Distributed storage system, and data-access method therefor
First Claim
1. A distributed storage system including a plurality of storage systems coupled with one another via a network, a first storage system among the plurality of storage systems comprising:
- a strong-consistency-control processing unit which, during access to duplicated data stored in the distributed storage system, controls data synchronization that ensures the consistency of the duplicated data that the accessed duplicated data is the latest;
a weak-consistency-control processing unit which, during access to the duplicated data, controls data synchronization that does not necessarily ensure the consistency of the duplicated data;
an access-switching processing unit which;
in response to an I/O request for the duplicated data, determines, in accordance with policies predetermined in accordance with characteristics of the duplicated data, a redundancy number corresponding to the number of second storage systems to have the duplicated data stored thereon;
selects, from among the plurality of storage systems, in accordance with the characteristics of the duplicated data and a position of a terminal issuing the I/O request, second storage systems of a number corresponding to the redundancy number; and
selectively determines via an access-switching policy and a policy template that correspond to the I/O request, as the control for the data synchronization, one from among a strong-consistency-control scheme, a weak-consistency-control scheme, and an unnecessary consistency control scheme, wherein the policy templates include information regarding the consistency used for determining the control for the data synchronization, the access response, and the redundancy number;
wherein the unnecessary consistency control scheme, consistency and redundancy of the I/O target data is unnecessary, because the I/O processing can be performed on the respective storage systems without executing consistency processing; and
an I/O processing unit which executes, on the basis of the determined control for the data synchronization, the I/O request for the duplicated data in the selected second storage systems.
1 Assignment
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Accused Products
Abstract
Each of a plurality of storage systems in a distributed storage system is provided with: a strong-consistency-control processor which controls data synchronization that ensures consistency of duplicated data; a weak-consistency-control processor which controls data synchronization that does not necessarily ensure consistency of the duplicated data; an access-switching processor which determines a redundancy number corresponding to the number of storage systems having duplicated data stored thereon, selects in accordance with the characteristics of the duplicated data and the position of a terminal issuing the I/O request, storage systems of a number corresponding to the redundancy number, and selectively determines, as the control for the data synchronization, one from among the strong-consistency-control processor, the weak-consistency-control processor, and consistency control unnecessary; and an I/O processor which executes, on the basis of the determined control for the data synchronization, the I/O request for the duplicated data in the selected storage systems.
7 Citations
14 Claims
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1. A distributed storage system including a plurality of storage systems coupled with one another via a network, a first storage system among the plurality of storage systems comprising:
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a strong-consistency-control processing unit which, during access to duplicated data stored in the distributed storage system, controls data synchronization that ensures the consistency of the duplicated data that the accessed duplicated data is the latest; a weak-consistency-control processing unit which, during access to the duplicated data, controls data synchronization that does not necessarily ensure the consistency of the duplicated data; an access-switching processing unit which; in response to an I/O request for the duplicated data, determines, in accordance with policies predetermined in accordance with characteristics of the duplicated data, a redundancy number corresponding to the number of second storage systems to have the duplicated data stored thereon; selects, from among the plurality of storage systems, in accordance with the characteristics of the duplicated data and a position of a terminal issuing the I/O request, second storage systems of a number corresponding to the redundancy number; and selectively determines via an access-switching policy and a policy template that correspond to the I/O request, as the control for the data synchronization, one from among a strong-consistency-control scheme, a weak-consistency-control scheme, and an unnecessary consistency control scheme, wherein the policy templates include information regarding the consistency used for determining the control for the data synchronization, the access response, and the redundancy number; wherein the unnecessary consistency control scheme, consistency and redundancy of the I/O target data is unnecessary, because the I/O processing can be performed on the respective storage systems without executing consistency processing; and an I/O processing unit which executes, on the basis of the determined control for the data synchronization, the I/O request for the duplicated data in the selected second storage systems. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A data access method in a distributed storage system including a plurality of storage systems coupled with one another via a network,
wherein a first storage system among the plurality of storage systems performs the steps of: -
determining, in response to an I/O request for the duplicated data and in accordance with policies predetermined in accordance with characteristics of the duplicated data, a redundancy number corresponding to a number of second storage systems to have the duplicated data stored thereon; selecting, from among the plurality of storage systems, in accordance with the characteristics of the duplicated data and a position of a terminal issuing the I/O request, second storage systems of a number corresponding to the redundancy number; selectively determining via an access-switching policy and a policy template that correspond to the I/O request, as the control for the data synchronization, one from among (1) strong consistency control scheme which, during access to the duplicated data stored in the distributed storage system, controls data synchronization that ensures the consistency of the duplicated data that the accessed duplicated data is the latest, (2) weak consistency control scheme which, during access to the duplicated data, controls data synchronization that does not necessarily ensure the consistency of the duplicated data, and (3) an unnecessary consistency control scheme, wherein the policy templates include information regarding the consistency used for determining the control for the data synchronization, the access response, and the redundancy number; wherein the unnecessary consistency control scheme, consistency and redundancy of the I/O target data is unnecessary, because the I/O processing can be performed on the respective storage systems without executing consistency processing; and executing, on the basis of the determined control for the data synchronization, the I/O request for the duplicated data in the selected second storage systems. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification