DISTRIBUTED STORAGE DEVICE, STORAGE NODE, DATA PROVIDING METHOD, AND MEDIUM

• US 20150347516A1
• Filed: 09/27/2013
• Published: 12/03/2015
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: YAMAKAWA, Satoshi, KOBAYASHI, Dai
• Granted Patent: US 9,870,402 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2228 Indexing structures
• CPC Class Codes: G06F 16/24568 Data stream processing; Continuous queries
• CPC Class Codes: G06F 16/24575 using context
• CPC Class Codes: G06F 16/248 Presentation of query results
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/9535 Search customisation based on user profiles and personalisation

Abstract

A distributed storage device according to the present invention includes: a plurality of storage nodes, the plurality of storage nodes includes: a data storage unit that accumulates stream data output from a device; a first time frame generation unit that generates a time frame synchronized with another storage node and associates a data element included in stream data accumulated in the data storage unit with one of time frames; a data selection unit that selects a data element associated with a predetermined time frame from the stream data accumulated in the data storage unit, based on an access request from a client terminal; and a data transmission unit that transmits a data element selected by the data selection unit to the client terminal.

Claims

1. A distributed storage device comprising:

a plurality of storage nodes,

the plurality of storage nodes comprising;

a data storage unit that accumulates stream data output from a device;

a first time frame generation unit that generates a time frame synchronized with another storage node and associates a data element included in stream data accumulated in the data storage unit with one of time frames;

a data selection unit that selects a data element associated with a predetermined time frame from the stream data accumulated in the data storage unit, based on an access request from a client terminal; and

a data transmission unit that transmits a data element selected by the data selection unit to the client terminal.

2. The distributed storage device according to claim 1, wherein

the data selection unit selects a data element associated with a time frame associated with the selected data element, as a data element with respect to a subsequent access request from the client terminal.

3. The distributed storage device according to claim 1, wherein

the data selection unit selects a data element associated with a time frame synchronized with a time frame associated with a data element selected by another storage node with respect to an access request from the client terminal, as a data element with respect to a subsequent access request from the client terminal.

4. The distributed storage device according to claim 1, wherein

the data selection unit selects a data element associated with a time frame by a predetermined number before a time frame on receiving an access request from the client terminal.

5. The distributed storage device according to claim 1, wherein

the data selection unit selects a latest data element included in the predetermined time frame.

6. The distributed storage device according to claim 1, wherein

the access request includes an identifier that identifies the client terminal.

7. The distributed storage device according to claim 1, comprising:

an inter-node synchronization unit that generates a request for updating a time frame, wherein

the first time frame generation unit generates a time frame depending on a request generated by the inter-node synchronization unit.

8. The distributed storage device according to claim 1, comprising:

an index server,

the index server comprising;

an index storage unit that accumulates an index with respect to stream data accumulated in a data storage unit of the plurality of storage nodes;

a second time frame generation unit that generates a time frame synchronized with the plurality of storage nodes and associates an index accumulated in the index storage unit with one of time frames; and

an index retrieval unit that selects an index associated with a predetermined time frame from indexes accumulated in the index storage unit, based on the access request transferred from one of storage nodes of the plurality of storage nodes, and transmits a selected index to the one of storage nodes, wherein

the plurality of storage nodes further comprising;

a data update unit that transmits stream data accumulated in the data storage unit to the index server; and

a data retrieval unit that transfers an access request from a client terminal to the index retrieval unit.

9. The distributed storage device according to claim 8, wherein

the data selection unit selects a data element associated with a time frame on an own storage node corresponding to a time frame on the index server associated with an index selected by the index retrieval unit with respect to an access request from a client terminal transferred to the index server, as a data element with respect to a subsequent access request from the client terminal.

10. The distributed storage device according to claim 8, wherein

the data selection unit selects a data element associated with a time frame on an own storage node corresponding to a time frame on the index server associated with an index selected by the index retrieval unit with respect to an access request from a client terminal transferred to the index server by another storage node, as a data element with respect to a subsequent access request from the client terminal.

11. A storage node that is one of a plurality of storage nodes included in a distributed storage device, comprising:

a data storage unit that accumulates stream data output from a device;

a first time frame generation unit that generates a time frame synchronized with another storage node and associates a data element included in stream data accumulated in the data storage unit with one of time frames;

a data selection unit that selects a data element associated with a predetermined time frame from the stream data accumulated in the data storage unit, based on an access request from a client terminal; and

a data transmission unit that transmits a data element selected by the data selection unit to the client terminal.

12. The storage node according to claim 11, wherein

the data selection unit selects a data element associated with a time frame associated with the selected data element, as a data element with respect to a subsequent access request from the client terminal.

13. The storage node according to claim 11, wherein

the data selection unit selects a data element associated with a time frame synchronized with a time frame associated with a data element selected by another storage node with respect to an access request from the client terminal, as a data element with respect to a subsequent access request from the client terminal.

