Computer-implemented methods and systems are provided for detecting a failed server. The computer-implemented method includes detecting a plurality of servers within a network, allowing each of the plurality of servers to monitor a state of other servers of the plurality of servers, and in response to detecting a failed server, allowing another server of the plurality of servers to complete remaining work of the failed server.

Examples may include intercepting packets outputted from a primary virtual machine (PVM) hosted by a first server and converting one or more fields of protocol headers for each intercepted packet such that output-packet-similarity may be increased between the PVM outputted packets and packets outputted by a secondary virtual machine (SVM) hosted by a second server.

According to an aspect of the invention, a computerised system, in particular control system is provided, which is configured, from an input vector (I.sub.n) which represents a discrete number of input variables and from a state vector (Z.sub.n) which represents a discrete number of state variables, to determine a new state vector (Z.sub.n+1) whose state variables are updated, as well as an output vector (O.sub.n) which represents a discrete number of output variables, wherein the output variables are provided for controlling at least one appliance and/or for outputting information. The system comprises a plurality of computation units which in parallel determine the new state vector and the output vector from the input vector and the state vector. According to the invention, the system is configured such that at least all news state vectors are exchanged between the computation units after each cycle.

A module health system includes a module health circuit comprising a hardware register that is set to a first value in response to the system starting, an application register that is set to the first value in response to the system starting and a watchdog timer register that is set to the first value in response to the system starting. The system further includes a power on self-test that determines whether the system has passed a plurality of tests and that selectively sets the hardware register to a second value based on the determination, an external software application that determines whether a safety critical system is healthy and selectively sets the application register based on the determination, a watchdog timer application that selectively sets the watchdog timer register, a central processing unit that determines whether to de-assert a module health signal.

A nuclear power plant control system including: a detection unit for detecting a specific event occurring in the nuclear power plant; an on-site equipment handling the event; and a majority decision judging device and an on-site equipment control device which constitute a plurality of control devices respectively operating independently. Each of the control devices includes a plurality of arithmetic units which perform arithmetic processes independently and in parallel based on a detection result of the detection unit, and output a signal for controlling the on-site equipment according to the results of operations of the arithmetic processes. The plurality of arithmetic units perform a matching process for harmonizing process statuses of the arithmetic processes of respective arithmetic units with each other when starting up the control devices, and after completing the matching process, respectively perform the arithmetic processes independently and in parallel.

Computer-implemented methods and systems are provided for detecting a failed server. The computer-implemented method includes creating a proxy file for each server of a plurality of servers in an active state and assigning a timestamp to each proxy file of each server of the plurality of servers. The computer-implemented method further includes permitting each server to inspect each timestamp of each proxy file of each server of the plurality of servers and determining whether the timestamp assigned to each proxy file of each server of the plurality of servers exceeds a predetermined threshold. The computer-implemented method further includes, in response to a timestamp of a proxy file of a failed server exceeding the predetermined threshold, allowing another server of the plurality of servers to complete remaining work of the failed server.

A graphics processing system includes a plurality of processing units, wherein the graphics processing system is configured to process a task first and second times at the plurality of processing units. Data identifying which processing unit of the plurality of processing units the task has been allocated to is consulted on allocating the task to a processing unit for processing for a second time, and, in response, the task is allocated for processing for the second time to any processing unit of the plurality of processing units other than the processing unit to which the task was allocated for processing for a first time.

A graphics processing system includes a plurality of processing units, wherein the graphics processing system is configured to process a task first and second times at the plurality of processing units. Data identifying which processing unit of the plurality of processing units the task has been allocated to is consulted on allocating the task to a processing unit for processing for a second time, and, in response, the task is allocated for processing for the second time to any processing unit of the plurality of processing units other than the processing unit to which the task was allocated for processing for a first time.