WO2007045736A1

WO2007045736A1 - System and method for providing data

Info

Publication number: WO2007045736A1
Application number: PCT/FR2006/002221
Authority: WO
Inventors: Sébastien Campion; Catherine Guitot; Philippe Roquin
Original assignee: France Telecom
Priority date: 2005-10-18
Filing date: 2006-10-02
Publication date: 2007-04-26

Abstract

The invention concerns a system for providing data derived from a storage device (12) via a communication network (4) and using at least one cache memory (8), the system comprising at least one data manager (10) co-operating with the storage device. The invention is characterized in that the data manager comprises: means (16) for analyzing the content of data derived from the storage device; and means (18) for determining a data storage duration in the cache memory based on the analyzed content.

Description

AT

SYSTEM AND METHOD FOR PROVIDING DATA

The present invention relates to the provision of data from a storage device, in particular by means of cache memories. Typically, in communication networks such as the Internet, cache memories are used to temporarily store data and allow faster access than when the data is in permanent storage devices such as databases stored on the Internet. hard drives.

In particular, in response to a request from a client, a server extracts data from a database and then stores them in the cache memory. Thus, during subsequent requests from the same client or another client, the data is extracted from the cache memory without requiring interrogation of the database.

Since access time to cache memory is shorter than access time to disk databases, data exchange is faster. However, as caches are smaller than databases, data is stored only temporarily. The data in these caches are often managed according to seniority, with the most recent data replacing the oldest data according to the "first in - first out" principle.

Some newer techniques are aimed at storing data for a specified time based on system parameters or data parameters, such as, for example, data size, access frequency, or equipment load. In such embodiments, it is therefore the data transporting parameters that are used to determine the duration of cache storage. An example of such a technique is described in EP 1 139 232. Existing techniques are however not suitable for certain applications that give rise to sharp peaks of requests to servers.

This is the case for example in the transmission of television programs on the Internet. In such an application, the end of a program on a channel causes a multitude of requests to know the nature of the programs running on the other channels.

The servers must then interrogate the databases several times in order to obtain descriptive data of the programs in progress on each of the other channels over a very short period of time.

In addition, if the service provides for different rights depending on the customer, for example linked to different subscriptions, it is also necessary to collect this law data on other databases to constitute personalized responses to each of the customers. The servers may saturate and cause a significant drop in the quality of service.

The object of the present invention is to propose a system and a method for providing data by means of caches, able to support large peaks of access requests, particularly in the context of the dissemination of descriptive data of content. applications, such as audio, video or multimedia content.

For this purpose, the subject of the invention is a system for providing data from a storage device through a communication network and by means of at least one cache memory, the system comprising at least one management manager. data cooperating with the storage device, characterized in that the manager comprises:

means for analyzing the content of the data from the storage device; and

means for determining a parameter for storing the data in the cache memory according to the analyzed content. The invention also relates to a method for providing data, characterized in that it comprises the following steps:

- analyze the content of data from a storage device;

- assign to said data a storage duration parameter; and storing the data in at least one cache memory during this determined duration.

As a result, the system and the method of the invention make it possible to adapt the storage duration to the content of the data coming from the storage device. It is not a question of considering information of formatting or transport of the data, but to make the analysis on the content of the data that is to say on the information that they convey.

According to other features of the invention:

said data are descriptive data of application contents whose lifetime is delimited; the analysis is adapted to extract from the content of the data end-of-life information of the corresponding application content, and the determination of the storage duration parameter is carried out according to this end-of-life information;

said data is stored in at least several memories hidden during the determined storage period;

the data manager comprises means for sending a message containing both the selected data and the associated storage duration parameter to a client, this message controlling the caching of the data during the determined duration; advantageously, the invention may comprise a rights management server associated with a client rights database, this server comprising means for transmitting to a client and in response to a specific request, data relating to personal rights. from this client. The invention also relates to a data manager from a storage device, characterized in that it comprises:

means for analyzing the content of said data; and

means for determining a parameter for the duration of storage of these data in at least one cache memory as a function of the content analyzed.