14. The storage node according to claim 11, wherein

the distributed storage device comprising:

an inter-node synchronization unit that generates a request for updating a time frame, wherein

the first time frame generation unit generates a time frame depending on a request generated by the inter-node synchronization unit.

15. The storage node according to claim 11, wherein

the distributed storage device further comprising:

an index server, wherein

the index server comprising;

an index storage unit that accumulates an index with respect to stream data accumulated in a data storage unit of the plurality of storage nodes;

a second time frame generation unit that generates a time frame synchronized with the plurality of storage nodes and associates an index accumulated in the index storage unit with one of time frames; and

an index retrieval unit that selects an index associated with a predetermined time frame from indexes accumulated in the index storage unit, based on the access request transferred from one of storage node of the plurality of storage nodes, and transmits a selected index to the one of storage node, wherein

the storage node further comprising;

a data update unit that transmits stream data accumulated in the data storage unit to the index server; and

a data retrieval unit that transfers an access request from a client terminal to the index retrieval unit.

16. The storage node according to claim 15, wherein

the data selection unit selects a data element associated with a time frame on the storage node corresponding to a time frame on the index server associated with an index selected by the index retrieval unit with respect to an access request from a client terminal transferred to the index server, as a data element with respect to a subsequent access request from the client terminal.

17. The storage node according to claim 15, wherein

the data selection unit selects a data element associated with a time frame on the storage node corresponding to a time frame on the index server associated with an index selected by the index retrieval unit with respect to an access request from a client terminal transferred to the index server by another storage node, as a data element with respect to a subsequent access request from the client terminal.

18. A data providing method comprising:

accumulating stream data output from a device in a data storage unit by a storage node that is one of a plurality of storage nodes included in a distributed storage device;

generating a time frame synchronized with another storage node and associating a data element included in stream data accumulated in the data storage unit with one of time frames;

selecting a data element associated with a predetermined time frame from the stream data accumulated in the data storage unit, based on an access request from a client terminal; and

transmitting a selected data element to the client terminal.

19. The data providing method according to claim 18, wherein

the storage node selects a data element associated with a time frame associated with the selected data element, as a data element with respect to a subsequent access request from the client terminal.

20. The data providing method according to claim 18, wherein

the storage node selects a data element associated with a time frame synchronized with a time frame associated with a data element selected by another storage node with respect to an access request from the client terminal, as a data element with respect to a subsequent access request from the client terminal.

21. The data providing method according to claim 18, comprising:

transmitting stream data accumulated in the data storage unit to an index server by the storage node;

transferring an access request from the client terminal to the index server;

accumulating an index with respect to stream data accumulated in a storage unit of the plurality of storage nodes in an index storage unit by the index server;

generating a time frame synchronized with the plurality of storage nodes and associating an index accumulated in the index storage unit with one of time frames; and

selecting an index associated with a predetermined time frame from indexes accumulated in the index storage unit, based on an access request from the client terminal transferred from one of storage nodes of the plurality of storage nodes, and transmitting a selected index to the one of storage nodes.

22. The data providing method according to claim 21, wherein

the storage node selects a data element associated with a time frame on an own storage node corresponding to a time frame on the index server associated with an index selected by the index server with respect to an access request from the client terminal transferred to the index server, as a data element with respect to a subsequent access request from the client terminal.

23. The data providing method according to claim 21, wherein

the storage node selects a data element associated with a time frame on the storage node corresponding to a time frame on the index server associated with an index selected by the index server with respect to an access request from the client terminal transferred to the index server by another storage node, as a data element with respect to a subsequent access request from the client terminal.

24. A computer readable non-transitory medium embodying a program, the program causing storage node included in a distributed storage device to perform a method, the method comprising:

accumulating stream data output from a device in a data storage unit;

generating a time frame synchronized with another storage node and associating a data element included in stream data accumulated in the data storage unit with one of time frames;

selecting a data element associated with a predetermined time frame from the stream data accumulated in the data storage unit, based on an access request from a client terminal; and

transmitting a selected data element to the client terminal.

25. The method according to claim 24, further comprising:

selecting a data element associated with a time frame associated with the selected data element, as a data element with respect to a subsequent access request from the client terminal.

26. The method according to claim 24, further comprising:

selecting a data element associated with a time frame synchronized with a time frame associated with a data element selected by another storage node with respect to an access request from the client terminal, as a data element with respect to a subsequent access request from the client terminal.

27. A distributed storage device comprising:

a plurality of storage nodes,

the plurality of storage nodes comprising;

a data storage means for accumulating stream data output from a device;

a first time frame generation means for generating a time frame synchronized with another storage node and associates a data element included in stream data accumulated in the data storage unit with one of time frames;

a data selection means for selecting a data element associated with a predetermined time frame from the stream data accumulated in the data storage unit, based on an access request from a client terminal; and

a data transmission means for transmitting a data element selected by the data selection unit to the client terminal.