, and a network load distribution method capable of distributing a load applied to the network or apparatus when content (data) is distributed and stored on the network. About.

  In recent years, the amount of content data used in computers continues to increase, and along with this, the capacity of storage devices (storage) such as hard disks for storing content has also increased. However, since the storage device may fail, content loss due to the storage device failure increases with an increase in the capacity of the storage device. Therefore, recently, an autonomous storage system has been proposed as a technique for improving the reliability, safety, availability, and expandability of a storage device (see, for example, Non-Patent Document 1).

  In this autonomous storage system, a plurality of autonomous storage devices connected to a network exchange load information, failure information, etc. of the devices via the network, and based on predetermined autonomous distributed management rules, The content is copied and moved in cooperation with the storage device. Thus, in the autonomous storage system, in addition to load distribution and failure recovery when storing content, the autonomous storage apparatus can be expanded and removed.

  Here, a content storage method in the conventional autonomous storage system will be described with reference to FIG. FIG. 6 is a schematic diagram showing an example of a state in which content is distributed and stored in a conventional autonomous storage system, and is an autonomous storage device constituting the autonomous storage system (actually content storage means in the autonomous storage device). Shows a state in which the content is stored. Here, as an example, description will be made assuming that the number of autonomous storage apparatuses is four and the number of contents is sixteen.

In each of the autonomous storage devices (2B _{1 to} 2B ₄ ) constituting the autonomous storage system 1B shown in FIG. 6, identification information (identifier) for uniquely specifying the logical adjacency is set. The first autonomous storage device is 2B ₁ , the second autonomous storage device is 2B ₂ , the third autonomous storage device is 2B ₃ , and the fourth (first last) autonomous storage device is 2B ₄ . In addition, uniquely identified identification information (for example, a file name, a number, etc.) having a logical magnitude relationship is set in the content, and the content having the smallest identification information is the C1, 2nd. The content having the smallest identification information is C2, and similarly, the content having the 16th smallest (largest) identification information is C16.

  Further, the autonomous storage system 1B divides the content storage means of each autonomous storage device 2B into a primary area P and a backup area B, and stores the original content in the primary area P and the backup of the original content in the backup area B. To do. Hereinafter, the content stored in the primary area P is referred to as primary content, and the content stored in the backup area B is referred to as backup content.

That is, the autonomous storage system 1B, the identification information is the smallest content group (C1 -C4) primary regions P ₁ of the autonomous storage device 2B _1, the autonomous storage and the identification information is smaller content group second (C₅-C₈) primary region P ₂ of the device 2B _2, the autonomous storage device 2B ₃ primary regions P ₃ the identification information is smaller content group (C9 to C12) in the third, a large identification information 4 th is small (most identification information ) Store the content groups (C13 to C16) in the primary area P ₄ of the autonomous storage device 2B ₄ .

The autonomous storage system 1B stores backup content in the backup area B of the content storage means of each autonomous storage device 2B that is logically adjacent. That is, to store the backup content C'1~C'4 corresponding to the primary content of the autonomous storage device 2B ₁ (C1 -C4) the backup area B ₂ of the autonomous storage device 2B _2. Similarly, the backup content (C'5~C'8) backup area B ₃ a corresponding to the primary content (C₅-C₈), the backup content corresponding to the primary content (C9~C12) (C'9~C' 12) are stored in the backup area B ₄ respectively. Note that the backup content (C'13~C'16) corresponding to the primary content (C13~C16) is stored in the backup area B ₁ of the autonomous storage device 2B ₁ as the first logical.

As described above, the autonomous storage system 1B distributes the load to each autonomous storage device 2B to distribute the load, and arranges the backup content in a chain in the logically adjacent autonomous storage device 2B (check this arrangement). This is called “Indian declustering” and stored, so that even if a failure occurs and the content is lost, the content can be recovered.
In addition, the autonomous storage system 1B distributes the load by moving the content stored in the autonomous storage device 2B, which has become heavily loaded, to another autonomous storage device 2B during operation.

Here, with reference to FIG. 7 (refer to FIG. 6 as appropriate), the load distribution operation during operation in the conventional autonomous storage system will be described. FIG. 7 is a flowchart showing the load balancing operation in the conventional autonomous storage system. Here, the operation of the autonomous storage device 2B ₄ is omitted.

First, each autonomous storage device 2B of the autonomous storage system 1B detects a load state and determines whether or not the autonomous storage device 2B is in an overload state (step S11, step S11 ′, step S11 ″). Now, it is assumed that the autonomous storage device 2B ₂ has the largest load and is in an overload state.

At this time, the autonomous storage device 2B ₂ determines the content to be moved to another autonomous storage device 2B (step S12), and determines whether the content is currently being operated (accessed) (step S13). The operation waits until the operation is completed (Yes in step S13). Here, it is assumed that the content to be moved is the primary content C5 and the backup content C′5.
Then, at the stage where the operation is completed in step S13 (No in step S13), and the autonomous storage device 2B ₂ prohibits access to the primary content C5 (locked) (Step S14).

