REMOTE REDUNDANT ARRAY OF INEXPENSIVE MEMORY

• US 20140101397A1
• Filed: 10/05/2012
• Published: 04/10/2014
• Est. Priority Date: 10/05/2012
• Status: Abandoned Application

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Shribman, Aidan, Hudzia, Benoit, Izsak, Peter, Tell, Roei
• Application Number:
  US13/646,433
• Publication Number:
  US 20140101397A1
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A method for retrieving stored information from a storage node includes operating a computing device to generate a memory access request comprising a virtual memory address that identifies a first storage node and at least a second storage node based on the virtual memory address. The method further includes operating the computing device to transmit a retrieve request to both the first storage node and the second storage node to retrieve stored information. The first and the second storage nodes are each enabled to store a copy of the stored information, and are included in a plurality of storage nodes that constitute an extended memory. If a first response from the first storage node is received before a second response is received from the second storage node, then the method further includes operating the computing devices to receive the stored information from the first storage node.

Claims

1. A method for retrieving stored information from a storage node, the method comprising operating a computing device to perform steps of:

generating a memory access request comprising a virtual memory address that identifies a first storage node and at least a second storage node based on the virtual memory address;

transmitting a retrieve request to both the first storage node and said at least second storage node to retrieve stored information from the first storage node or said at least second storage node, wherein the first storage node and said at least second storage node are each enabled to store a copy of the stored information, and wherein the first storage node and said at least second storage node are included in a plurality of storage nodes that constitute an extended memory; and

if a first response from the first storage node is received before a second response is received from said at least second storage node, then receiving the stored information from the first storage node.

2. The method of claim 1, further comprising, if the second response is received after the first response is received, then disregarding the second response.

3. The method of claim 1, wherein if said at least second storage node does not respond to the retrieval request, then determining whether said at least second storage node has failed, and replacing said at least second storage node with a replacement storage node from the plurality of storage nodes if said at least second storage node has failed.

4. The method of claim 3, wherein replacing said at least second storage node with the replacement storage node includes transmitting a listen request to the replacement storage node to listen for storage requests to store information that is associated with the listen request.

5. The method of claim 4, wherein replacing said at least second storage node with the replacement storage node further includes transmitting a duplication request to the first storage node to transmit information stored in the first storage node to the replacement storage node.

6. The method of claim 3, further comprising storing first information in a status table that identifies said at least second storage node as a failed node.

7. The method of claim 6, further comprising storing second information in the status table that identifies the replacement storage node as replacement node for said at least second storage node.

8. The method of claim 1, wherein each of the storage nodes comprises a server that includes random access memory, and the random access memories of the plurality of storage nodes constitute the extended memory that is addressable via the virtual memory address.

9. A non-transitory computer-readable storage medium comprising instructions for retrieving stored information from a storage node, wherein the instructions, when executed, are for controlling a computing device to be configured for:

generating a memory access request comprising a virtual memory address that identifies a first storage node and at least a second storage node based on the virtual memory address;

transmitting a retrieve request to both the first storage node and said at least second storage node to retrieve stored information from the first storage node or said at least second storage node, wherein the first storage node and said at least second storage node are each enabled to store a copy of the stored information, and wherein the first storage node and said at least second storage node are included in a plurality of storage nodes that constitute an extended memory; and

if a first response from the first storage node is received before a second response is received from said at least second storage node, then receiving the stored information from the first storage node.

10. The non-transitory computer-readable storage medium of claim 9, wherein if said at least second storage node does not respond to the retrieval request, then the instructions, when executed, are for further controlling the computing device to be configured for ascertaining whether said at least second storage node has failed, and for replacing said at least second storage node with a replacement storage node from the plurality of storage nodes if said at least second storage node has failed.

11. The non-transitory computer-readable storage medium of claim 10, wherein replacing said at least second storage node with the replacement storage node includes transmitting a listen request to the replacement storage node to listen for storage requests to store information that is associated with the storage request.

12. The non-transitory computer-readable storage medium of claim 11, wherein replacing said at least second storage node with the replacement storage node further includes transmitting a duplication request to the first storage node to transmit information stored in the first storage node to the replacement storage node.

13. The non-transitory computer-readable storage medium of claim 10, wherein the instructions, when executed, are for controlling a computing device to be configured for storing first information in a status table that identifies the second storage node as a failed node.

14. The non-transitory computer-readable storage medium of claim 13, wherein the instructions, when executed, are for controlling a computing device to be configured for storing second information in the status table that identifies the replacement storage node as replacement node for the second storage node.

15. A computing device for retrieving stored information from a storage node, the computing device comprising:

a processor; and

a computer-readable storage medium comprises instructions for controlling the processor to be configured for;

generating a memory access request comprising a virtual memory address that identifies a first storage node and at least a second storage node based on the virtual memory address;

transmitting a retrieve request to both the first storage node and said at least second storage node to retrieve stored information from the first storage node or said at least second storage node, wherein the first storage node and said at least second storage node are each enabled to store a copy of the stored information, and wherein the first storage node and said at least second storage node are included in a plurality of storage nodes that constitute an extended memory; and

if a first response from the first storage node is received before a second response is received from the at least second storage node, then receiving the stored information from the first storage node.

16. The computing device of claim 15, wherein if said at least second storage node does not respond to the retrieval request, then the computer-readable storage medium comprises instructions for further controlling the processor to be configured for ascertaining whether said at least said second storage node has failed and for replacing said at least second storage node with a replacement storage node from the plurality of storage nodes if said at least second storage node has failed.

17. The computing device of claim 16, wherein replacing said at least second storage node with the replacement storage node includes transmitting a listen request to the replacement storage node to listen for storage requests to store information that is associated with the storage request.

18. The computing device of claim 17, wherein replacing said at least second storage node with the replacement storage node further includes transmitting a duplication request to the first storage node to transmit information stored in the first storage node to the replacement storage node.

19. The computing device of claim 16, wherein the computer-readable storage medium comprises instructions for further controlling the processor to be configured for storing first information in a status table that identifies the second storage node as a failed node.

20. The computing device of claim 19, wherein the computer-readable storage medium comprises instructions for further controlling the processor to be configured for storing second information in the status table that identifies the replacement storage node as replacement node for the second storage node.