KR20100048469A - Method for content caching using cache server and browser cache, and cache server thereof - Google Patents

Abstract

PURPOSE: A method for content caching using a cache server and a browser cache, and a cache server thereof are provided to use updated contents through data communication between clients by storing the updated contents having validity after grouping plural client browser cache. CONSTITUTION: If a first client(110-1) requests contents, a cache server(130) transmits contents. The first client stores the contents as a browser cache(120-1), and the cache server classifies the 2nd to nth browser cache(120-2 to 120-n) including the first browser cache into browser cache group. The cache server inspects the validity of contents of the 1st browser cache periodically. Unless the contents have validity, the cache server requests the updated contents from the content server.

Description

Method for content caching using cache server and browser cache, and cache server

The present invention relates to a content caching method and a cache server thereof. In particular, the cache server validates the content stored in the client's browser cache to store updated content in the browser cache, and each client uses one or more adjacent browser caches. A cache server and a content caching method using a browser cache and a cache server for receiving and using updated content are provided.

In general, the number of contents (eg, videos, music, files, etc.) that a content provider (CP) provides to a client is very large. There is a heavy load for a web server to provide some or all of these to each of the multiple clients one-to-one. This is because a web server is connected to a single Internet Service Provider (ISP), whereas clients requesting content exist in multiple ISPs.

Therefore, traffic between ISPs increases exponentially as the number of content providers and clients increases, and transmission delay and / or transmission failure rate due to traffic congestion increases. In the worst case, the web server may fail over.

The CDN was introduced to overcome this problem. A CDN is a collection of content that is concentrated on a content provider's web server that is remote from clients, such as pictures, banners, video, or audio. Point-of-presence is stored in the host server which is widely distributed, and the client connects to the host server through the returned path by returning the path of the host server closest to the user when requested by the client. This service allows you to receive content. The host server is variously referred to as a cache server, a replication server, or a ghost server (hereinafter referred to as a cache server).

However, it is expensive and time-consuming for CDN operators to install and operate cache servers with capacity and response time that clients can satisfy in all regions of the world. In addition, the currently commercialized CDN service designates a cache server corresponding to the IP (Internet Protocol) address of the client, and if there is a content request from the client, checks whether the corresponding content is stored in the corresponding cache server, and is not stored. If not, it uses a method of sending a request to a content server.

However, there is a problem that if a specific content is not stored in the cache server corresponding to the client, content requests are crowded to the origin content server providing the content. . Accordingly, there is a need for a method capable of providing content requested from a client without adding a cache server.

The present invention has been proposed to solve the above-mentioned problems. When the cache server transmits content in response to a request for a content from a client and stores the content in a browser cache of the client, the content is valid due to elapsed time. It provides a cache server and a content caching method using a cache server and a browser cache to ensure that a plurality of clients receive and use the updated content by transmitting the updated content to the browser cache of the client and the adjacent client to confirm that the Its purpose is to.

Contents caching method using a cache server and a browser cache of the present invention for achieving the above object, the cache server receives the content from the content server to receive the content and the validity information for the content, the cache When the server receives a request for the content from a client corresponding to a specific browser cache, a first storage step of transmitting the content to the client to store the specific browser cache, a plurality of cache server including the specific browser cache Grouping the browser cache into a single browser cache group, and when the cache server determines that the content stored in the specific browser cache is not valid, requests and receives updated content for the content from the content server. To the group To the client that corresponds to the at least one browser cache includes a second storage step of storing to the at least one browser cache by transferring the updated content.

In the content caching method using the cache server and the browser cache of the present invention, the validity information of the content in the receiving step is characterized in that the information contained in the header of the content.

In the content caching method using the cache server and the browser cache of the present invention, in the receiving step, the validity information of the content is characterized in that it comprises one or more information of the time stamp information and the validity period information of the content.

In the content caching method using the cache server and the browser cache of the present invention, the grouping step may include: browsing the plurality of locally cached browser caches by referring to an Internet Protocol (IP) address of a client corresponding to each of the plurality of browser caches; Grouping into one browser cache group.

In the content caching method using the cache server and the browser cache of the present invention, in the grouping step, the one browser cache group is grouped to include the browser cache overlapping with another browser cache group.

In the content caching method using the cache server and the browser cache of the present invention, the second storing step is characterized in that the validity of the content is checked by checking the validity of the content according to a predetermined period.