Moreover, the autonomous storage device 2B _2, to the autonomous storage apparatus 2B _3, sends an instruction to prohibit access to backup content C'5, the autonomous storage device 2B _3, to the backup content C'5 Access is prohibited (step S15).
Then, at the stage where access to the backup content C′5 is prohibited, the autonomous storage device 2B ₂ transmits (copies) a copy of the primary content C5 to the autonomous storage device 2B ₁ (step S16).

Then, the autonomous storage device 2B ₁ stores a copy of the primary content C5 received from the autonomous storage device 2B ₂ in the access prohibited (locked) state in the primary area P ₁ (step S17), and sends a completion notification to the autonomous storage device 2B _2. Notify

Furthermore, the autonomous storage apparatus 2B ₂ moves the primary content C5 to the backup area B ₂ as the backup content C′5 in the access prohibited state and stores it (step S18). Then, the autonomous storage apparatus 2B ₂ instructs the autonomous storage apparatus 2B ₃ to delete the backup content C′5 stored in the backup area B ₃ .

Then, the autonomous storage device 2B ₃ deletes the backup content C′5 stored in the backup area B ₃ (step S19), and notifies the autonomous storage device 2B ₂ of the completion of deletion.
Moreover, the autonomous storage device 2B ₂ releases the access prohibition backup content C'5 is moved to the backup area B ₂ of the autonomous storage devices 2B in ₂ (step S20), the autonomous storage devices 2B _1, primary An instruction to cancel the access prohibition of the content C5 is given.
Then, the autonomous storage device 2B ₁ cancels the access prohibition of the primary content C5 (step S21), and notifies the autonomous storage device 2B ₂ that the access prohibition has been canceled.
Then, when the autonomous storage device 2B ₂ is notified by the autonomous storage device 2B ₁ of the access prohibition release of the primary content C5, the load distribution operation ends.

As described above, when the autonomous storage system 1B operates, the storage state of the content shown in FIG. 6 becomes the state shown in FIG. FIG. 8 is a schematic diagram showing a storage state of content after a load balancing operation in a conventional autonomous storage system.
As shown in FIG. 8, since the number of primary contents is reduced from the autonomous storage device 2B ₂ having a large load, access to the autonomous storage device 2B ₂ is reduced, and the load is distributed. . Even in this case, chained declustering is maintained, and it is possible to recover from a failure.
Daisuke Ito, “Cluster Reconfiguration Using Load Balancing Mechanism of Distributed Directory on Autonomous Disks”, 13th Data Engineering Workshop Proceedings, DEWS2002 C3-3, IEICE Technical Committee on Data Engineering (2002)

However, in the above-described conventional technology, it is necessary to transfer a copy of the content (primary content) between the autonomous storage apparatuses when performing load distribution. Therefore, a load is applied to the network, and the client computer or the like is autonomous. There is a problem that throughput when content is accessed to the storage system is lowered.
Further, in the conventional technology, when load balancing is performed, it is necessary to move content (moving from primary content to backup content) within the autonomous storage device. There is.

Furthermore, in the conventional technique, when the load is distributed, the content is moved, so that the number of contents stored in each autonomous storage device changes. For example, as shown in FIG. 8, the number of contents of the autonomous storage apparatus 2B ₁ is 8 (C1 to C4, C′13 to C′16) to 9 (C1 to C5, C′13 to C ′). 16), the number of contents of the autonomous storage device 2B ₃ is reduced from 8 (C9 to C12, C′5 to C′8) to 7 (C9 to C12, C′6 to C′8). End up.
As described above, since the number of contents of each autonomous storage device changes, the amount of data stored in each autonomous storage device is biased, and when the data amount of a certain autonomous storage device reaches the maximum capacity, Since storage is limited, there is a problem that the storage capacity of the entire autonomous storage system is reduced.

  The present invention has been made in view of the above problems. In an autonomous storage system, during load balancing, a decrease in throughput when accessing content is prevented and stored in each autonomous storage device. It is an object of the present invention to provide an autonomous storage device, an autonomous storage system, a network load distribution program, and a network load distribution method that do not cause a bias in the capacity of existing content.

  The present invention has been developed to achieve the above object. First, the autonomous storage device according to claim 1 is connected to a network in a plurality, and the contents are distributed as original contents and backup contents. The autonomous storage device to be stored is configured to include content storage means, role information storage means, association information storage means, load state detection means, role change means, and content operation control means.

  According to such a configuration, the autonomous storage device stores the original content (primary content) in the content storage unit and the backup content of the original content stored in another autonomous storage device connected to the network. At this time, for each content stored in the content storage unit, the autonomous storage apparatus stores role information indicating whether the content is the original content or the backup content in the role information storage unit. As described above, the autonomous storage device manages whether each content is used as original content or used as backup content in association with role information, so that the role is changed only by changing this role information. be able to. In the content storage means, it is desirable that the content is managed in ascending or descending order in association with identification information indicating the arrangement order.

  Further, the autonomous storage device, for each content stored in the content storage unit, stores the original content and the backup content in the content and the content stored in the content storage unit of another autonomous storage device. The association information indicating the association is stored. As a result, when the original content and the backup content are stored across the autonomous storage devices, the position of the backup content corresponding to the original content or the position of the original content corresponding to the backup content can be quickly searched. it can.