Finally, the invention relates to a computer program for a data manager from a storage device, characterized in that it comprises instructions which, when executed on a computer of this data manager, make him:

- analyze the content of said data; and

determining, according to the analyzed content, a parameter for the duration of storage of this data in at least one cache memory.

The invention will be better understood in the light of the description given by way of example and with reference to the figures in which:

FIGS. 1 and 2 respectively represent a block diagram and a flow diagram of a first embodiment of the invention; and

- Figures 3 and 4 respectively show a block diagram and a flow diagram of a second embodiment of the invention.

The present invention will be described in the context of the broadcasting of audiovisual programs on the Internet. More specifically, the invention is described for providing descriptive data of television programs which are also called metadata. The content of these descriptive data includes information relating to the corresponding television program, such as the start and end times of the program as well as the title and various other information.

In the following we call "descriptive data content" the useful information transported by these data by distinction with the service information which is in particular the transport parameters such as the size of the packet formed by the descriptive data.

In a first embodiment of the invention, shown with reference to FIGS. 1 and 2, the system comprises several clients 2i to _2N connected by the Internet type network 4 to an Internet server 6. In this embodiment, all the customers have the same rights and the same capacities and are, for example, mobile telephony equipment able to receive television streams transmitted over the Internet network according to the IP protocol or over a radio network according to the DVB-H protocol. The server 6 is associated with a cache memory 8 as well as with a data manager 10 which, in this embodiment, controls the accesses to a remote database 12 formed for example of a set of hard disks which contain data. descriptive data of television programs. The data manager 10 comprises, for example, a microprocessor 13 comprising software forming means 14 for selecting data in the database 12 as well as means 16 for analyzing the content of this data and means 18 for determining their data. storage time. The microprocessor 13 is further associated with memories such as a RAM 19 by data buses not conventionally.

With reference to FIG. 2, the mode of operation of the system of the invention will now be described.

The method starts with a step 20 of issuing a request by a client 2i to the server 6 which asks the nature of the programs in progress on a given channel.

The server 6 interrogates the cache memory 8 during a step 22 and, in the case where the data are not available in the cache memory, it transmits the request to the data manager 10 during a step 24. The manager 10 using the selection means 14, extracted from the database 12 the data required during a step 26. The manager 10 then analyzes the content of these data in order to determine the end time of the program during a step 28.

16 of the manager access the content of the descriptive data to read, analyze and extract from the description of the program, the information relating to the end schedule.

The means 18 then determine a storage duration parameter in a step 30 which is a function of the analysis carried out previously. In the described embodiment, the descriptive data of a program are stored until the end time of this program and the duration parameter corresponds to the duration between the current time and the end time of the program.

The set formed of the descriptive data and the duration parameter is transmitted to the server 6 during a step 32. The server places in the cache memory 8 the descriptive data where it will be maintained for the duration determined previously, that is to say say until the end of the corresponding program.

Simultaneously, the server 6 transmits these descriptive data to the client 2i during a step 36.

Subsequently, during a step 40, another client 2N sends to the server 6 the same request as that sent previously in step 20. The server 6 interrogates the cache memory 8 during a step 42 and receives back the descriptive data constituting the answer to this request. The server 6 can then directly respond to the client 2N during a step 44 without querying the data manager 10 and the database 12.

Once the determined period has elapsed, the descriptive data is automatically erased from the cache memory. Indeed, the program with which this data was associated is terminated so that these descriptive data will no longer be issued in response to client requests.

Thus, because of the analysis of the content of the descriptive data selected in the database, the invention makes it possible to adapt the storage duration in the cache memory to the duration of the corresponding program.

As a result, only one access to the database is required to make available the descriptive data of a program. This solution is particularly adapted to the case of television programs. Indeed, it exists on each channel of the order of 20 to 50 programs and the number of requests relating to the descriptive data of these programs is very important. With reference to FIGS. 3 and 4, another embodiment of the invention will now be described.

