Data distribution server

• US 7,404,201 B2
• Filed: 02/12/2004
• Issued: 07/22/2008
• Est. Priority Date: 02/14/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kobayashi, Ikuko, Takeuchi, Tadashi, Mine, Hiroshi, Le Moal, Damien
• Primary Examiner(s): Huynh; Son P
• Application Number:
  US10/778,628
• Publication Number:
  US 20040230996A1
• Time in Patent Office: 1,622 Days
• Field of Search: 725 91- 92, 725/145, 725 86- 87, 709/203, 709/231, 709217-219
• US Class Current: 725/109
• CPC Class Codes: G06F 16/958 Organisation or management of web site content, e.g. publishing, maintaining pages or automatic linking
• CPC Class Codes: H04N 21/2181 comprising remotely distributed storage units, e.g. when movies are replicated over a plurality of video servers distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: H04N 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/6125 involving transmission via Internet transmission by internet of broadcast information H04H60/82
• CPC Class Codes: H04N 21/6175 involving transmission via Internet broadcast-related systems characterised by the transmission system being the Internet H04H60/82
• CPC Class Codes: H04N 7/17336 Handling of requests in head-ends

Abstract

A copy computer includes a storage device which stores a copy of contents from a distribution computer and a module which creates a copy of updated contents based on a copy request and which sends a copy of contents requested by a search computer to a distribution request computer. The search computer includes a module which searches for a copy computer storing the copy of the contents requested by the distribution request computer, a module which forwards a send request to a specified copy computer, and a module which sends the copy request and the copy contents to a predetermined copy computer when the contents are updated. The copy request gives an instruction to create the copy of the updated contents in the storage device of the copy computer.

Claims

1. A network system, comprising:

a distribution computer including a distribution storage device;

a distribution request computer configured to issue a send request to obtain contents stored in said distribution storage device;

a plurality of copy computers, each copy computer including a copy storage device configured to store as copy contents a copy of selected contents of said contents stored in said distribution storage device, the distribution computer being configured to designate a selected one of the plurality of copy computers to store a copy of the selected contents in the storage device under control thereof, the plurality of copy computers being located at positions closer to the distribution request computer than the distribution computer; and

a search computer in communication with the distribution computer and one of the plurality of copy computers, the search computer including a contents search module configured to send a contents search request to the first copy computer based on said send request,

wherein each copy computer further includes a server list configured to store information indicating another copy computer,

wherein the distribution computer further includes a contents registration module which, when the contents in the distribution storage device are updated, sends a copy request and copy contents of the updated contents to the designated one of said plurality of copy computers, the copy request giving an instruction to create the copy contents in the copy storage device of the designated copy computer,

wherein, when receiving a copy request from the distribution computer, the copy computer receiving the request creates a copy of the updated contents in the storage device under control thereof,

wherein, when receiving a send request from said distribution request computer, the search computer sends a contents search request to the one of the plurality of copy computers,

wherein, when receiving the contents search request from the search computer, the copy computer receiving the request searches the copy storage device under control thereof to determine whether a copy of the contents being searched exists in the copy storage device, returns the copy of the contents to the search computer if the copy of the contents exists, determines whether the information indicating another copy computer of the plurality of copy computers is stored in the server list if the copy of the contents does not exist, forwards the contents search request to the another copy computer indicated by the information if the information is stored in the server list, and sends an error notification to the search computer if the information is not stored in the server list,

wherein the search computer sends the contents to the distribution request computer upon receiving the contents from the copy computer,

wherein the search computer sends the send request to the distribution computer upon receiving the error notification from the copy computer,

wherein the contents registration module sends the copy request and the copy contents to the designated one of the plurality of copy computers when receiving the send request from the search computer,

wherein said send request issued by said distribution request computer is based on a transmission protocol selected from HTTP and RTSP,

wherein each of the distribution computer, search computer, and plurality of copy computers include a distribution module programmed to communicate using a distribution protocol that is independent of the transmission protocol, such that contents are able to be written to, and read from, said distribution storage device regardless of a difference between the transmission protocol and the distribution protocol and without setting a disk capacity for each server application accessing said contents,

wherein the distribution computer further periodically activates the contents registration module to determine whether new contents are to be stored from a storage device, and when new contents are to be stored, read the new contents and send the new contents and a contents registration request to the plurality of copy computers, and

wherein the contents registration module when activated controls a time to send the new contents to the plurality of copy computers according to one of a state of the network system and a type of the new contents.

