JP2002183019A - Cache device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cache device which can conceal the access time of a network when contents are accessed and receive the contents without being affected by the congestion of the network. SOLUTION: Contents transmitted from a contents provision side are received by a contents reception part 111 and a contents manager 112 determines whether the contents are stored according to meta information showing the attributes of the contents and a user profile 117 showing the access tendency of a user, stores the contents whose storage is decided in a file system 117, and generates and holes index information showing the contents in a contents list 115.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cache device for selecting contents distributed via a network based on a user's taste and preference and meta information of the contents, holding the selected contents, and providing the contents to the user. It is.

[0002]

2. Description of the Related Art Conventionally, when receiving multimedia contents via a network such as the Internet and trying to view them on a terminal, a user searches for a server that holds the contents that the user wants to view. U of server
In general, a method of specifying an RL (User Resource Locator), a method of registering a URL in a channel of reproduction software in advance, and selecting a channel to obtain a target content are used.

[0003] In such a system, in order to obtain data that the user of the terminal really wants to see, it is necessary to perform a search many times using a method such as performing a search using a keyword, and then perform a necessary search. A step of registering the URL of the server having the data was required, which was extremely troublesome and time-consuming.

[0004]

SUMMARY OF THE INVENTION Such a problem is caused by a means for distributing a large amount of contents to a large number of viewers at the same time as compared with a highly interactive network such as the Internet, such as a broadcast system using satellite communication. By using the content distribution, the trouble of searching can be reduced, and the time for acquiring the content can be reduced. However, in such a system, since each user cannot select the content to be distributed, there is a problem that a large amount of transmitted content wastes a data storage device such as a user's disk. Recently, PICS (Platfo
rm for Internet Content Selection) and RD-F (Res
There is also a system that selectively receives necessary information using data describing meta information about the content using ource Description Framework) .However, such meta information is used to select necessary data. In many cases, it is used as an auxiliary means of search, and is not yet fully utilized for the purpose of selectively acquiring content according to a user's profile.

The present invention has been made in view of the above circumstances, and has as its object to receive meta information together with contents and store the meta information in a cache as temporary storage means by setting meta information and a user profile. Provided is a cache device that conceals the network access time at the time of content access by judging and storing the content to be accessed, and can receive the content without being affected by network congestion. This also provides a system capable of quickly and efficiently distributing and browsing contents.

[0006]

In order to achieve the above object, a cache device of the present invention holds content provided from a content providing side, and stores the content held by the user at the request of the user. A cache device that receives a content transmitted from the content providing side and determines whether to store the content based on meta information indicating an attribute of the content and a user profile set by the user And a data holding means for holding the content determined to be stored by the reception determining means, and a content management means for generating index information indicating the content of the content and holding the index information in a content list. .

In the present invention, preferably, the content management means determines the priority of the received content based on the user profile, and stores the priority in the content list.

[0008] In the present invention, preferably, the content management means, when the user requests a content for which category information is specified, based on the category information and the content list, The held content is selected, and the selected content is provided to the user.

In the present invention, preferably, the content management means inspects the content list at a predetermined timing. In this inspection, for example, the priority of the content described in the content list is updated based on the priority information of the user profile. Further, it is determined whether to save or delete the content based on the priority information and the access information of the content.

In the present invention, preferably, the content management means selects the held content when the capacity of the content held in the data holding means reaches a predetermined reference value. To delete. For example,
The content management means selects content to be deleted based on the priority of the content stored in the content list. Further, the content to be deleted is selected based on the last access time information of the content stored in the content list.

In the present invention, preferably, the user profile includes information indicating the access tendency of the user, and the content management means sets the item of the user profile according to the access tendency of the user. Change.

In the present invention, preferably, the content management means updates an access counter value indicating the number of times the content is accessed in the content list when providing the content to a user.

In the present invention, preferably, the content management means further divides the category information of the content having the largest access counter value.

Further, in the present invention, preferably, the content management means selects a data holding means for holding the content based on the priority of the received content. In this case, for example, the high-priority content is held in a more reliable data holding unit.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a block diagram showing an example of a network system including a cache device according to the present invention. As illustrated, the cache device 101 is connected to a network 106 and a network 105, respectively. Here, the network 105 is a wide area network such as the Internet, and the network 106 is a LAN (Local Area
Network).