  Then, the autonomous storage device detects the load state of the autonomous storage device and other autonomous storage devices based on the number of accesses per unit time to the content by the load state detection means, and determines the load state between the autonomous storage devices. By exchanging with, it is recognized which autonomous storage device has a large load. Then, the autonomous storage device associates the content stored in the content storage unit of the autonomous storage device with the largest load in the load state detected by the load state detection unit by the role changing unit, and the content and the association information. The role information is updated by changing the role of the content that has been added. That is, the role of the original content stored in the content storage unit of the autonomous storage device with a large load is changed to the backup content, and the content associated with the original content is set as the original content (primary content).

  Then, the autonomous storage apparatus performs an operation (for example, reading, writing, etc.) on the original content based on the role information stored in the role information storage unit by the content operation control unit. As a result, the load on the autonomous storage device having a large load is reduced, and the load is distributed to other autonomous storage devices.

  The autonomous storage device according to claim 2 is the autonomous storage device according to claim 1, wherein the content storage means associates the original content associated with the identification information indicating the arrangement order with another autonomous storage. The backup content corresponding to the original content which is stored in the content storage means of the apparatus and is continuous before or after the arrangement order is stored.

  According to such a configuration, the autonomous storage device stores the original content associated with the identification information indicating the arrangement order in the content storage unit and the content storage unit of the other autonomous storage device, The backup content corresponding to the subsequent original content is stored. As a result, backup contents are continuously held so as to overlap each autonomous storage apparatus. In addition, since the autonomous storage device identifies the original content and the backup content based on the role information, the original content and the backup content are stored in the content storage unit without distinguishing the area, and only the role information is changed. As a result, the roles of the original content and the backup content are changed.

  Furthermore, in the autonomous storage device according to claim 3, in the autonomous storage device according to claim 2, when the load state detected by the load state detection unit is an overload state, the role changing unit includes: The original content stored in the content storage means, or the original content group continuous in the arrangement order to the first or last original content, the role of the content is changed to backup content, and the corresponding backup content group is It is characterized by changing its role to the original content.

  According to such a configuration, when the autonomous storage device is overloaded, the autonomous storage device is the first or last in the order of arrangement in the original content stored in the content storage unit by the role changing unit. Change the original content to backup content. Accordingly, the role of the backup content stored in the content storage means of the logically adjacent autonomous storage device that stored the backup content of the original content is changed to the original content (primary content). The sequence of the original contents is maintained in the autonomous storage apparatus that is continuous with the original storage apparatus. When changing the role of the original content to the backup content, the roles of a plurality of original contents (original content group) that are continuous with the original content in the arrangement order are collectively changed to the backup content, and the original content group Corresponding backup content (a backup content group) may be collectively changed to the original content.

  The autonomous storage system according to claim 4 is an autonomous storage system that stores content in a distributed manner as original content and backup content, and is connected to a network. A plurality of autonomous storage devices according to claim 1 and corresponding to the original content stored in the content storage means of the autonomous storage device in an overloaded state among the plurality of autonomous storage devices; The role of the backup content stored in the content storage means of another autonomous storage device is changed.

  According to such a configuration, the autonomous storage system recognizes the load state between the autonomous storage devices connected to the network, and stores the original content stored in the content storage unit of the autonomous storage device that is in an overload state. The role is changed to the backup content, and the role of the backup content stored in the content storage unit of another autonomous storage device corresponding to the original content is changed to the original content. As a result, the load generated by accessing the original content is distributed to other autonomous storage apparatuses.

  Furthermore, the network load distribution program according to claim 5 is provided with a content storage means for storing content, and is connected to a network so that the content is distributed and stored as original content and backup content. In order to distribute the load, the computer in the autonomous storage apparatus functions as a load state detection unit, a role change unit, and a content operation control unit.

  According to this configuration, the network load distribution program detects the load states of the autonomous storage device and other autonomous storage devices based on access to the content by the load state detection unit. This recognizes which autonomous storage device has a large load. Then, the network load distribution program is stored in the content storage unit and the content storage unit of another autonomous storage device based on the load state detected by the load state detection unit by the role changing unit. The role information is updated by changing the role of the content. Further, the network load distribution program operates the original content by the content operation control unit based on the role information stored in the role information storage unit. As a result, the load on the autonomous storage device whose role is changed to the backup content is distributed to the autonomous storage device whose role is changed to the original content.

  According to a sixth aspect of the present invention, there is provided a network load distribution method in which a plurality of autonomous storage devices including content storage means for storing content are connected to the network, whereby the content is distributed and stored as original content and backup content. In the autonomous storage system, a network load distribution method for distributing the load among the autonomous storage devices, comprising: a load state detection step, an overload determination step, an access prohibition step, a role change step, an access release step, It is characterized by including.

  According to this procedure, the network load balancing method detects the load state of each autonomous storage device in the load state detection step. This makes it possible to recognize which autonomous storage device has a large load. Therefore, in the network load balancing method, in the overload determination step, it is determined which autonomous storage device is overloaded based on the load state and a predetermined threshold value. Then, the network load distribution method includes the original content stored in the content storage means of the autonomous storage device that is determined to be overloaded in the access prohibition step, and the other autonomous storage device corresponding to the original content. Access to the backup content stored in the content storage means is prohibited. The network load balancing method changes the roles of the original content and the backup content that are prohibited from being accessed in the role changing step. After this role change, the prohibition of access to the original content and the backup content is canceled in the access cancellation step. As a result, the load on the autonomous storage device whose role is changed to the backup content is distributed to the autonomous storage device whose role is changed to the original content.