2. A network system according to claim 1, wherein, based on a type of said contents or a state of said network system, said contents registration module of said distribution computer specifies said selected one of said plurality of copy computers to which said copy request and said copy contents are to be sent.

3. A network system according to claim 2, wherein said contents search module of said search computer searches for one of said plurality of copy computers based on a map.

4. A network system according to claim 1, wherein said contents registration module of said distribution computer controls a timing for sending said copy request and said copy contents based on a type of said contents or a state of said network system.

5. A network system according to claim 1, wherein said contents search module of said search computer searches for one of said plurality of copy computers based on a map.

6. A network system comprising:

a distribution computer including a distribution storage device which stores contents;

a distribution request computer which issues a send request to obtain said contents;

a plurality of copy computers, each copy computer including a copy storage device configured to store as copy contents a copy of selected contents of said contents stored in said distribution storage device, each copy computer further including a server list configured to store information indicating another copy computer, and the distribution computer being configured to designate a selected one of the plurality of copy computers to store a copy of the selected contents in the storage device under control thereof, whereby the plurality of copy computers being located at positions closer to the distribution request computer than the distribution computer;

a search computer in communication with the distribution computer and one of the plurality of copy computers; and

a distribution protocol-supporting computer including a contents registration module which, when said contents are updated in said distribution storage device, sends a copy request and copy contents of said updated contents to the designated one of said plurality of copy computers, said copy request giving an instruction to create said copy contents in said storage device of said designated copy computer,

wherein, when receiving a copy request from the distribution protocol-supporting computer, the copy computer receiving the request creates a copy of said updated contents in the storage device under control thereof,

wherein, when receiving a send request from said distribution request computer, the search computer sends a contents search request to the one of the plurality of copy computers,

wherein, when receiving the contents search request from the search computer, the copy computer receiving the request searches the copy storage device under control thereof to determine whether a copy of the contents being searched exists in the copy storage device, the copy computer returns the copy of the contents to the search computer if the copy of the contents exists, the copy computer determines whether the information indicating another copy computer of the plurality of copy computers is stored in the server list if the copy of the contents does not exist, the copy computer forwards the contents search request to the another copy computer indicated by the information if the information is stored in the server list, and the copy computer sends an error notification to the search computer if the information is not stored in the server list,

wherein the search computer sends the contents to the distribution request computer upon receiving the contents from the copy computer,

wherein the search computer sends the send request to the distribution protocol-supporting computer upon receiving an error notification from the copy computer,

wherein the contents registration module sends the copy request and the copy contents to the designated one of the plurality of copy computers when receiving the send request from the search computer,

wherein said send request issued by said distribution request computer is based on a transmission protocol selected from HTTP and RTSP,

wherein each of the distribution computer, distribution protocol-supporting computer, search computer, and plurality of copy computers include a distribution module programmed to communicate using a distribution protocol that is independent of the transmission protocol, such that contents are able to be written to, and read from, said distribution storage device regardless of a difference between the transmission protocol and the distribution protocol and without setting a disk capacity for each server application accessing said contents,

wherein the contents registration module is periodically activated to determine whether new contents are to be stored from a storage device, and when new contents are to be stored, read the new contents and send the new contents and a contents registration request to the plurality of copy computers, and

wherein the contents registration module when activated controls a time to send the new contents to the plurality of copy computers according to one of a state of the network system and a type of the new contents.

7. A computer-readable medium containing computer program software implementing procedures for storing copy contents of contents stored in a contents distribution computer into a determined copy computer of a plurality of copy computers, the computer program software including instructions that being executed by a processor, cause the processor to perform the steps of:

receiving to a first copy computer of a plurality of copy computers a search request from a search request computer to determine whether said copy contents are stored in a storage device of the first copy computer, based on a send request from a distribution request computer to send said contents, the copy contents existing at most once in the plurality of copy computers;

carrying out a search as to whether said copy contents are stored in the storage device of the first copy computer, based on said search request;

sending the copy contents to the search request computer when said copy contents are stored in the storage device of the first copy computer;

storing server list information identifying at least a second copy computer in the plurality of copy computers in a server list, including a requesting server address indicating said search computer and a forwarding destination address indicating said second copy computer;