In the content caching method using the cache server and the browser cache of the present invention, the second storing step is performed before the request for the updated content is received from a client corresponding to any browser cache belonging to the browser cache group. The updated content may be transmitted in advance.

The cache server of the present invention for achieving the above object, the database unit for storing the input and output unit for transmitting and receiving data, the content, the validity information for the content and the browser cache group information including a plurality of browser cache, and the content server When the content is received through the input and output unit from the store the content and the validity information about the content in the database unit, when receiving a request for the content from the client to transmit the content to the client corresponding to the client Store the group information in the database unit by grouping a plurality of browser caches including the specific browser cache into a single browser cache group, and storing the group information in the database unit. If it is determined that the contents are not valid by referring to the Hyosung information, the content server requests and receives updated contents of the contents through the input / output unit, and corresponds to one or more browser caches belonging to the group through the input / output unit. And a controller for transmitting the updated contents to a client and storing the updated contents in the one or more browser caches.

In the cache server of the present invention, the controller may receive the updated content from the content server through the input / output unit, store the updated content, and simultaneously transmit the updated content.

In the cache server of the present invention, the validity information on the content may include one or more of time stamp information and validity period information on the content.

In the cache server of the present invention, the controller checks the validity of the content according to a predetermined period, and confirms that the content is not valid.

According to the present invention, by grouping a plurality of adjacent client browser caches and storing the updated updated content, it is possible to use the updated content through data communication between the clients, through which the centralized cache server is concentrated. It distributes data traffic and enables network efficient use.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing in detail the operating principle of the preferred embodiment of the present invention, if it is determined that the detailed description of the related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, the same reference numerals are used for parts having similar functions and functions throughout the drawings.

1 is a block diagram of a content delivery system according to an embodiment of the present invention. Referring to Figure 1, the content delivery system of the present embodiment is the first client to the n-th client (110-1, ..., 110-n), the first browser cache to the n-th browser cache (120-1, .. , 120-n), cache server 130, content server 140, and network 150.

The first to nth clients 110-1,..., And 110-n refer to a terminal such as a computer that receives information from a server connected to the network 150. When the first client to the n-th client 110-1,..., 110-n receives a Uniform Resource Locater (URL) for requesting specific content from a browser, a DNS (Domain Name Server) Access to the IP address of the content server 140 or the cache server 130 that provides the content, and access the server corresponding to the IP address to receive the content.

The first browser cache to n-th browser caches 120-1 to 120-n are browsers of the first to n-th clients 110-1 to 110-n, respectively. The content repository corresponding to. That is, when each browser receives specific content from the content server 140 or the cache server 130, the corresponding client of the first browser cache to n-th browser cache (120-1, ..., 120-n) It is stored in the browser cache and used to display through the browser window.

The cache server 130 is called, for example, a copy server or a ghost server, and is a storage for storing a copy of content data stored and managed by the content server 140. The cache server 130 quickly responds to a content request from any one of the first to n-th clients 110-1,..., 110-n.

The content server 140 stores a web page and an object provided by the content provider, and then stores the web page and the object from one of the first to n-th clients 110-1,..., 110-n. Server that responds to content requests. That is, the content server 140 plays a role of transmitting content requested from a specific client, and transmits and stores some of the content held by the content server 140 to the cache server 130. Through this, it is possible to quickly provide the content according to the request of the specific client in the cache server (130).

The network 150 refers to a data communication network for data transmission and information exchange between the first to nth clients 110-1,..., 110-n, the cache server 130, and the content server 140. do.

For example, when the cache server 130 receives a content request from the first client 110-1 while receiving and storing the content from the content server 140, the cache server 130 transmits the corresponding content, and the first client 110-. 1) receives the corresponding content and stores it in the first browser cache 120-1.

The cache server 130 converts the second browser cache to the n-th browser cache 120-2,..., 120-n including the first browser cache 120-1 into one browser cache group. Grouping

The cache server 130 periodically checks the validity of the content stored in the first browser cache 120-1 by using a time stamp. If a predetermined time elapses from the time when the time stamp is generated, the cache server 130 requests and receives updated content of the corresponding content from the content server 140.

The received updated content is transmitted to one or more clients of the first to n th clients 110-1,..., 110-n to transmit the first to n th browser caches 120-1, ... , 120-n) is stored in the corresponding browser cache.