In this embodiment, the terminals 2i to 2N are connected to the Internet network 4 via a connection equipment called Proxy server 50 which has an associated cache memory 52. Similarly, the Internet server 6 is connected to network 4 through another server

Proxy 54 which controls the cache 8.

Finally, in this embodiment, the system also comprises a rights management server 60 associated with a database 62 containing data relating to the rights of each of the customers of the service. In this embodiment, each of the clients 2i to 2N is asked to interrogate the rights server 60 during a step 70, to obtain the data relating to his personal rights during a step 72.

Thus, the personal rights of the customers are transmitted during a dedicated exchange. For example, customers have a list of channels for which they are allowed to view programs.

Subsequently, a client 2i transmits, during a step 80, a request relating to descriptive data of the current program on a channel. This request is relayed to the server 6 via the proxies 50 and 54. Each of these proxies verifies upon receipt of the request if it has the data in its associated cache memory, respectively in the memories 52 and 80.

In the example, neither of the two Proxies 50 and 54 has the response to the request, so that this request is transmitted to the server 6 which, as before, passes it to the data manager.

10 in a step 82. The manager 10 accesses the database 12 during a step 84 to extract the required data.

In a manner similar to the embodiment described with reference to FIGS. 1 and 2, these descriptive data comprise information relating to the end of life of the corresponding program. The data manager 10 analyzes the contents of the data extracted from the database during a step 88 and determines the storage duration parameter during a step 90.

In a step 92, the descriptive data as well as the storage duration parameter are transmitted to the server 6 which sends the client 2i the response to the request during a step 94.

This response is transmitted by the Proxys 50 and 54 servers each of them intercepting and relaying it to put the data in its associated cache. Thus, the proxy server 54 stores the descriptive data in the cache memory 8 during a step 96 and the proxy server 50 stores these descriptive data in the cache memory 52, during a step 98.

The storage duration parameter being transmitted with the response in step 94, each of the Proxy servers has this duration parameter and can manage its cache memory accordingly in order to store the data for the determined duration.

The propagation of the content of a cache memory on different Proxys servers connecting clients to a content server is achieved through the use of conventional technical means in the field of the Internet, such as the HTTP / IP protocol.

Subsequently, another client 2 _N issues a request 100 relating to the same descriptive data as the request 70, that is to say relating to the descriptive data of the same program on the same channel.

This request 100 is intercepted by the proxy server 50 which accesses the cache memory during a step 102 and returns directly to the data during a step 104, without relaying the request to the other equipment.

Eventually, another client directly connected to the network, and who does not have a proxy server, will see his request intercepted by the server

Proxy 54 which will access the cache memory 8 to return the required data, without relaying the request to other equipment and in particular without relaying this request to the data manager 10. Once the set time elapses, the data can be erased from all the caches. In particular, when a server wishes to store new data, the storage duration parameter associated with the descriptive data indicates that this data may be overwritten by others.

In this embodiment, the separation of the personal data relating to the rights of the customers and the descriptive data makes it possible to make the descriptive data coming from the database mutable.

Indeed, thanks to this separation, the descriptive data of the programs are identical for all the customers. However, based on their respective rights, customers can only request requests for descriptive program data to which they have access.

In addition, the propagation of the descriptive data with the corresponding storage duration attribute in the various cache memories of the network makes it possible to substantially reduce the load on the equipment associated with the Internet server 6.

Of course, other embodiments of the invention are also possible.

In particular, it is possible to propagate the descriptive program data in the cache memories spontaneously without waiting for a request from a client. For example, periodically, the descriptive data of all running programs is propagated in cache memories.

In addition, it is also possible to compile the descriptive data of several programs for transmission to a client while assigning each or groups of these descriptive data, a storage duration parameter controlling the caching.

The different elements allowing the diffusion of the service can be distributed differently. In a particular embodiment, the Internet server is confused with the data manager and the proxy server forming a single equipment managing the cache memory and the database. In other embodiments, these features are distributed in different entities.

