Abstract: An information processing system performs a real-time operation periodically at specific time intervals. The system includes a unit for performing a scheduling operation of assigning the real-time operation to a processor to perform the real-time operation periodically at the specific time intervals by the processor, a unit for computing a ratio of an execution time of the real-time operation to be performed by the processor at a first operating speed, based on the specific time intervals and cost information concerning a time required to perform the real-time operation by the processor at the first operating speed, and a unit for performing an operating speed control operation to operate the processor at a second operating speed that is lower than the first operating speed, the second operating speed being determined based on the computed ratio.

Abstract: An information processing system performs a real-time operation including a combination of a plurality of tasks. The system includes a plurality of processors, a unit which stores structural description information and a plurality of programs describing procedures corresponding to the tasks, the structural description information indicating a relationship in input/output between the programs and including cost information concerning time required for executing each of the programs, a unit which determines an execution start timing and execution term of each of a plurality of threads for execution of the programs based on the structural description information, and a unit which performs a scheduling operation of assigning the threads to at least one of the processors according to a result of the determining.

Abstract: An information processing system performs a real-time operation including a combination of a plurality of tasks. The system includes a plurality of processors, a unit which stores structural description information and a plurality of programs describing procedures corresponding to the tasks, the structural description information indicating a relationship in input/output between the programs and including cost information concerning time required for executing each of the programs, a unit which determines an execution start timing and execution term of each of a plurality of threads for execution of the programs based on the structural description information, and a unit which performs a scheduling operation of assigning the threads to at least one of the processors according to a result of the determining.

Abstract: Process migration method includes copying first process context indicative of first processing, transmitting process context to second computer, causing first computer to start generation of first execution record, causing second computer to receive process context, determining, from first execution record, whether first processing should be migrated, if it is determined that first processing should postpone being migrated, finishing generation of first execution record, starting generation of second execution record, transmitting first execution record to second computer, reproducing process context, and determining, from second execution record, whether first processing should be migrated, after reproducing of process context is finished in the second computer.

Abstract: A transactional file system configured to realize atomic update of plural files by transactions. In the transactional file system, a log entry containing information for validating all updates made by a transaction collectively on a stable memory device, is generated for one or more files updated on a buffer region by the transaction since a start of a processing of the transaction until a commit of the transaction. Then, the log entry is written into the stable memory device at a time of the commit of the transaction.

Abstract: Process migration method includes copying first process context indicative of first processing, transmitting process context to second computer, causing first computer to start generation of first execution record, causing second computer to receive process context, determining, from first execution record, whether first processing should be migrated, if it is determined that first processing should postpone being migrated, finishing generation of first execution record, starting generation of second execution record, transmitting first execution record to second computer, reproducing process context, and determining, from second execution record, whether first processing should be migrated, after reproducing of process context is finished in the second computer.

Abstract: A scheme for systematically registering meta-data with respect to various types of individual data so as to enable sophisticated retrieval or application program construction assistance utilizing the meta-data in a data server is disclosed. A data type of registering data to be registered into a data server that registers and manages data and meta-data for data, and one procedure corresponding to the detected data type is selected from a plurality of procedures provided in correspondence to respective data types and stored in advance, each procedure having a program code for generating the meta-data for data according to a corresponding data type. Then, the meta-data for the registering data are generated by executing the program code of the selected procedure, and the generated meta-data are registered in relation to the registering data.

Abstract: A storage device for which restoration of data is possible without the need for excess equipment includes mirrored storage units for online use and for backup, and is capable of performing a data backup while continuing input and output of data. The storage device is further provided with an update data storage unit for storing update data. According to the storage device, even if the information stored in a storage unit for online use is not capable of being read because of a fault in the storage unit, it is possible to restore the data in the backup storage unit to the state that existed in the storage unit for online use immediately before the fault by applying the update data to the information stored in the storage device for backup.

Abstract: A scheme for systematically registering meta-data with respect to various types of individual data so as to enable sophisticated retrieval or application program construction assistance utilizing the meta-data in a data server is disclosed. A data-type of registering data to be registered into a data server that registers and manages data and meta-data for data, and one procedure corresponding to the detected data type is selected from a plurality of procedures provided in correspondence to respective data types and stored in advance, each procedure having a program code for gene rating the meta-data for data according to a corresponding data type. Then, the meta-data for the registering data are generated by executing the program code of the selected procedure, and the generated meta-data are registered in relation to the registering data.

Abstract: A scheme for systematically registering meta-data with respect to various types of individual data so as to enable sophisticated retrieval or application program construction assistance utilizing the meta-data in a data server is disclosed. A data type of registering data to be registered into a data server that registers and manages data and meta-data for data, and one procedure corresponding to the detected data type is selected from a plurality of procedures provided in correspondence to respective data types and stored in advance, each procedure having a program code for generating the meta-data for data according to a corresponding data type. Then, the meta-data for the registering data are generated by executing the program code of the selected procedure, and the generated meta-data are registered in relation to the registering data.

