摘要:
A computer-readable recording medium having recorded a hash-value generation program for calculating a hash value within a shorter period of processing time. When a target disk is specified for hash value calculation, a segment division block divides the target disk into fixed-length segments. A first hash-value calculation block applies a one-way hash function to all data in each segment to calculate a per-segment hash value. A second hash-value calculation block arranges the per-segment hash values in a segment order corresponding to the order of the data stored on the target disk and applies the one-way hash function again to the arranged per-segment hash values to calculate a total hash value. The hash value calculated in this manner is defined as a hash value of the target disk.
摘要:
A computer-readable recording medium having recorded a hash-value generation program for calculating a hash value within a shorter period of processing time. When a target disk is specified for hash value calculation, a segment division block divides the target disk into fixed-length segments. A first hash-value calculation block applies a one-way hash function to all data in each segment to calculate a per-segment hash value. A second hash-value calculation block arranges the per-segment hash values in a segment order corresponding to the order of the data stored on the target disk and applies the one-way hash function again to the arranged per-segment hash values to calculate a total hash value. The hash value calculated in this manner is defined as a hash value of the target disk.
摘要:
Upon receipt of a first key and first data, a control unit exercises control to store second data indicating a second key in association with the first key in a first node and to store the first data in association with the second key in a second node. Upon receipt of an access request that specifies the first key, the control unit detects that data stored in association with the first key is the second data, and accesses the first data stored in the second node on the basis of the second key indicated by the second data.
摘要:
A control unit shifts a boundary between a range of hash values allocated to a first node and a range of hash values allocated to a second node from a first hash value to a second hash value to thereby expand the range of hash values allocated to the first node. The control unit moves data which is part of data stored in the second node and in which hash values calculated from associated keys belong to a range between the first hash value and the second hash value, from the second node to the first node.
摘要:
A data management apparatus sends specific data and key information corresponding to the specific data to another apparatus, when executing a process to change a storage destination of the specific data in which the hash value obtained by applying a predetermined hash function to corresponding key information belongs to a certain range, from the data management apparatus to the other apparatus, and sends the identification information of the other apparatus stored in correspondence with the certain range to a request source of an operation request, when the operation request with respect to data corresponding to key information is received after the process.
摘要:
A data management apparatus sends specific data and key information corresponding to the specific data to another apparatus, when executing a process to change a storage destination of the specific data in which the hash value obtained by applying a predetermined hash function to corresponding key information belongs to a certain range, from the data management apparatus to the other apparatus, and sends the identification information of the other apparatus stored in correspondence with the certain range to a request source of an operation request, when the operation request with respect to data corresponding to key information is received after the process.
摘要:
A storage apparatus, method and program are provided. The apparatus includes a management information storing unit that stores management information which defines storage nodes to allocate primary data used as a destination of access and secondary data used as a backup. The apparatus also includes data allocation unit that divides storage nodes 5 into groups, and assigns data allocation destination so that the data allocation destination of the primary data and the data allocation destination of the secondary data with the same content as the primary data are not in the same group. The apparatus also includes an operation mode switching unit that replaces the role of primary data assigned to the storage node which belongs to the group subject to suspension with that of the secondary data that corresponds to the primary data.
摘要:
A storage system is disclosed that stores data across plural storage devices. The storage system includes plural modules. Each of the modules includes a storage device including a data storage section that has plural slice areas to store data elements one in each, and a control-information storage section that stores control information of the plural slice areas, a communications-function section having a function of sending and receiving the data elements stored in the slice areas in the data storage section. The modules communicate with each other to replicate the data element stored in the slice area into an unused slice area in another module so as to have data redundancy.
摘要:
A storage system is disclosed that stores data across plural storage devices. The storage system includes plural modules. Each of the modules includes a storage device including a data storage section that has plural slice areas to store data elements one in each, and a control-information storage section that stores control information of the plural slice areas, a communications-function section having a function of sending and receiving the data elements stored in the slice areas in the data storage section. The modules communicate with each other to replicate the data element stored in the slice area into an unused slice area in another module so as to have data redundancy.
摘要:
An internode put requesting unit detects a time-out with respect to a put request issued to the next node in the order of a multiplexing chain and notifies a put/get executing unit of the time-out. The put/get executing unit sends an error to the previous node in the order of the multiplexing chain or a client and instructs a put-failed-data synchronizing unit to synchronize data failed to be put, and the put-failed-data synchronizing unit performs a synchronization process. A primary makes other put requests wait until completion of the synchronization process. Furthermore, when having received the error, the client issues a get request to the tail end of the multiplexing chain.