In yet another embodiment, the rights management server and the descriptive data broadcast server are merged, and the rights databases and the descriptive databases use the same hardware resources. In such an embodiment, the rights data and the descriptive content data are, however, considered separately and transmitted in separate exchanges.

As a variant, the data manager is a device that only analyzes the content of the data and determines the storage parameter, without performing the selection of the data. In such an embodiment, the manager operates under the control of another equipment, such as a server, which receives the requests, extracts the data and returns the responses. According to one embodiment, the data manager comprises various software modules comprising instructions which, when executed, lead to the implementation of the method of the invention.

Furthermore, the invention can also be implemented with other types of applications and application content than television programs broadcast over the Internet.

For example, the cached data may also include executive data, i.e., data forming a program that can be executed by a computer, such as software applications, and especially, so-called "Javascript" applications. », Useful for access to application content.

In such an embodiment, the analysis of the content of these executive data makes it possible to determine the storage duration parameter.

Advantageously, the data stored in the cache memory comprise descriptive data and executive data. Finally, the network used may be an extended communication network or a local network or a home network.

Claims

A system for providing data from a storage device (12) across a communication network (4) and by means of at least one cache memory (8, 52), the system comprising at least one data manager (10) cooperating with the storage device, characterized in that the data manager comprises:

means (16) for analyzing the data content from the storage device; and

means (18) for determining a parameter for storing the data in the cache memory according to the analyzed content.

2. System according to claim 1, characterized in that said data are descriptive data of application contents whose lifetime is delimited.

3. System according to claim 2, characterized in that said analysis means are adapted to extract from the content of the data end-of-life information of the corresponding application content, said determination means being adapted to determine the duration parameter storage according to this end-of-life information.

4. System according to any one of claims 1 to 3, characterized in that said data comprise executive data intended to allow use of application contents.

5. System according to any one of claims 1 to 4, characterized in that it comprises a plurality of cache memories (8, 52), said data being stored in at least several of these caches during the determined storage period.

6. System according to any one of claims 1 to 5, characterized in that the data manager comprises means for transmitting a message containing both the data and the associated storage duration parameter to a client, this message controlling the caching of the data during the determined duration.

7. System according to any one of claims 1 to 6, characterized in that it further comprises a rights management server (60) associated with a database (62) rights of customers, the server comprising transmission means to a client and in response to a specific request, data relating to the personal rights of this client.

8. Method of providing data, characterized in that it comprises the following steps:

analyzing (28, 88) the data content from a storage device (12); allocating (30, 90) to said data a storage duration parameter; and

storing (34; 96; 98) the data in at least one cache memory (8, 52) during this determined period of time.

9. Method according to claim 8, characterized in that said data are descriptive data of application contents whose lifetime is delimited.

10. Method according to claim 9, characterized in that said step (28, 88) for analyzing the content of the data comprises extracting from the content of the data an end-of-life information of the corresponding application content and what said step of determining the storage duration parameter is performed according to this end of life information.

11. The method as claimed in claim 10, characterized in that said step of determining the storage duration parameter comprises determining the duration separating the current time from the end-of-life instant of the application content.

12. Method according to any one of claims 8 to 11, characterized in that said data comprise executive data intended to allow use of application contents.

13. Method according to any one of claims 8 to 12, characterized in that the storage of the data during the determined duration is performed on a plurality of cache memories (8, 52).

14. Method according to any one of claims 8 to 13, characterized in that it further comprises the following steps:

- the interrogation (70) by a client of a rights management server (60); and

- The emission (72) in return by this server and to this client, data relating to his personal rights.

15. Manager of data from a storage device (12), characterized in that it comprises: means (16) for analyzing the content of said data; and

means (18) for determining a storage time parameter for these data in at least one cache memory (8, 52) as a function of the analyzed content.

16. Computer program for a manager (10) of data from a storage device (12), characterized in that it comprises instructions which, when executed on a computer of this data manager, control the implementation of the method according to one of claims 8 to 14.