  According to the invention of claim 1, claim 4, claim 5 or claim 6, the role of the content stored in the autonomous storage device is changed from the original content to the backup content, and the original content is supported. The load can be distributed only by changing the role of the backup content stored in the other autonomous storage device to the original content. At this time, since the autonomous storage device does not perform operations such as copying content to another autonomous storage device or moving the content within the autonomous storage device, it does not place a load on the network or the like. As a result, it is possible to prevent a decrease in the throughput for the content. Furthermore, according to the present invention, there is no content capacity bias at the time of load distribution, so that the capacity of the content storage means of each autonomous storage apparatus can be utilized to the maximum.

  According to the invention described in claim 2, since the original content is stored in the logically continuous autonomous storage device in the arrangement order indicating the order of the file names and the like, it is possible to easily search for the content. . According to the present invention, since the original content and the backup content are identified based on the role information, the roles of the original content and the backup content can be changed only by changing the role information. . As a result, the autonomous storage device can prevent a decrease in throughput without load of content during load distribution.

  According to the third aspect of the present invention, when the load is distributed, the first or last original content in the arrangement order is changed to the backup content. Therefore, in the logically continuous autonomous storage device, the original content is a file name or the like. The state stored according to the arrangement order indicating the order can be maintained.

  In the following, first, the operation concept of the autonomous storage system that realizes the load balancing method in the present invention will be described, and then the configuration and detailed operation of the autonomous storage device that constitutes the autonomous storage system will be sequentially described. And

[Operational concept of autonomous storage system]
First, the operation concept of the autonomous storage system that implements the load balancing technique will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing a schematic configuration of an autonomous storage system. As shown in FIG. 1, the autonomous storage system 1 includes a plurality (four as an example) of autonomous storage devices 2 (2 ₁ to 2 ₄ ) connected to a network N. The autonomous storage system 1 distributes content among the autonomous storage devices 2 (2 ₁ to 2 ₄ ) when a content write request is received from a client computer 5 or the like connected to the same network N. It is something to remember.

  Here, the autonomous storage device 2 includes a system management unit 20 and a content storage unit 30 (details will be described later), and the system management unit 20 cooperates with other autonomous storage devices. The content is stored in the content storage means 30 so as to distribute the load.

This autonomous storage device 2 stores the original content of content (hereinafter referred to as primary content) and its backup content (hereinafter referred to as backup content) stored in another autonomous storage device in its own content storage means 30. is doing. Here, the autonomous storage device 2 stores the backup content in the autonomous storage devices 2 that are logically adjacent to each other. The autonomous storage device adjacent to the logically last autonomous storage device (here, the autonomous storage device 2 ₄ ) is logically the previous autonomous storage device (here, the autonomous storage device 2 ₃ ), Logically the first autonomous storage device (here, the autonomous storage device 2 ₁ ).

For example, as shown in FIG. 1, when the autonomous storage device 2 _first content storage unit 30 primary content C1 and C2 to ₁ is stored, backed up content C'1 primary content C1 is autonomous storage system 2 ₁ the autonomous storage apparatus 2 ₄ logically contiguous to, also, back up the content C'2 primary content C2 is the autonomous storage unit 2 ₂ which logically adjacent to the autonomous storage device 2 _1, are respectively stored.
Hereinafter, a content storage method and a load distribution method of each autonomous storage apparatus 2 in the operation concept of the autonomous storage system 1 will be described.

(Content storage method)
First, a content storage method in an autonomous storage system including a plurality of autonomous storage apparatuses according to the present invention will be described with reference to FIG. FIG. 3 is a schematic diagram showing an example of a state in which content is distributed and stored in the autonomous storage system, and the autonomous storage device 2 constituting the autonomous storage system 1 (actually the content storage means 30 of the autonomous storage device 2). (See FIG. 1) shows a state in which the content is stored. Here, as an example, the number of autonomous storage apparatuses 2 is four and the number of contents is 16, but the present invention is not limited to this number.

  As shown in FIG. 3, the autonomous storage system 1 does not distinguish the content storage means 30 (see FIG. 1) of the autonomous storage device 2 into a primary area and a backup area as in the conventional case, but makes it the same area. The content is stored in association with information (role information) indicating whether the content is the primary content Cn or the backup content C′n.

The autonomous storage device 2 is set with identification information (identifier) for uniquely specifying the logical adjacency, and the logical number of the first autonomous storage device is 2 ₁ , and the number of the second autonomous storage device is 2 ₂ , the third autonomous storage device is 2 ₃ , and the fourth (last) autonomous storage device is 2 ₄ . In addition, uniquely identified identification information (for example, a file name, a number, etc.) having a logical magnitude relationship is set in the content, and the content having the smallest identification information is the C1, 2nd. The content having the smallest identification information is C2, and similarly, the content having the 16th smallest (largest) identification information is C16.

