Abstract: Disclosed is a method of calculating parity. The method dividing, by a client system, a file which is to be stored into chunks of a preset size and distributively storing the chunks in a plurality of data servers; sending, by the client system, a data write complete notification message to a metadata server; storing, by the metadata server, a file sent through the data write complete notification message in a recovery queue; and sending, by the metadata server, a random data server a parity calculation request for the file stored in the recovery queue.

Abstract: Disclosed are an apparatus, a system, and a method for recovering meta data using fragmentary information. The system for recovering meta data includes: a data server storing recovery information for recovering at least one data file and meta data related to each of the data file; and a meta data server storing the meta data related to the data files and receiving the recovery information from the data server when the meta data are lost to recover the lost meta data. By this configuration, the exemplary embodiment of the present invention stably can the lost meta data of the meta data server by using the recovery the meta data and prevent the phenomenon that the meta data collides with each other on the same directory hierarchical structure.

Abstract: The present invention relates to an apparatus and method of performing an error recovery process in an asymmetric clustering file system that has higher efficiency in data recovery when a data server in an asymmetric clustering file system fails than a method of processing the data recovery in the metadata server. The present invention includes receiving a chunk list requiring recovery by a data server included in the other data server groups than a data server group including a failed data server among a plurality of data server groups, requesting chunk data necessary for recovering an erroneous chunk from a data server in the other data server groups to the other data servers than the failed data server in the data server group, and recovering the erroneous chunk based on the chunk data by the data server in the other data server group.

Abstract: A remote power management technology for a cluster system of the present invention can monitor and control the power status of multiple hosts of the cluster system individually, thereby decreasing power consumption of the cluster system. A remote power management system includes a plurality of management nodes, a power proxy server, and a power management server. The management nodes, which manage power of the hosts of the cluster system respectively, are divided into groups. The power proxy server manages each group, monitors the power status of each management node of the group to generate proxy monitoring information, and transmits a power setting command to the management node of the specific host requiring power setting. The power management server monitors the power status of the hosts using the proxy monitoring information and transmits the power setting command to the power proxy server of the group including the management node of the specific host.

Abstract: Disclosed is a method of calculating parity. The method dividing, by a client system, a file which is to be stored into chunks of a preset size and distributively storing the chunks in a plurality of data servers; sending, by the client system, a data write complete notification message to a metadata server; storing, by the metadata server, a file sent through the data write complete notification message in a recovery queue; and sending, by the metadata server, a random data server a parity calculation request for the file stored in the recovery queue.

Abstract: Disclosed is a cloud storage managing a plurality of files, including: a plurality of metadata servers managing a plurality of metadata associated with the plurality of files; a plurality of data servers managing the data of the plurality of files; and a cluster management server managing the plurality of metadata servers and the plurality of data servers.

Abstract: Provided are a data transmitting device transmitting data through a delay insensitive data transmitting method and a data transmitting method. The data transmitting device and the data transmitting method use the delay insensitive data transmitting method supporting a 2-phase hand shake protocol. During data transmission, data are encoded into three logic state having no space state through a ternary encoding method. According to the data transmitting device and the data transmitting method, data are stably transmitted to a receiver regardless of the length of a wire, and provides more excellent performance in an aspect of a data transmission rate, compared to a related art 4-phase delay data transmitting method.

Abstract: Disclosed are an apparatus, a system, and a method for recovering meta data using fragmentary information. The system for recovering meta data includes: a data server storing recovery information for recovering at least one data file and meta data related to each of the data file; and a meta data server storing the meta data related to the data files and receiving the recovery information from the data server when the meta data are lost to recover the lost meta data. By this configuration, the exemplary embodiment of the present invention stably can the lost meta data of the meta data server by using the recovery the meta data and prevent the phenomenon that the meta data collides with each other on the same directory hierarchical structure.

Abstract: Provided is a hot data management method based on hit counter, which prevents loads from being concentrated on a specific data server due to hot data by efficiently managing the hot data in the asymmetric storage system. Each of data servers of an asymmetric storage system checks hit counter for data stored in the corresponding data server to maintain hit counter information on the data in a latest state. The data server transmits the hit counter information to a metadata server at predetermined intervals. The data server makes or deletes a copy of the data according to the determination of the metadata server whether the data is hot data.

Abstract: An adaptive mobile cloud system using a private virtual instance (PVI) includes: a PVI automatic provisioning for generating a PVI by providing a hardware resource, an operating system and an application which are requested by a user terminal; a PVI image manager for storing and managing an image of an execution state of the PVI by checking a state of the PVI; a mobile interface adaptor that is adaptively operated according to an input/output device and resources of the user terminal; and an adaptive application manager for executing an application by adaptive cooperation between the user terminal and the PVI according to the resource of the user terminal.