The network 105 is connected to a content distribution server 104 managed by a content provider that distributes content. In addition, a general RTSP (RealTime Strea
ming Protocol) server 102, HTTP (HyperText)
Transfer Protocol) Many servers 103 are connected. A client computer 107 used in a LAN environment is connected to the network 106.

The cache device 101 includes a content receiving unit 111, a content manager 112, an RTSP
Proxy server 113, HTTP proxy server 11
4. Content list 115, file system 116
And a user profile 117 are included.

The content receiving unit 111 of the cache device 101 is connected to the network 105 via a network interface,
4 is received. Cache device 1
The RTSP proxy server 113 connected to the network 106 and the network 105 via the network interface, responds to the RTSP request from the client computer 107, and receives the RTSP server 102 connected to the network 105.
Relays the request to

The HTTP proxy server 114 of the cache device 101 is connected to the network 106 and the network 105 via a network interface.
It responds to the request and relays the request to the HTTP server 103 connected to the network 105.

The content manager 112 of the cache device 101 is connected to each of the other modules in the cache device 101. First, the content manager 112 is connected to the content receiving unit 111 and receives data received by the content receiving unit. Also connected to the RTSP proxy server 113, the RTS
Upon receiving the content request from the P proxy server 113, the content search processing is performed, and the content of the search result or the notification of the search failure is returned. The content manager 112 is connected to the content list 115,
The content information is added to the content list 115, the content information is changed, the content information is searched, and the like. Further, it is connected to the file system 116 and performs writing, reading, and deleting of contents by designating a file name. Also, the user profile 117
To read and change the user profile.

The content list 115 is connected to the content manager 112, and internally stores a URL as a content name, a priority as an integer value corresponding to the content, and a file name indicating a storage location of the content in the file system 116. One piece of content index information is stored for each piece of content index information including the last access date and time that is the date and time when the request for the content was last received. FIG. 2 shows an example of the content list.

The file system 116 is constituted by a data storage device for storing the content data received by the content receiving section 111. For content determined to be received by the content manager 112, content index information is generated and stored in the content list 115, and the content of the content is stored in the file system.

The user profile 117 is connected to the content manager 112 and holds therein category information which is information on categories for classifying contents therein. The category information is subcategory information including a column of a category name, a priority that is an integer value corresponding to the category, an access counter that is the number of times a request for one content is received, and a category name that further categorizes the category. , One for each category. FIG. 3 shows an example of the user profile.

Hereinafter, the cache device 101 of this embodiment will be described.
The operations at the time of content reception, content reproduction, content check, content deletion, and user profile check will be described.

Operation at Content Reception FIG. 4 shows an operation sequence when the content is distributed from the content distribution provider 104 to the cache device 101 and the reception is successful. Hereinafter, with reference to FIG.
The operation at the time of content reception will be described.

Step S1: Content distribution server 10
4, the content is transmitted to the push-type cache device 101. In the cache device 101, the distributed content is received by the content receiving unit 111.

Step S2: Content receiving section 111
Transmits the received content to the content manager 1
Hand over to 12. The content manager 112 obtains the meta information of the received content, analyzes the meta information, and extracts information on the content category from the meta information. The acquisition of the meta information is performed, for example, by using XML (Extensible Mx) for the data of the MPEG format.
(e.g., arkup language), meta information is added to the beginning of the data at the time of transmission, and the data is transmitted. Also, URIs are not included in the format of content.
For example, a method is also possible in which an identifier for meta information is included, and the content manager 112 issues an acquisition request to the network using the identifier.

Step S3: Content Manager 1
Reference numeral 12 performs information search from the user profile 117 based on the category information extracted from the meta information. Step S4: Through this search, the priority set by the user corresponding to the category of the content is acquired, and this is set as the priority of the received content.

Step S5: Content Manager 1
12 determines whether to receive the content based on the priority of the content obtained by the search. When the priority satisfies a predetermined condition, for example, when the integer value indicating the priority is larger than 0, the reception of the content is determined.