Here, the autonomous storage device 2 _1, stores the primary content C1 -C4, the autonomous storage devices 2 _2, stores the primary content C₅-C₈, the autonomous storage device 2 ₃ is the primary content C9~C12 storing, in the autonomous storage apparatus 2 _4, stores a primary content C13～C16.

Moreover, the autonomous storage device 2 _1, as logically adjacent backup autonomous storage devices 2 ₂ and 2 ₄ primary content C5, C6, C15 and C16, the backup content C'5, C'6, C'15 And C'16 are stored. Similarly, the autonomous storage devices 2 _2, backup content C'3, C'4, a C'9 and C'10, the autonomous storage system 2 ₃ backup content C'7, C'8, C' 13 and C'14, the autonomous storage apparatus 2 _4, the backup content C'1, C'2, stores C'11 and C'12 respectively.
By storing content in this way, each autonomous storage device 2 becomes a configuration of chained declustering, and even if one of the autonomous storage devices 2 fails and the content is lost, the content is recovered. Can be made.

(Load distribution method)
Next, the load distribution method in the autonomous storage system according to the present invention will be described with reference to FIG. FIG. 4 is an explanatory diagram for explaining an operation when load balancing is performed in the autonomous storage system. Incidentally, FIG. 4, in a storage state of the contents shown in FIG. 3, and concentrated access to the autonomous storage devices 2 _2, when the load of the autonomous storage devices 2 ₂ highest, illustrates how to distribute the load Yes.

In the present invention, the role of the primary content of the autonomous storage device 2 having a large load is changed from primary to backup, and the role of backup content corresponding to the primary content is changed from backup to primary. That is, the load changes the role of the largest autonomous storage system 2 ₂ primary content C5 (FIG. 3), the backup content C'5 a (FIG. 4), the autonomous storage system 2 ₁ backup content C'5 (Figure 3 ) To change to primary content C5 (FIG. 4).
Thus, as shown in FIG. 4, accessible content in the autonomous storage device 2 _1, five of C1 to C5, accessible content in the autonomous storage devices 2 _2, 3 C6~C8 Tsutonari autonomous load of the storage apparatus 2 ₂ will be dispersed in the autonomous storage system 2 _1.

In this way, the content whose role at the time of load distribution is changed is the content having the smallest logical identification information (identifier) in the primary content of the autonomous storage device 2 having a large load (in FIG. 3). autonomous primary content C5 in the storage apparatus 2 _2), or with any of the logically highest identity (content having an identifier) (primary content C8 in autonomous storage system 2 ₂ of FIG. 3).
As a result, as shown in FIG. 4, the primary content is maintained in continuity (C1 to C16) across the autonomous storage apparatuses 2, and the content can be easily searched.
Here, the role of primary contents has been described as changing from primary to backup one by one, but the roles of a plurality of primary contents may be changed to backup collectively.

[Configuration of autonomous storage system]
Next, a configuration of the autonomous storage apparatus according to the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the autonomous storage apparatus.
As shown in FIG. 2, the autonomous storage apparatus 2 is connected to a network N and stores contents in a distributed manner in cooperation with other autonomous storage apparatuses. Here, the autonomous storage apparatus 2 includes a communication transmitting / receiving unit 10, a system management unit 20, a content storage unit 30, and an index information storage unit 40.

  The communication transmitting / receiving means 10 transmits / receives data to / from a client computer (not shown) and other autonomous storage devices (not shown) via the network N. For example, the communication transmitting / receiving means 10 is a communication board that transmits and receives data using a TCP / IP (Transmission Control Protocol / Internet Protocol) communication protocol.

  The system management means 20 controls the entire autonomous storage apparatus 2. For example, the system management unit 20 is a computer having a CPU (Central Processing Unit), a memory, and the like, and by causing the program to function as each unit shown below, Dispersion. Here, the system management unit 20 includes a content storage unit 21, a content distribution unit 22, a content deletion unit 23, a control information reception unit 24, a control information transmission unit 25, and a content management unit 26. .

  The content storage unit 21 acquires content via the communication transmitting / receiving unit 10 and stores it in the content storage unit 30. The content storage unit 21 includes a content receiving unit 21a and a content writing unit 21b.

  The content receiving unit 21 a receives the content acquired via the communication transmitting / receiving unit 10. The content receiving unit 21 a receives content from the content transmission source (for example, a client computer, another autonomous storage device, etc.) notified from the content operation control unit 262 of the content management unit 26 via the communication transmitting / receiving unit 10. To do. The content received here is output to the content writing means 21b.

  The content writing unit 21b writes the content received by the content receiving unit 21a into the content storage unit 30 as the primary content 30a or the backup content 30b of the content storage unit 30. The content writing unit 21 b writes the content in the content storage unit 30 based on the position information (address) notified from the content operation control unit 262 of the content management unit 26. The content management unit 26 manages whether the content written in the content storage unit 30 is the primary content 30a or the backup content 30b.

  The content distribution unit 22 distributes the content (primary content 30a or backup content 30b) stored in the content storage unit 30 via the communication transmitting / receiving unit 10, and includes a content reading unit 22a and a content transmission unit 22b. It has.

  The content reading unit 22a reads the content (primary content 30a or backup content 30b) stored in the content storage unit 30. The content reading unit 22 a reads the content from the content storage unit 30 based on the position information (address) notified from the content operation control unit 262 of the content management unit 26. The content read here is output to the content transmission means 22b.

  The content transmitting unit 22b transmits the content read by the content reading unit 22a via the communication transmitting / receiving unit 10. The content transmission unit 22b transmits the content via the communication transmission / reception unit 10 to the transmission destination of the content notified from the content operation control unit 262 of the content management unit 26 (for example, a client computer, another autonomous storage device, etc.). To do.

  The content deletion unit 23 deletes the content (primary content 30a or backup content 30b) stored in the content storage unit 30. The content deletion unit 23 deletes the instructed content from the content storage unit 30 based on the position information (address) notified from the content operation control unit 262 of the content management unit 26.

  The control information receiving unit 24 receives control information that is data other than content from a client computer, another autonomous storage device, or the like via the communication transmitting / receiving unit 10. The control information received here is output to the control information analysis unit 261 of the content management unit 26.

  Here, the control information is information for the autonomous storage device 2 to operate in cooperation with other autonomous storage devices. For example, a content storage instruction indicating that content is stored, a content distribution instruction indicating that content is distributed, a content deletion instruction indicating that content is to be deleted, a load status notification instruction that indicates a load status notification, and access to content For example, an access control instruction indicating prohibition or release thereof, a role change instruction indicating that the role of content is to be changed, or a response to these instructions.

  The control information transmission unit 25 transmits the control information output from the content management unit 26 to the client computer, another autonomous storage device, or the like via the communication transmission / reception unit 10.

The content management unit 26 manages content based on the control information received by the control information receiving unit 24. Note that the content management unit 26 also changes the role of content from primary content to backup content when the load state of the autonomous storage device 2 increases.
Here, the content management unit 26 includes a control information analysis unit 261, a content operation control unit 262, and a role change unit 263.

The control information analyzing unit 261 analyzes the control information received by the control information receiving unit 24 and executes a process corresponding to the control information. For example, when a content storage instruction, a content distribution instruction, or a content deletion instruction is instructed as control information, the control information analysis unit 261 outputs the fact to the content operation control unit 262. Further, when a role change instruction is instructed as control information, the fact is output to the role change means 263.
Further, here, the control information analysis unit 261 includes a load state detection unit 261a and an access control unit 261b.

The load state detection unit 261a detects the load state of the autonomous storage device 2 and the load state of other autonomous storage devices. For example, the load state detection unit 261a detects its own load state based on the number of accesses to the content per unit time. Further, the load state detection unit 261a acquires the load state of the other autonomous storage device from the other autonomous storage device as control information. Thereby, the load state detection unit 261a can grasp the load states of all the autonomous storage apparatuses 2 connected to the network N.
In this case, it is assumed that the autonomous storage apparatus having the largest load state value and larger than a predetermined threshold changes the role of the content in a lead manner.

  The access control unit 261b prohibits (locks) or releases access (reading and writing) to the content stored in the content storage unit 30. When changing the role of content, the access control means 261b prohibits access to the content (primary content 30a or backup content 30b) to be changed. Further, the access control unit 261b cancels the prohibition of access to the content after updating the role of the content.

  The content operation control means 262 operates content based on various instructions output from the control information analysis means 261. When the content operation control unit 262 is instructed to store the content from the control information analysis unit 261, the content operation control unit 262 instructs the content storage unit 21 to transmit the content and the position information (address) stored in the content storage unit 30. Is stored (stored). Further, when the content operation control unit 262 is instructed by the control information analysis unit 261 to send a content distribution instruction, the content operation control unit 262 gives the content distribution unit 22 the content destination and the location information (address) of the content storage unit 30. The content is distributed by notifying. Furthermore, when the content operation control unit 262 is instructed by the control information analysis unit 261 to delete the content, the content operation control unit 262 notifies the content deletion unit 23 of the location information (address) of the content storage unit 30 to delete the content. I do.

  When the content operation control unit 262 stores content (primary content 30a or backup content 30b) in the content storage unit 30, the identification information 40a, association information 40b, role information 40c, and position information 40d of the index information storage unit 40 are stored. Update. The contents of the various information will be described later.

  The role changing unit 263 is notified of an instruction to change the role of the content from the control information analyzing unit 261, so that the content stored in the content storage unit 30 and other content associated with this content are displayed. The role of the content of the autonomous storage device is changed. Then, the role change unit 263 updates the role information 40c in the index information storage unit 40.

That is, when the role changing unit 263 receives an instruction from the control information analyzing unit 261 to change the role of the content, if the content is the primary content 30a, the role changing unit 263 changes the content to the backup content 30b. At the same time, the association information 40b transmits to the autonomous storage device 2 associated with the association information 40b an instruction to change the content of the other autonomous storage device associated with the content from the backup content to the primary content. .
Conversely, when the content is the backup content 30b, the content is changed to the primary content 30a.

  The content storage means 30 stores primary content 30a that is original content and backup content 30b that is a backup of the original content stored in another autonomous storage device, and is a general storage device such as a hard disk. . The content storage means 30 stores the content without dividing the area for storing the primary content 30a and the backup content 30b. Here, whether the content is the primary content 30a or the backup content 30b is distinguished by role information 40c corresponding to the content specified by the identification information 40a stored in the index information storage means 40.

