Cache server having a cache-data-list table storing information concerning data retained by other cache servers

• US 20020129207A1
• Filed: 06/12/2001
• Published: 09/12/2002
• Est. Priority Date: 02/23/2001
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Ikeda, Hitoshi, Shibata, Keiichiro, Matsumoto, Takesi
• Granted Patent: US 6,757,726 B2
• Time in Patent Office: Days
• US Class Current: 711/141
• CPC Class Codes: H04L 67/288 Distributed intermediate devices, i.e. intermediate devices for interaction with other intermediate devices on the same level
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

A cache server is provided in an internal network. The cache server comprises a cache-data-list table and a cache-data-list administrating unit. The cache-data-list table stores information concerning data retained by other cache servers on an individual cache server basis. The cache-data-list administrating unit receives a data-inquiry request from one of the other cache servers, and searches the cache-data-list table for cache-server information indicating another one of the other cache servers retaining data regarding the data-inquiry request so as to send the cache-server information to the one of the other cache servers.

Claims

1. A cache server provided in an internal network, the cache server comprising:

a cache-data-list table storing information concerning data retained by other cache servers on an individual cache server basis; and

a cache-data-list administrating unit receiving a data-inquiry request from one of said other cache servers, and searching said cache-data-list table for cache-server information indicating another one of said other cache servers retaining data regarding said data-inquiry request so as to send said cache-server information to said one of said other cache servers.

2. The cache server as claimed in claim 1, further comprising:

a relative-position information table storing information indicating a distance between each two of said other cache servers; and

a control-data sending and receiving unit obtaining a distance between said one of said other cache servers and said another one of said other cache servers from said relative-position information table so as to order said one of said other cache servers to retain said data regarding said data-inquiry request depending on said distance.

3. The cache server as claimed in claim 2, wherein said control-data sending and receiving unit orders said one of said other cache servers to retain said data regarding said data-inquiry request when said distance is larger than a predetermined distance.

4. A distributed cache server system provided in an internal network, the distributed cache server system comprising:

an owner cache server; and

member cache servers, each of which retains data from an external network, and sends information concerning said data to said owner cache server so that said owner cache server stores said information so as to search for cache-server information therefrom indicating one of said member cache servers retaining data regarding a data-obtain request received from within said internal network,

wherein, when said owner cache server finds said cache-server information, another one of said member cache servers obtains the data regarding said data-obtain request from said one of said member cache servers, and

when said owner cache server does not;

find the cache-server information, said another one of said member cache servers obtains the data regarding said data-obtain request from said external network.

5. The distributed cache server system as claimed in claim 4, wherein said owner cache server includes:

a cache-data-list table storing said information; and

a cache-data-list administrating unit receiving a data-inquiry request from another one of said member cache servers, and searching said cache-data-list table for the cache-server information indicating the one of said member cache servers retaining data regarding said data-inquiry request so as to send said cache-server information to said another one of said member cache servers.

6. The distributed cache server system as claimed in claim 5, wherein said owner cache server includes:

a relative-position information table storing information indicating a distance between each two of said member cache servers; and

a control-data sending and receiving unit obtaining a distance between said one of said member cache servers and said another one of said member cache servers from said relative-position information table so as to order said another one of said member cache servers to retain said data regarding said data-inquiry request depending on said distance.

7. The distributed cache server system as claimed in claim 4, wherein each of said member cache servers includes:

a cache-data DB retaining the data from said external network; and

a cache-data sending and receiving unit sending information concerning said data retained from said external network to said owner cache server.

8. The distributed cache server system as claimed in claim 7, wherein each of said member cache servers includes:

a keyword-information table storing keywords; and

a cache-data administrating unit counting a number of times each of said keywords appears in said data obtained from said one of said member cache servers,

so that said another one of said member cache servers retains said data obtained from said one of said member cache servers in said cache--data DB depending on said number of the times.

9. A distributed cache server system provided in an internal network, the distributed cache server system comprising:

groups of a cache server and other cache servers, the groups being configured in a hierarchical structure, each of said other cache servers retaining data from an external network, and sending information concerning said data to said owner cache server in each of said groups so that said owner cache server stores said information so as to search for cache-server information therefrom indicating one of said other cache servers retaining data regarding a data-obtain request received from within said internal network,

wherein, when said owner cache server finds said cache-server information, another one of said other cache servers in each of said groups obtains the data regarding said data-obtain request from said one of said other cache servers, and

when said owner cache server does not find the cache-server information, said another one of said other cache servers in each of said groups obtains the data regarding said data-obtain request from one of said external network and the others of said groups.