The first browser cache, n-th browser cache 120-1, ..., 120-n, which is grouped into a browser cache group, corresponds to the locally adjacent clients 110-1, ..., 110-n. It may be a cache. In general, since data transmission / reception rates are relatively fast between locally adjacent clients, the first to n-th clients 110-1,..., 110-n are not connected to each other without receiving specific content from the cache server 130. It is possible to receive and use updated contents through data transmission and reception between them.

In particular, when the updated content is large and the network status of the cache server 130 is not good, it is possible to directly receive and use the updated content from the browser cache of an adjacent client by using Peer to Peer (P2P) method. Do.

The configuration and operation of the cache server 130 according to an embodiment of the present invention will be described in more detail with reference to FIG. 2.

2 is a configuration diagram of the cache server 130 shown in FIG. 1 according to an embodiment of the present invention. Referring to FIG. 2, the cache server 130 according to the present exemplary embodiment includes an input / output unit 210, a controller 220, and a database unit 230.

The input / output unit 210 has an interface for transmitting and receiving data through the network 150.

The database unit 230 is a storage storing browser cache group information including content, validity information of the content, and a plurality of browser caches. The database unit 230 includes content information stored in the first browser cache to n-th browser cache 120-1,..., 120-n.

When the controller 220 receives the content from the content server 140 through the input / output unit 210, the controller 220 stores the content and validity information about the content in the database unit 230. For example, the header of the received content data may include validity information such as time stamp information and expiration date information of the content.

Thereafter, when the controller 220 receives a content request from a specific client through the input / output unit 210, the controller 220 transmits the corresponding content stored in the database unit 230 to the client to store the corresponding browser cache.

The controller 220 groups the browser caches corresponding to the plurality of clients including the specific client that has received the content into one browser cache group, and stores the browser cache group information in the database unit 230. In this case, the browser caches that are grouped may be browser caches that are locally adjacent to each other, and the reason is that transmission rates between clients corresponding to browser caches that are locally adjacent are generally fast. Groups of browser caches that are grouped may be grouped to include the browser cache, overlapping with other browser cache groups.

The controller 220 refers to the validity information of the content stored in the database 230 to check whether the corresponding content is valid. As described above, the validity information on the content may include time stamp information and expiration date information on the content, etc. In this case, the controller 230 checks whether the validity period has elapsed from the time stamp generation time of the content. You can check the validity of Validation of the content may be performed periodically at regular time intervals.

If the validity period has elapsed since the validity check result of the timestamp generation time for the content, and the control unit 220 determines that the validity is not corrected, the controller 220 transmits the updated content corresponding to the corresponding content to the content server 140 through the input / output unit 210. The request is received and stored in the database unit 230.

Thereafter, the controller 220 transmits the updated content stored in the database 230 to a client corresponding to one or more browser caches belonging to the browser cache group to store the updated content in each browser cache.

At this time, the updated content storage in the browser cache may be made in advance before a request for updated content is received from any client corresponding to the browser cache belonging to the browser cache group. In this way, the transmission of the updated content may be made in the browser cache of another client, not the cache server 130. In this case, the updated content may be transmitted, for example, in a Peer to Peer (P2P) manner.

Information held by the database unit 230 according to an embodiment of the present invention will be described in more detail with reference to FIGS. 3 and 4.

3 is an exemplary diagram of a validity information table 300 stored in the database unit 230 of FIG. 2 according to an embodiment of the present invention. Referring to FIG. 3, the validity information table 300 includes items of contents, time stamps, validity periods, and validity.

The content item is a field including content information stored in the cache server 130 or the first through n-th browser caches 120-1, ..., 120-n.

The time stamp item is a field including time information of each content generated.

The validity period item is a field including duration information that the corresponding content has validity from the time indicated by the time stamp.

The validity item is a field containing information on whether each content is valid.

Referring to the content item, the content stored in the cache server 130 or the first browser cache to n-th browser cache (120-1, ..., 120-n) is 'image1.gif', 'image2.gif', You can see that it is 'image3.gif', ... and so on.

It can be seen that the time stamp of the content of 'image1.gif' is 'xxxx-xx-xx-xx' and the validity period is 30 minutes (min: minute) from the time stamp generation time. When the corresponding validity item is referred to as 'N (none)', the validity period elapses from the time stamp generation time, indicating that the content is invalid. This means that there is no reliability of the corresponding content or there is updated content corresponding to the corresponding content in the content server 140.