Step S6: Content Manager 1
12 transmits the data of the content determined to be received to the file system 116. Content data is held by the file system 116.

Step S7: Content Manager 1
12 generates content index information based on the content and registers the content index information in the content list 115. Step S8: After registering the content index information in accordance with the registration instruction of the content manager 112, the content list 115
Then, the registered response is transmitted to.

The content manager 1 described above
12, if the priority of the content is 0, it is regarded as a normal priority, the content is stored as a data file in the content storage area of the file system 116, and the name, category, and priority of the content are stored in the content list 115. Each time, content index information consisting of a file name is added.

If the priority of the content is 1 or more, the file system 1
The content is stored in the content storage area 16 and content index information including the name, category, priority, and file name of the content is added to the content list 115.

In the example described here, the priority value corresponding to the content category set in the user profile 117 is used as it is as the content priority, but in general, the priority of the content is: This is a function calculated from zero or more meta information parameters and zero or more user profile setting items.

FIG. 5 shows a content distribution provider 104.
FIG. 7 is a sequence diagram showing an operation when the cache device 101 refuses reception of content distributed by the cache device 101.

As shown, in this case, the processing from steps S1 to S5 is the same as the reception processing shown in FIG.
In the content acquisition determination in step S5, if the priority of the content is 0 or a positive number, the content is received. Conversely, if the priority of the content is smaller than 0,
That is, if the integer indicating the priority is negative, the reception of the content is rejected.

Operation at Content Reproduction A client for content reproduction, for example, the RTSP client 121 or the HTTP client 122 in the client computer 107 is
FIG. 6 shows a sequence of an operation when the content is received via the PC 1 and the content is reproduced. Hereinafter, the operation at the time of content reproduction will be described with reference to FIG.

Step SS1: Here, for example, a content playback request is transmitted from the content playback RTSP client 121 to the RTSP proxy server 113 of the cache device 101.

Step SS2: The RTSP proxy server 113 analyzes the received request, extracts the name of the content from the received request, passes it to the content manager 112, and requests the content.

Step SS3: The content manager 112 issues a search request to the content list 115 using the specified content. Step SS4: The content list 115 transmits the found file name to the content manager 112.

Step SS5: The content manager 112 passes the file name to the file system 116 and requests data reading. Step SS6: The file system 116 reads data from the storage location of the designated file name and passes it to the content manager 112.

Step SS7: The contents manager 112 transmits the contents data to the RTSP proxy 113.
Pass to. Step SS8: The RTSP proxy 113 transmits the content data to the RTSP client 102.

Step SS9: The content manager 112 instructs the content list 115 to update the access date. Step SS10: The content list 115 updates the access date in the content index information according to the instruction of the content manager 112, and sends an updated response to the content manager 112.

Step SS11: The content manager 112 acquires the category information of the specified content category from the user profile 117, increases the value of the access counter therein by one, and reflects the change in the user profile. Step SS12: The user profile 117 transmits to the content manager 112 a response in which the value of the access counter has been updated.

If the specified content does not exist in the content list 115, the content is notified to the RTSP proxy server 113. The RTSP proxy server 113 communicates with the network 105 specified by the request.
Sends a request to the RTSP server 102 connected to the server, receives a response, and relays the RTSP session.

Operation at the time of content check The content manager examines the content of the content list 115 by any event, such as receiving a signal from a timer notifying that a predetermined time has elapsed or an RTSP request, and performs processing for changing the content. .
Hereinafter, the operation at the time of checking the content list will be described.

First, information relating to one content is extracted from the content list 115, and the following operation is performed. If the value of the deletion judgment function, which is a function of the last access date and time of the content and the priority, is 0 or less,
The content data is deleted from the file system 116, and the index information corresponding to the content is deleted from the content list 115.

Here, as the erasure determination function, for example,
A function such as ((priority × constant A) + constant B) − (current time−last access date and time) can be considered.

Next, the priority of the user profile 115 corresponding to the content category is checked, and if the priority is different from the value of the priority in the content index information, the value of the priority of the content index information is updated. In the case of the operation by the timer, the above operation is performed on all the contents included in the content list 115.

