Network retrieval system, information retrieval method, bridge device and program

• US 20060047786A1
• Filed: 05/16/2005
• Published: 03/02/2006
• Est. Priority Date: 05/19/2004
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Doi, Yusuke
• Application Number:
  US11/129,433
• Publication Number:
  US 20060047786A1
• Time in Patent Office: Days
• US Class Current: 709/220
• CPC Class Codes: H04L 45/742 Route cache; Operation thereof
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 61/4552 Lookup mechanisms between a plurality of directories; Synchronisation of directories, e.g. metadirectories

Abstract

There is provided network retrieval system, information retrieval method, bridge device and program in which in case where any one of plural computers arranged on a network is instructed to retrieve certain information, the plural computers cooperate to retrieve the certain information by using a distributed hash table according to a distributed hash algorithm. A client device requests a bridge device to resolve a domain name; the bridge device selects one of converting devices arranged correspondingly to the computers; the bridge device notifies the client device of a location of the selected converting device; the client device requests the selected converting device to resolve the domain name; the converting device instructs the corresponding computer to carry out retrieval based on a name resolving request to receive a retrieved result; and the converting device transmits the retrieved result as a response to the name resolving request to the client device.

Claims

1. A network retrieval system including plural computers arranged on a network in which in case where any one of the computers is instructed to retrieve certain information, the plural computers cooperate to retrieve the certain information by using a distributed hash table according to a distributed hash algorithm, comprising:

plural converting devices arranged correspondingly to the plural computers, wherein each converting device has authority to manage a first domain as a part of a domain name space, and in case of receiving a name resolving request for a domain name including the first domain, instructs the corresponding computer to carry out retrieval based on the name resolving request and receives a result retrieved according to the distributed hash algorithm from the corresponding computer to transmit the retrieved result as a response to the name resolving request;

a bridge device that manages the converting devices and has authority to manage a second domain whose hierarchy is higher than that of the first domain, and in case of receiving a name resolving request for the domain name including the first domain, notifies a transmission source of the name resolving request of at least any location of the converting devices to which the name resolving request is entrusted; and

a client device that requests the bridge device to resolve the domain name including the first domain to acquire the location of the converting device to which a name resolving request is entrusted, and requests the converting device having the acquired location to resolve the domain name including the first domain to acquire a retrieved result from the converting device.

2. The network retrieval system according to claim 1, wherein

the bridge device calculates time-to-live of the location of the converting device and notifies the client device of the time-to-live together with the location of the converting device, and

in case where a previously acquired location is within the time-to-live, the client device requests the converting device having the location within the time-to-live to resolve the domain name including the first domain.

3. The network retrieval system according to claim 2, wherein the bridge device calculates the time-to-live according to a loading state of the computer corresponding to the converting device.

4. The network retrieval system according to claim 2, wherein the bridge device calculates the time-to-live according to a loading state of itself.

5. An information retrieval method in which in case where any one of plural computers arranged on a network is instructed to retrieve certain information, the plural computers cooperate to retrieve the certain information by using a distributed hash table according to a distributed hash algorithm, comprising:

requesting by a client device a bridge device to resolve a domain name including a first domain as a part of domain name space, the bridge device having authority to manage a second domain whose hierarchy is higher than that of the first domain;

selecting by the bridge device at least any one of converting devices arranged correspondingly to the computers, the converting devices having authority to manage the first domain, respectively;

notifying by the bridge device the client device of a location of the selected converting device to which a name resolving request is entrusted;

requesting by the client device the converting device having the notified location to resolve the domain name including the first domain;

instructing by the converting device the corresponding computer to carry out retrieval based on a name resolving request from the client device, to receive a result retrieved according to the distributed hash algorithm from the corresponding computer; and

transmitting by the converting device the retrieved result as a response to the name resolving request to the client device.

6. The information retrieval method according to claim 5 further comprising;

calculating by the bridge device time-to-live of the location of the converting device and notifies the client device of the time-to-live together with the location of the converting device, and

in case where a previously acquired location is within the time-to-live, requesting by the client device the converting device having the location within the time-to-live to resolve the domain name including the first domain.

7. The information retrieval method according to claim 6, comprising calculating the time-to-live according to a loading state of the computer corresponding to the converting device.

8. The information retrieval method according to claim 6, comprising calculating the time-to-live according to a loading state of itself.

9. A bridge device that has authority to manage certain domain in a domain name space, comprising:

a management unit that manages plural computers arranged on a network, wherein in case where one of the computers is instructed to retrieve certain information, the plural computers cooperate to retrieve the certain information by using a distributed hash table according to a distributed hash algorithm;

a selecting unit that selects at least any one of the plural computers in case of receiving a name resolving request for a domain name including the certain domain; and

a responding unit that transmits a location of the selected computer as a response to the name resolving request.

10. The bridge device according to claim 9, wherein the responding unit transmits the location of the selected computer as a destination of a computer to which the name resolving request is entrusted.

11. The bridge device according to claim 9, wherein

the bridge device further comprises a time-to-live calculation unit calculating time-to-live of the location of the computer, and

the responding unit transmits the time-to-live together with the location of the computer.

12. The bridge device according to claim 11, wherein

the management unit calculates a loading state of the computer, and

the time-to-live calculation unit calculates the time-to-live according to the calculated loading state.

13. The bridge device according to claim 11, wherein

the management unit calculates a loading state of itself, and

the time-to-live calculation unit calculates the time-to-live according to the calculated loading state.

14. A program for inducing a device that has authority to manage certain domain in a domain name space, to execute:

receiving a name resolving request for a domain name including the certain domain;

selecting at least any one of plural computers arranged on a network, wherein in case where any one of the computers is instructed to retrieve certain information, the plural computers cooperate to retrieve the certain information by using a distributed hash table according to a distributed hash algorithm; and

transmitting a location of the selected computer as a response to the name resolving request.

15. The program according to claim 14, wherein the transmitting includes transmitting the location of the selected computer as a destination of a computer to which the name resolving request is entrusted.

16. The program according to claim 14, for inducing the device to execute further:

calculating time-to-live of the location of the computer, and

transmitting the time-to-live together with the location of the computer.

17. The program according to claim 16, for inducing the device to execute further calculating a loading state of the computer, wherein

the calculating the time-to-live includes calculating the time-to-live according to the calculated loading state.

18. The program according to claim 16, for inducing the device to execute further calculating a loading state of the device, wherein

the calculating the time-to-live includes calculating the time-to-live according to the calculated loading state.