On the other hand, the time stamp of the 'image2.gif' content is 'yyyy-yy-yy-yy', and the validity period is 20 minutes from the time stamp generation time, and the corresponding validity item is 'Y (yes)'. You can see that this is content. Similarly, the time stamp of the 'image3.gif' content is 'zzzz-zz-zz-zz', the validity period is 20 minutes from the time stamp generation time, and the validity item is 'Y', indicating that the content is valid. have.

4 is an exemplary diagram of a browser cache group table 410 and a link information table 420 stored in the database unit 230 of FIG. 2 according to an embodiment of the present invention.

Referring to the browser cache group table 410 in FIG. 4, the client IP address and the browser cache group item are configured. The link information table 420 also consists of a browser cache group, a client IP address, and a stored content item.

In the browser cache group table 410, a client IP address item is a field including IP address information corresponding to each client. The browser cache group item is a field including information of the browser cache group to which the browser cache corresponding to each client IP address belongs.

In the link information table 420, the browser cache group item is an information field linked to each browser cache group item in the browser cache group table 410, and the link of the information is, for example, a linked list. It may be made in the form of). The client IP address item is a field containing IP address information of clients belonging to each browser cache group. The stored content item is a field indicating information of content stored in the browser cache of each client.

Referring to the browser cache group table 410, it can be seen that the browser cache of the client whose IP address is '111.111.111.110' belongs to the first group. In the item of the link information table 420 linked to the first group item, the IP address of the client browser cache belonging to the first group is '111.111.111.110', '111.111.111.111', '111.111.111.112', ... It can be seen that.

At this time, the contents stored in the browser cache of the client whose IP address is '111.111.111.110' are 'image1.gif' and 'image2.gif'. Similarly, the image of the client having the IP address of '111.111.111.111' is 'image1.' You can see that the contents of '.gif' and 'image3.gif' are stored and the contents of 'image2.gif' and 'image3.gif' are stored in the browser cache of the client whose IP address is '111.111.111.112'. have.

For example, when a client having an IP address of '111.111.111.110' requests a content of 'image1.gif' from the cache server 130, the cache server 130 transmits the content to a client having '111.111.111.110'. To store the corresponding browser cache.

A plurality of browser caches are grouped into a first group, including a browser cache corresponding to a client having an IP address of '111.111.111.110', and a browser cache group table 410 and a link information table 420 are generated or updated. .

Thereafter, the cache server 130 checks the validity of 'image1.gif' with reference to the validity information table 300 stored in the database unit 230 according to a preset time or a predetermined period. If 'image1.gif' is identified as an invalid content, the content server 140 requests and receives updated content corresponding to 'image1.gif'.

In addition, the cache server 130 confirms that the browser cache corresponding to the client having the IP address '111.111.111.110' belongs to the first group in the browser cache group table 410, and the link information table linked to the first group ( 420), the IP addresses of the clients belonging to the first group are '111.111.111.110', '111.111.111.111', '111.111.111.112', ... and the like, and the contents of 'image1.gif' Confirm that the client IP addresses corresponding to the saved browser cache are '111.111.111.110' and '111.111.111.112'.

Thereafter, the cache server 130 transmits and stores the updated content to one or more browser caches belonging to the first group. For example, when the updated content is stored only in the browser cache corresponding to the IP address '111.111.111.110', when the client having the IP address '111.111.111.112' requests the updated content, the cache server 130 requests the IP. The address '111.111.111.110' can be returned to the client with the IP address '111.111.111.112' to establish a link between both clients and receive data.

A content caching process according to an embodiment of the present invention will be described in more detail with reference to FIG. 5.

5 is a flowchart of a content caching method according to an embodiment of the present invention. 1 and 5, the cache server 130 receives the content from the content server 140 and stores the content and the validity information of the content (S510). For example, the validity information of the content may be information included in a header of the content data received in operation S510. The validity information of the content may include at least one of time stamp information and validity period information of the content.

Thereafter, when the cache server 130 receives a content request from the first client 110-1 corresponding to the first browser cache 120-1 (S520), the cache server 130 transmits the corresponding content to the first client. The data is transmitted to 110-1 to be stored in the first browser cache 120-1 (S530).

The cache server 130 groups the plurality of browser caches including the first browser cache 120-1 into one browser cache group (S540). For example, the grouping in step S540 may refer to the IP address of the first client 110-1, select one or more clients locally adjacent to the first client 110-1, and select each client. This may be achieved by grouping the browser cache corresponding to the group into one browser cache group.

Thereafter, the cache server 130 checks the validity of the stored content transmitted to the first browser cache 120-1 (S550). For example, the validity check in step S550 may be performed by referring to time stamps and valid period information of each content stored in step S510.

If it is determined that the validity period of the content is not valid after the validity verification step (S550), the cache server 130 requests the updated content to the content server 140 (S560) and receives it (S570). In this case, the received updated content is stored in a database or the like in the cache server 130.

The cache server 130 transmits the updated contents to one or more clients including the first client 110-1, and the one or more browser caches including the first browser cache 120-1 among the browser caches belonging to the browser cache group. The updated content is stored in step S580.

The updated content transmission and storage in step S580 may be made in advance before a request for updated content is received from a client corresponding to any browser cache among the browser caches grouped in step S540. Through this, when the cache server 130 receives a request for updated content from any client, the cache server 130 may return the IP address of the client corresponding to the browser cache storing the updated content to receive the updated content. have.

According to the present invention, the cache server confirms that the content stored in the browser cache of the client is not valid and transmits and stores updated content in one or more browser caches among a plurality of browser caches including the corresponding browser cache, thereby storing the specific client. If there is a request for updated content from the client, the updated content may be received from the browser cache of the client storing the updated content. Through this, the traffic concentrated on the cache server can be distributed, and the cost of the expansion and management of the cache server for the transmission speed can be reduced.

1 is a block diagram of a content delivery system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of the cache server shown in FIG. 1.

3 is an exemplary diagram of a validity information table stored in a database unit of FIG. 2.

4 is an exemplary diagram of a browser cache group table and a link information table stored in the database unit of FIG. 2.

5 is a flowchart of a content caching method according to an embodiment of the present invention.

Claims (11)

Receiving step of the cache server receives the content from the content server to store the content and the validity information for the content; A first storage step of transmitting the content to the client and storing the content in the specific browser cache when the cache server receives a request for the content from the client corresponding to the specific browser cache; A grouping step of the cache server grouping a plurality of browser caches including the specific browser cache into one browser cache group; And If the cache server determines that the content stored in the specific browser cache is invalid, the cache server requests and receives updated content for the content from the content server, and updates the client to one or more browser caches belonging to the group. A second storage step of transmitting the stored contents and storing the at least one browser cache; Content caching method using a cache server and browser cache comprising a. The method of claim 1, wherein in the receiving step Validity information for the content is a content caching method using a cache server and a browser cache, characterized in that the information contained in the header of the content. The method of claim 1, wherein in the receiving step The validity information of the content includes a cache server and a browser cache, characterized in that it comprises at least one of time stamp information and validity information of the content. The method of claim 1, wherein the grouping step Contents using a cache server and a browser cache, characterized by grouping the plurality of locally cached browser caches into the one browser cache group with reference to the IP (Internet Protocol) address of the client corresponding to each of the plurality of browser caches Caching method. The method of claim 1, wherein in the grouping step And the one browser cache group is grouped to include the browser cache overlapping with the other browser cache group. The method of claim 1, wherein the second storage step The content caching method using a cache server and a browser cache, characterized in that to verify the validity of the content by checking the validity of the content according to a predetermined period. The method of claim 1, wherein the second storage step And a cache server and a browser cache, wherein the updated content is transmitted in advance before a request for the updated content is received from a client corresponding to any browser cache belonging to the browser cache group. Input and output unit for transmitting and receiving data; A database unit which stores contents, browser cache group information including a plurality of browser cache information and validity information about the contents; And When the content is received from the content server through the input / output unit, the content is stored in the database unit and the validity information about the content, and when the client receives a request for the content, the content is transmitted to the client to the client. Store the group information in the database unit by grouping a plurality of browser caches including the specific browser cache into one browser cache group, and validating the contents stored in the database unit. If it is determined that the content is not valid with reference to the information, the content server requests and receives updated content for the content through the input / output unit, and receives one or more blocks belonging to the group through the input / output unit. A control unit for the transmitting the updated content to the client cache corresponding to distributors or more to store the browser cache; Cache server comprising a. The method of claim 8, wherein the control unit The cache server, characterized in that for receiving the updated content from the content server via the input and output unit and storing the updated content at the same time and the updated content. The method of claim 8, wherein the validity information of the content is And at least one of time stamp information and expiration date information for the content. The method of claim 8, wherein the control unit The cache server, characterized in that for checking the validity of the content according to a predetermined period to confirm that the validity of the content.

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