Operation at the time of content deletion The content manager 112 outputs a signal from a timer notifying that a predetermined time has elapsed, or an RTSP.
The content is deleted by some event such as receiving a request.

For example, the content manager 112
Obtains the total capacity of the content data held in the file system 117 at the time of receiving the content, and compares it with the total capacity of the file system 117.

If the total capacity of the content / the total capacity of the file system is equal to or more than a certain value, the content index information of the oldest last access date and time is acquired from the content list 117.

Next, if the priority of the content is 0 according to the obtained index information of the content, the content is deleted. On the other hand, if the priority of the content is 1 or more, the content information is not deleted, but the content information of the next last access date and time is acquired.

With the above operation, the amount of content data to be stored is adjusted according to the storage capacity of the file system 117 and the total capacity of the stored content data. In this case, the content with the lower priority is deleted, and if the priority is the same, the content with the oldest access date and time is deleted. Therefore, the content with the higher priority is stored in the cache device 101 for a longer time. Can be.

Operation When Checking User Profile The content manager 112 examines the contents of the user profile 117 at regular time intervals and makes changes.
First, an access counter value corresponding to each category in the category list is checked. The priority of the category with the largest access counter value among all categories is set to 1
The priority of the category having the smallest access counter value among all the categories is decreased by one.

The embodiments of the present invention are not limited to those described here. For example, the RTSP server 1
02 and RTSP proxy server 113, and also RTS
In addition to the P client 121, the HTTP server 10
3. It is also possible to adopt a configuration in which the HTTP proxy server 114 and the HTTP client 122 operate simultaneously.

As described above, according to the present embodiment, the content acquisition time can be reduced, the content can be distributed effectively using the network bandwidth, and the content belonging to a category that is unlikely to be used by the user can be obtained. By using a mechanism that does not receive content or a mechanism that stores content belonging to a category desired by the user longer than general content, it is possible to realize a content distribution system that can efficiently store content in a cache device.

Second Embodiment In the cache device of the present embodiment, the other components are almost the same as those of the first embodiment except for the configuration of the user profile 117. In the present embodiment, the user profile 117 is connected to the content manager 112, and internally stores category information for classifying content. Furthermore, the user manager 11
Category information can be newly added in accordance with the instruction 2.

Hereinafter, the operation at the time of checking the user profile 117, which is different from the first embodiment, will be described.

Operation When Checking User Profile The content manager 112 checks the contents of the user profile 117 at regular time intervals, and when making a change, checks the access counter value corresponding to each category in the category list. For the category having the largest access counter value among all the categories, the content provider requests the content provider to further categorize the category.

For example, for the category of “sports: motor sports” having the largest access counter value in FIG. 3, a sub-category is requested from a content provider or another category provider, and the category name of the sub-category is received. User profile 11
7, new category information is added.

At this time, since the priority of the newly added category information and the value of the access counter are not determined, the priority of the category information can be copied from the value of the upper category. Furthermore, the value of the access counter is obtained by dividing the value of the upper category by an appropriate guess, or by acquiring hint information for division at the time of receiving the category information and applying it. The priority and the value of the access counter are set to the newly added category, and at the same time, the previous access counter value of the upper category is changed.

For example, the user profile 117 shown in FIG.
From the state, "Sports: Motorsports: Rally"
And "Sports: Motorsports: F1", a new user profile shown in FIG. 7 is generated by determining the priority of the category information and the value of the access counter and adding them to the user profile.

When a category is added, in order to prevent the size of the category list from becoming too large, even if a category which is a sub-category of a category having the smallest access counter value among all the categories is removed. Good.

As described above, according to the present embodiment, among the setting items of the user profile 117, it is possible to make more detailed settings for items that are more necessary for the user, thereby improving convenience. I do.

Third Embodiment The cache device according to the third embodiment is the same as the first embodiment except for the operation at the time of receiving the content. Hereinafter, the operation of the cache device according to the present embodiment when receiving content will be mainly described.