Abstract: A storage device for which restoration of data is possible without the need for excess equipment includes mirrored storage units for online use and for backup, and is capable of performing a data backup while continuing input and output of data. The storage device is further provided with an update data storage unit for storing update data. According to the storage device, even if the information stored in a storage unit for online use is not capable of being read because of a fault in the storage unit, it is possible to restore the data in the backup storage unit to the state that existed in the storage unit for online use immediately before the fault by applying the update data to the information stored in the storage device for backup.

Abstract: An information processing system performs a plurality of tasks within a specific time interval. The system includes a bus, a plurality of processors which transfer data via the bus, and a unit for performing a scheduling operation of determining execution start timing of each of the tasks and at least one the processors which executes the tasks, based on cost information concerning a time required to perform each of the tasks and bandwidth information concerning a data transfer bandwidth required by each of the tasks, to perform the tasks within the specific time interval without overlapping execution terms of at least two tasks of the tasks, the two tasks requiring data transfer bandwidths not less than those of the others of the tasks.

Abstract: A storage device for which restoration of data is possible without the need for excess equipment includes mirrored storage units for online use and for backup, and is capable of performing a data backup while continuing input and output of data. The storage device is further provided with an update data storage unit for storing update data. According to the storage device, even if the information stored in a storage unit for online use is not capable of being read because of a fault in the storage unit, it is possible to restore the data in the backup storage unit to the state that existed in the storage unit for online use immediately before the fault by applying the update data to the information stored in the storage device for backup.

Abstract: An information processing system performs a real-time operation periodically at specific time intervals. The system includes a unit for performing a scheduling operation of assigning the real-time operation to a processor to perform the real-time operation periodically at the specific time intervals by the processor, a unit for computing a ratio of an execution time of the real-time operation to be performed by the processor at a first operating speed, based on the specific time intervals and cost information concerning a time required to perform the real-time operation by the processor at the first operating speed, and a unit for performing an operating speed control operation to operate the processor at a second operating speed that is lower than the first operating speed, the second operating speed being determined based on the computed ratio.

Abstract: An information processing system periodically performs a real-time operation including a plurality of chained tasks. The system includes a plurality of processors, a unit for dividing the chained tasks into a first task group and a second task group based on a relationship in order of execution among the tasks, the second task group being executed after the first task group, and a unit for performing a scheduling operation of periodically assigning each of the first task group and the second task group to at least one of the processors to periodically execute the first task group at regular time intervals and periodically execute the second task group at the regular time intervals with a one-period delay relative to the first task group.

Abstract: A real-time processing system that executes a plurality of threads, each of the threads being a unit of execution of a real-time operation, comprises a plurality of processors, a unit which selects a tightly coupled thread group from among the threads based on coupling attribute information indicative of a coupling attribute between the threads, the tightly coupled thread group including a set of tightly coupled threads running in cooperation with each other, and a unit which performs a scheduling operation of dispatching the tightly coupled threads to several of the processors that are equal to the tightly coupled threads to simultaneously execute the tightly coupled threads by the several of the processors.

Abstract: An information processing system performs a real-time operation including a combination of a plurality of tasks. The system includes a plurality of processors, a unit which stores structural description information and a plurality of programs describing procedures corresponding to the tasks, the structural description information indicating a relationship in input/output between the programs and including cost information concerning time required for executing each of the programs, a unit which determines an execution start timing and execution term of each of a plurality of threads for execution of the programs based on the structural description information, and a unit which performs a scheduling operation of assigning the threads to at least one of the processors according to a result of the determining.

Abstract: A transaction processing system capable of easily and efficiently realizing the file update processing by a plurality of transactions operating in parallel as well as the recovery processing at a time of a fault occurrence is disclosed. In the transaction processing system, a plurality of transactions that carry out update processing with respect to one file read out onto a buffer region are executed, and that one file is written into a stable memory device at a time of commit of one transaction among the plurality of transactions, where that one file contains a content of committed updates made by that one transaction and a content of non-committed updates made by other non-committed transactions, and information for cancelling the non-committed updates.

Abstract: A transactional file system which is capable of realizing atomic update of plural files by transactions is disclosed. In the transactional file system, a log entry containing an information for validating all updates made by a transaction collectively on a stable memory device, is generated for one or more files updated on a buffer region by the transaction since a start of a processing of the transaction until a commit of the transaction. Then, the log entry is written into the stable memory device at a time of the commit of the transaction.

Abstract: A hierarchical memory scheme capable of improving a hit rate for the segment containing the random access point rather than improving the overall hit rate of the cache, and a data playback scheme capable of automatically detecting positions that are potentially used as playback start indexes by the user and attaching indexes, are disclosed. The hierarchical storage device stores random access point segment information from which a possibility for each segment to contain a point that can potentially be random accessed in future can be estimated, and controls a selection of the selected segments to be stored in the cache storage device according to the random access point segment information.