Abstract: The present invention relates to an apparatus and method of performing an error recovery process in an asymmetric clustering file system that has higher efficiency in data recovery when a data server in an asymmetric clustering file system fails than a method of processing the data recovery in the metadata server. The present invention includes receiving a chunk list requiring recovery by a data server included in the other data server groups than a data server group including a failed data server among a plurality of data server groups, requesting chunk data necessary for recovering an erroneous chunk from a data server in the other data server groups to the other data servers than the failed data server in the data server group, and recovering the erroneous chunk based on the chunk data by the data server in the other data server group.

Abstract: Provided are an apparatus and a method which can be easily implemented with flexibility enabling distributing all metadata of trees and files in an asymmetric distributed file system. The apparatus includes: a metadata storage unit storing metadata corresponding to a part of partitions of a virtual metadata address space storing metadata for directories and/or files for each of the partitions; and a metadata storage management unit controlling the metadata so that the metadata are stored in the metadata storage unit and manages a master map including information on the part of the partitions. Since all directories and files can be distributed to a plurality of metadata servers without a limitation, it is possible to prevent a load from being concentrated on a predetermined metadata server. Metadata roles of the metadata servers are very simply readjusted and as a result, the load can be easily distributed in a partition level.

Abstract: Provided is a data processing method in an asymmetric cluster filesystem. Each data server pre-allocates a free data block and transmits relevant information to a metadata server. The metadata server allocates a free data block and generates metadata by using free data block information, which is received beforehand and managed, upon a user's request of data generation. Then, the data server records the data on the free data block indicated in the metadata. Accordingly, network cost and operation amount of a server decrease and the load can be fairly distributed.

Abstract: A metadata server in an asymmetric cluster file system detects the used capacity and the free capacity of a disk volume in a data server to allocate chucks. The method for selecting a disk volume includes receiving status information from a data server periodically and adjusting the standby command number of a disk volume in the disk server on the basis of the status information, and selecting a disk volume for chunk allocation on the basis of the standby command number in response to a chunk allocation request from a client.

Abstract: Provided are a metadata server cluster and a metadata management method thereof, which distribute metadata for a file to a cluster including a plurality of metadata servers to replicate the metadata. The metadata server includes a directory hierarchy storage unit, a metadata storage unit, and a search unit. The directory hierarchy storage unit stores all directory hierarchies which are stored in the metadata server cluster. The metadata storage unit stores metadata for a data file. The search unit searches the directory hierarchies and the metadata.

Abstract: Provided is a hot data management method based on hit counter, which prevents loads from being concentrated on a specific data server due to hot data by efficiently managing the hot data in the asymmetric storage system. Each of data servers of an asymmetric storage system checks hit counter for data stored in the corresponding data server to maintain hit counter information on the data in a latest state. The data server transmits the hit counter information to a metadata server at predetermined intervals. The data server makes or deletes a copy of the data according to the determination of the metadata server whether the data is hot data.

Abstract: Provided is a TOE hardware which includes intrusion prevention system hardware for inspection and real-time interrupt against static/dynamic attacks over network as well as fast TCP/IP processing, and a packet processing method in the TOE hardware. When a network packet is received, it is segmented to extract a header and a payload. A pattern matching inspection is performed for the payload, and the payload passed the inspection is transferred to the host. For the header, a header inspection is performed and a TCP/IP processing is performed on the header passed the inspection. Processing on the payload is performed in parallel with processing on the header. Accordingly, the packet processing speed of the TOE hardware increases.

Abstract: A remote power management technology for a cluster system of the present invention can monitor and control the power status of multiple hosts of the cluster system individually, thereby decreasing power consumption of the cluster system. A remote power management system includes a plurality of management nodes, a power proxy server, and a power management server. The management nodes, which manage power of the hosts of the cluster system respectively, are divided into groups. The power proxy server manages each group, monitors the power status of each management node of the group to generate proxy monitoring information, and transmits a power setting command to the management node of the specific host requiring power setting. The power management server monitors the power status of the hosts using the proxy monitoring information and transmits the power setting command to the power proxy server of the group including the management node of the specific host.

Abstract: Provided are a data transmitting device transmitting data through a delay insensitive data transmitting method and a data transmitting method. The data transmitting device and the data transmitting method use the delay insensitive data transmitting method supporting a 2-phase hand shake protocol. During data transmission, data are encoded into three logic state having no space state through a ternary encoding method. According to the data transmitting device and the data transmitting method, data are stably transmitted to a receiver regardless of the length of a wire, and provides more excellent performance in an aspect of a data transmission rate, compared to a related art 4-phase delay data transmitting method.

Abstract: A method and system for processing sensor data in a context-aware system is provided. The system includes: a sensor service collecting the sensor data from a driver of a physical sensor and generating a low level event; an STHQ temporarily storing the generated event and an event generated previously by an event interceptor; and a sensor framework comprised of the event interceptor forming an EIC (event interpretation chain) which interprets the generated event and the event stored in the STHQ and generated previously in connection with each other, and generating or deleting an event or processing the generated event as an event necessary for an upper level application service through an interlocking with the STHQ. The present invention provides active services on the basis of context knowledge inputted from various sensors.