Operation upon Receiving Content The content manager 112 determines the priority of the content with respect to the content received from the content distribution provider, and selects the processing method of the content in accordance with the priority of the content. Is 1
If it is the above, the content is stored as a high priority content in the priority content storage area of the file system, and content information including the content name, category, priority, and file name is added to the priority content list.

The priority content storage area of the file system is an area where data can be read out earlier than other areas, or an area where the risk of data loss is lower.
For example, when the file system is composed of a plurality of disk devices, it refers to a higher-performance disk device. By arranging such contents, higher-priority contents can be reliably stored, and high-priority contents can be provided to the user with high reliability.

As described above, according to the present embodiment, it is possible to allocate high-quality hardware resources to contents that are more likely to be used by users, thereby improving service quality and improving resource utilization. Can be effectively used.

[0070]

As described above, according to the cache device of the present invention, the content can be efficiently stored on the basis of the user profile created according to the user's tastes and preferences, the content distributed by the distribution server, and its meta information. Since the data is temporarily filtered and can be temporarily stored in the cache device, there is an advantage that network traffic can be reduced and the storage area of the cache device can be used efficiently.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one configuration example of a network system including a cache device according to the present invention.

FIG. 2 is a diagram illustrating a configuration example of a content list.

FIG. 3 is a diagram illustrating a configuration example of a user profile.

FIG. 4 is a sequence diagram showing a process when receiving content.

FIG. 5 is a sequence diagram illustrating a process for rejecting reception of content distributed by the content distribution server.

FIG. 6 is a sequence diagram showing an operation at the time of content reproduction.

FIG. 7 is a diagram illustrating a configuration example of a changed user profile.

[Explanation of symbols]

101: Cache device, 102: RTSP server, 1
03: HTTP server, 104: content distribution server, 105: wide area network, 106: local network, 107: client computer, 111: content receiving unit, 112: content manager, 11
3 RTSP proxy server, 114 HTTP proxy server, 115 content list, 116 file system, 117 user profile, 121 R
TSP client, 122 ... HTTP client.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 17/30 340 G06F 17/30 340A

Claims (15)

[Claims] 1. A cache device for holding content provided from a content providing side and providing the content held by the user in response to a request from the user, wherein the content is transmitted from the content providing side. Receiving determination means for determining whether or not to store the content, based on meta information indicating the attribute of the content and a user profile set by the user; and storing is determined by the reception determining means. Data holding means for holding the content, and index information indicating the content of the content,
A cache device comprising: a content management unit that holds a content list. 2. The cache device according to claim 1, wherein the content management means determines a priority of the received content based on the user profile and stores the priority in the content list. 3. The content management means, when a content specified by category information is requested by the user, selects the content stored in the storage means based on the category information and the content list. 2. The cache device according to claim 1, wherein the selected content is provided to the user. 4. The cache device according to claim 1, wherein said content management means checks said content list at a predetermined timing. 5. The cache device according to claim 4, wherein the content management means updates the priority of the content described in the content list based on the priority information of the user profile in the inspection. 6. The cache device according to claim 4, wherein the content management means determines whether to save or delete the content based on the priority information and access information of the content in the inspection. 7. The content management device according to claim 1, wherein the content management means selects and deletes the held content when the capacity of the content held in the data holding means reaches a predetermined reference value. Cache device. 8. The cache device according to claim 7, wherein said content management means selects content to be deleted based on the priority of said content stored in said content list. 9. The cache device according to claim 7, wherein said content management means selects content to be deleted based on last access time information of said content stored in said content list. 10. The cache device according to claim 1, wherein the user profile includes information indicating an access tendency of the user. 11. The cache device according to claim 1, wherein said content management means changes items of said user profile in accordance with an access tendency of said user. 12. The cache device according to claim 1, wherein the content management means updates an access counter value indicating the number of times the content is accessed in the content list when providing the content to a user. 13. The cache device according to claim 12, wherein said content management means further divides the category information of the content having the largest access counter value. 14. The cache device according to claim 1, wherein said content management means selects a data holding means for holding said content based on a priority of said received content. 15. The cache device according to claim 14, wherein said content management means causes said high-priority content to be held by a more reliable data holding means.