determining whether said information corresponding to said search request computer having sent said search request is stored in said server list;

forwarding said search request to said second copy computer identified by said forwarding destination address included in said information when said copy contents are not stored in the storage device of the first copy computer and said information is stored in said server list, such that if a storage device of the second computer stores said copy contents the second copy computer is configured to send said copy contents to said distribution search request computer;

sending an error notification to the search request computer when said copy contents are not stored in the storage device of the first copy computer and said information is not stored in said server list, such that said search request computer sends said send request to said distribution computer,

wherein said send request issued by said distribution request computer is based on a transmission protocol selected from HTTP and RTSP,

wherein each of the contents distribution computer, search computer, and plurality of copy computers include a distribution module programmed to communicate using a distribution protocol that is independent of the transmission protocol, such that contents are able to be written to, and read from, one of the storage devices regardless of a difference between the transmission protocol and the distribution protocol and without setting a disk capacity for each server application accessing said contents,

wherein a contents registration module is periodically activated to determine whether new contents are to be stored from a storage device, and when new contents are to be stored, read the new contents and send the new contents and a contents registration request to the plurality of copy computers, and

wherein the contents registration module when activated controls a time to send the new contents to the plurality of copy computers according to one of a state of the network system and a type of the new contents.

8. A network system comprising:

a distribution computer including a distribution storage device which stores contents;

a distribution request computer operable to issue a send request to obtain contents stored in said distribution storage device;

a plurality of copy computers, each copy computer including a copy storage device configured to store as copy contents a copy of selected contents of said contents stored in said distribution storage device, the distribution computer being configured to designate a selected one of the plurality of copy computers to store a copy of the selected contents in the storage device under control thereof, the plurality of copy computers being located at positions closer to the distribution request computer than the distribution computer;

a search computer in communication with the distribution computer and one of the plurality of copy computers, the search computer including a contents search module configured to send a contents search request to said one of the plurality of copy computers based on said send request; and

a contents registration module which, when the contents in the distribution storage device are updated, sends a copy request and copy contents of said updated contents to the designated one of said plurality of copy computers, said copy request giving an instruction to create said copy contents in said storage device of said designated copy computer;

wherein each copy computer further includes a server list configured to store information including a request type indicating said copy request or said contents search request, a requesting server address indicating said distribution computer or said search computer, and a forwarding destination address indicating another copy computer,

wherein, when receiving said contents search request from said search computer, said copy computer searches said copy storage device under control thereof to determine whether a copy of said contents being searched exists in said copy storage device, returns said copy of said contents to said search computer if said copy of said contents exists, determines whether said information corresponding to said contents search request and said search computer which has sent said search request is stored in said server list, if said copy of said contents does not exist in said copy storage device, forwards said contents search request to said another copy computer indicated by said forwarding destination address included in said information if said corresponding information is stored in said server list, and sends an error notification to the search computer if the information is not stored in the server list,

wherein said search computer sends said contents to said distribution request computer upon receiving said contents from said copy computer,

wherein said search computer sends said send request to said distribution computer upon receiving said error notification from said copy computer,

wherein said contents registration module sends said copy request and said copy contents to said designated one of said plurality of copy computers when receiving said send request from said search computer,

wherein, when receiving said copy request and said copy contents from said contents registration module, said copy computer stores a copy of said contents in said copy storage and forwards said copy request and said copy contents to said another copy computer indicated by said forwarding destination address included in said information if said information corresponding to said copy request and said distribution computer is stored in said server lists

wherein said send request issued by said distribution request computer is based on a transmission protocol selected from HTTP and RTSP,

wherein each of the distribution computer, search computer, and plurality of copy computers include a distribution module programmed to communicate using a distribution protocol that is independent of the transmission protocol, such that contents are able to be written to, and read from, said distribution storage device regardless of a difference between the transmission protocol and the distribution protocol and without setting a disk capacity for each server application accessing said contents,

wherein the contents registration module is periodically activated to determine whether new contents are to be stored from a storage device, and when new contents are to be stored, read the new contents and send the new contents and a contents registration request to the plurality of copy computers, and

wherein the contents registration module when activated controls a time to send the new contents to the plurality of copy computers according to one of a state of the network system and a type of the new contents.