Kabushiki Kaisha Toshiba

Kiyoko Sato

Toshio Shirakihara

Seiji Maeda

Hirokuni Yano

Takuya Hayashi

Nobuo Sakiyama

Tatsunori Kanai

Hideaki Hirayama

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.

Process migration method computer and system

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.

Storage device, backup method and computer program code of this storage device

Storage device, backup and fault tolerant redundant method and computer program code of plurality storage devices

A commit controlling scheme for a transaction processing in a system utilizing the check point/roll back scheme, which is capable of guaranteeing the reliability of data of the transaction processing even when the transaction processing and the check point/roll back scheme are employed simultaneously, is described. An issuance of an external output for notifying to a user that a transaction has been committed is delayed until after a new check point for the transaction processing process is generated by the fault recovery mechanism at a timing later than a commit of the transaction by the transaction processing process. This can be realized by delaying an issuance of a transaction commit notice from the transaction processing process, or by intercepting a transaction commit notice sent from the transaction processing process, or else by delaying an issuance of the external output by the client process after receiving a transaction commit notice from the transaction processing process.

Commit controlling scheme for transaction processing in system utilizing check point/roll back scheme

A process state management scheme capable of acquiring process states consistently even in a case where a new process is generated from some process, while using the synchronous checkpointing method. This scheme prohibits a new process generation during a process state acquisition, which can be realized by judging whether a process generation request by a first process for generating a second process is prior to a process state acquisition request or not, and generating the second process from the first process accordingly. This scheme also prohibits a process state acquisition during a new process generation, which can be realized by acquiring a process state at each of the first and second processes after a notice of the identifier of the second process from the first process is received, when a notice of the identifier of the second process from the second process is prior to the notice from the first process.

Method and system for process state management using checkpoints

A scheme for restarting processes at distributed checkpoints in a client-server computer system, in which a fault in one client computer does not affect the server computer and the other client computers. In this scheme, a fault occurring in one computer among of a plurality of computers constituting a client-server computer system is detected while these plurality of computers are executing respective processes, and whether that one computer in which the fault is detected is a server computer or not is judged. Then, related processes executed on these plurality of computers are restarted when that one computer is judged as the server computer, whereas no process executed on these plurality of computers is restarted when that one computer is not judged as the server computer. It is also possible to specify a restart information for each process indicating how processes should be restarted when a process fault occurs in each process, and to restart selected processes executed on these plurality of computers according to the restart information for a process in which the process fault is detected.

Growing community of inventors

Yokohama, Japan

Kiyoko Sato