METHOD AND SYSTEM FOR REPLICATING DATA IN A CLOUD STORAGE SYSTEM

• US 20150178364A1
• Filed: 07/23/2013
• Published: 06/25/2015
• Est. Priority Date: 07/23/2012
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Europe Ltd (NEC Corporation)
• Inventors: Dobre, Dan
• Granted Patent: US 10,445,338 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/184 implemented as replicated file system
• 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

Abstract

A method for replicating data in a cloud storage system supporting multiple clients, wherein the cloud storage system comprises a plurality of object storing entities (A, B, C) for storing data objects, includes requesting, by a client, values and associated timestamps for a first data object from a first quorum of the object storing entities (A, B, C). The method further includes determining, by the client, a most recent value of the first data object based on the associated timestamps. The method additionally includes performing, by the client, a compare-and-swap procedure, so that the determined value and its corresponding timestamp for the first data object updates the first data object with a value with a newer timestamp and stores the first data object in a second quorum of the object storing entities (A, B, C).

Claims

1. A method for replicating data in a cloud storage system supporting multiple clients, wherein the cloud storage system comprises a plurality of object storing entities for storing data objects, the method comprising:

requesting, by a client, values and associated timestamps for a first data object from a first quorum of the object storing entities,

determining, by the client, a most recent value of the first data object based on the associated timestamps, and

performing, by the client, a compare-and-swap procedure, so that)the determined value and its corresponding timestamp for the first data object updates the first data object with a value with a newer timestamp and stores the first data object in a second quorum of the object storing entities.

2. The method according to claim 1, wherein the method further comprises, before the determining a most recent value of the first data object based on the associated timestamps,

checking whether a second data object with a value with a more recent timestamp than the most recent value of the first data object exists, and, if yes,

using the value with the more recent timestamp, and the corresponding more recent timestamp for performing the compare-and-swap procedure.

3. The method according to claim 1, wherein the compare-and-swap procedure returns as a result old content of the first data object.

4. The method according to claim 1, wherein when the first data object is modified after the determining the most recent value of the first data object and before the performing the compare-and-swap procedure, performing the compare-and-swap procedure until at least one of:

the first data object is not modified anymore between two consecutive performances of the compare-and-swap procedure, or a quorum of the object storing entities reports values for the first data object whose corresponding timestamps are greater or equal than the timestamp of the determined most recent value of the first data object.

5. The method according to claim 1, wherein during the compare-and-swap procedure, additional responses of object storing entities not associated with the first quorum are included.

6. A system for replicating data in a cloud storage system. supporting multiple clients, wherein the cloud storage system comprises a plurality of object storing entities for storing data objects, the system comprising:

a client configured to;

request values and associated timestamps for a first data object from a first quorum of object storing entities,

determine a most recent value of the first data object based on the associated timestamps, and

perform a compare-and-swap procedure, so that the determined most recent value and its corresponding timestamp for the first data object updates the first data object with a value with a newer timestamp and stores the first data object in a second quorum of the object storing entities.