  As shown in FIG. 3, the autonomous storage device 2 stores the primary content 30 a in the content storage unit 30 so that the identification information 40 a that is the content arrangement order is continuous in each autonomous storage device. For example, when a file name is used as identification information, the content arrangement order is determined in alphabetical order, alphabetical order, or the like. In addition, the autonomous storage device 2 is a content stored in the content storage unit 30 of another autonomous storage device that is continuous at least before or after in the arrangement order of the primary content (original content) stored in the content storage unit 30. The backup of (primary content) is stored as the backup content 30b.

  The index information storage means (role information storage means, association information storage means) 40 stores index information that is information for specifying the content (primary content 30a or backup content 30b) stored in the content storage means 30. It is a general storage device such as a hard disk. The index information storage means 40 stores identification information 40a, association information 40b, role information 40c, and position information 40d as index information.

  Here, the identification information 40a is information for uniquely specifying the content, and is, for example, a file name, a number, or the like. The association information 40b is information for associating the content stored in the autonomous storage device 2 with the content stored in another autonomous storage device, and the content stored in the autonomous storage device 2 is primary. In the case of content, the information indicates the position of the backup content, and in the case where the content stored in the autonomous storage device 2 is the backup content, the information indicates the position of the primary content. The role information 40c is information indicating the role of the content as primary content or backup content. Further, the position information 40d indicates the address on the content storage means 30 of the content (primary content 30a or backup content 30b).

  By configuring the autonomous storage device 2 in this way, when the load on the autonomous storage device 2 becomes large, the content stored in the autonomous storage device 2 is coordinated with other autonomous storage devices 2 The role can be changed from primary content to backup content. As a result, load distribution can be performed without copying or moving content.

  Moreover, since the number of contents does not change due to this load distribution, there is no bias in the data amount of contents stored in each autonomous storage device 2. As a result, the capacity of each content storage means 30 can be utilized to the maximum as the entire autonomous storage system 1 (see FIG. 1) composed of a plurality of autonomous storage devices 2.

  The system management means 20 of the autonomous storage device 2 can be realized by causing a general computer to execute a program and operating a computing device or a storage device in the computer. The program for distributing the load via the network (network load distribution program) realized here can be distributed via a communication line, or can be written and distributed on a recording medium such as a CD-ROM. Is possible.

[Operation of autonomous storage system]
Next, the operation of the autonomous storage apparatus will be described with reference to FIG. 5 (refer to FIG. 2 as appropriate). Here, an operation in which the autonomous storage apparatus according to the present invention distributes a load via a network in cooperation with another autonomous storage apparatus will be described. FIG. 5 is a flowchart showing the load balancing operation in the autonomous storage system including the autonomous storage apparatus according to the present invention. In FIG. 5, it is assumed that the load in the autonomous storage system 2 ₂ are concentrated, to change to a backup content the role of the content stored in the autonomous storage system 2 ₂ from the primary content, the backup of the content shows an operation to change the backup contents autonomous storage system 2 ₁ stored in the primary content.

(Load status detection / overload judgment step)
First, the autonomous storage device 2 ₂ detects the load state in the autonomous storage device 2 ₂ from the number of accesses to the content per unit time by the load state detection unit 261a of the content management unit 26, and sets it to a predetermined threshold value. based on, it determines whether the load state of the autonomous storage device 2 ₂ is overloaded (step S1).
In this case, in other autonomous storage devices (here, in the autonomous storage device 2 _1, likewise loaded condition is detected, the determination (step S1 '), among the autonomous storage devices, to check the load state on each other. Then, the autonomous storage device 2 ₂ executes the operations after step S2 when the load state of the autonomous storage device 2 ₂ is overload.

(Operation completion waiting step)
Autonomous storage system 2 _2, the role change means 263, determines the content to be role change (step S2). Here, in the primary content 30a stored in the content storage unit 30, the role changing unit 263 corresponds to the content in the primary content 30a in which the identification information 40a that is the content arrangement order is the first or last. The autonomous storage device storing the backup content to be loaded is determined as the content whose role is changed. Here, it is assumed that primary content C5 (backup content C′5) is determined as the content.
Then, the autonomous storage devices 2 _2, the content is determined whether the current operation (during access) (step S3), and waits until the operation is completed (Yes in step S3).

(Access prohibition step)
Furthermore, at the stage where the operation is completed in step S3 (No in step S3), and the autonomous storage device 2 _1, the access control unit 261b, to inhibit access to the primary content C5 (locked) (Step S4).
Moreover, the autonomous storage devices 2 _2, the access control unit 261b, to the autonomous storage system 2 ₂ sends an instruction to prohibit access to backup content C'5, the autonomous storage device 2 _1, backup Access to the content C′5 is prohibited (step S5).

(Role change step)
Then, at the stage access to backup content C'5 is prohibited, the autonomous storage devices 2 _2, the role change means 263, the role of the primary content C5, change the backup, the backup content C'5 ( Step S6). The role change means 263, to the autonomous storage system 2 ₁ transmits an instruction to change the role of backup content C'5, the autonomous storage device 2 _1, the role of backup content C'5, The primary content is changed to the primary content C5 (step S7).

(Access release step)
Moreover, the autonomous storage system 2 ₂ after role change of contents in step S6 and step S7, the access control unit 261b, releases the prohibition of access to the backup contents C'5 (step S8), and the autonomous storage system 2 ₁ In response to this, an instruction to cancel the prohibition of access to the primary content C5 is transmitted.
Then, the autonomous storage device 2 _1, prohibition of access to the primary content C5 is released (step S9).

  With the above operation, the autonomous storage device 2 can change the primary content of the autonomous storage device having a large load to backup content in cooperation with other autonomous storage devices. As a result, the load is distributed to other autonomous storage apparatuses.

1 is a schematic configuration diagram showing a schematic configuration of an autonomous storage system according to the present invention. It is a block block diagram which shows the structure of the autonomous storage apparatus which concerns on this invention. It is a schematic diagram which shows an example of the state which distributed and memorize | stored the content in the autonomous storage system which concerns on this invention. It is explanatory drawing for demonstrating the operation | movement at the time of performing load distribution in the autonomous storage system which concerns on this invention. It is a flowchart which shows the operation | movement of load distribution in the autonomous storage system which concerns on this invention. It is a schematic diagram which shows an example of the state which distributed and memorize | stored the content in the conventional autonomous storage system. It is a flowchart which shows the operation | movement of load distribution in the conventional autonomous storage system. It is a schematic diagram which shows the memory | storage state of the content after the load distribution operation | movement in the conventional autonomous storage system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Autonomous storage system 2 Autonomous storage apparatus 10 Communication transmission / reception means 20 System management means 21 Content storage means 22 Content distribution means 23 Content deletion means 24 Control information reception means 25 Control information transmission means 26 Content management means 261 Control information analysis means 261a Load state Detection means 261b Access control means 262 Content operation control means 263 Role change means 30 Content storage means 40 Index information storage means (role information storage means, association information storage means)

Claims (6)

In an autonomous storage device that is connected to a plurality of networks and distributes and stores content as original content and backup content,
Content storage means for storing original content stored in the autonomous storage device and backup content for the original content stored in another autonomous storage device connected to the network;
Role information storage means for storing role information indicating whether the content is original content or backup content for each content stored in the content storage means;
Association information for storing association information indicating the association between the original content and the backup content in the content and the content stored in the content storage unit of the other autonomous storage device for each content stored in the content storage unit Storage means;
Load state detection means for detecting load states of the autonomous storage device and the other autonomous storage device based on access to the content;
Based on the load state detected by the load state detection means, the role stored in the content storage means and the role associated with the content and the content associated with the association information are changed, and the role information Role changing means for updating
Content operation control means for performing operations on the original content based on role information stored in the role information storage means;
An autonomous storage device comprising:   The content storage means stores the original content associated with the identification information indicating the arrangement order and a backup corresponding to the original content that is stored in the content storage means of another autonomous storage device and continues before or after the arrangement order. 2. The autonomous storage apparatus according to claim 1, wherein content is stored.   When the load state detected by the load state detection unit is an overload state, the role changing unit is the first or last in the arrangement order among the original contents stored in the content storage unit. The role of the original content or the original content group that is continuous with the first or last original content in the arrangement order is changed to the backup content, and the corresponding backup content group is changed to the original content. The autonomous storage apparatus according to claim 2. An autonomous storage system that stores content in a distributed manner as original content and backup content,
A plurality of autonomous storage devices according to any one of claims 1 to 3, connected to a network,
Among the plurality of autonomous storage devices, the original content stored in the content storage unit of the autonomous storage device in an overloaded state and the content storage unit of another autonomous storage device corresponding to the original content are stored. An autonomous storage system characterized by changing the role of backup content. In order to distribute the load of an autonomous storage device that includes content storage means for storing content and is connected to a network to distribute and store the content as original content and backup content, a computer in the autonomous storage device is provided. ,
Load state detection means for detecting load states of the autonomous storage device and other autonomous storage devices based on access to the content in the network;
Based on the load state detected by the load state detection unit, the content stored in the content storage unit of the autonomous storage device and the content stored in the content storage unit of the other autonomous storage device, Role changing means for changing role information indicating a role as original content or backup content and storing it in role information storage means,
Content operation control means for performing an operation on the original content based on the role information stored in the role information storage means;
Network load balancing program characterized by functioning as Load balancing among the autonomous storage devices in an autonomous storage system that stores and distributes the content as original content and backup content by connecting a plurality of autonomous storage devices equipped with content storage means for storing content to a network A network load balancing method for performing
A load state detection step of detecting a load state of the autonomous storage device based on access to the content in the network;
An overload determination step of determining whether the autonomous storage device is overloaded based on the load state detected in the load state detection step and a predetermined threshold;
The original content stored in the content storage means of the autonomous storage apparatus determined to be overloaded in this overload determination step, and stored in the content storage means of another autonomous storage apparatus corresponding to the original content An access prohibition step for prohibiting access to the backup content that is present,
A role changing step for changing the roles of the original content and the backup content whose access is prohibited in the access prohibiting step;
An access release step for releasing the prohibition of access to the original content and the backup content whose role has been changed in this role change step;
A network load balancing method comprising:

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