Abstract: A mechanism for replicating programs executing on a computer system having a first storage means is provided. The mechanism identifies the events corresponding to requests from one executing program, which may be different from the executing program to be replicated, which are non-deterministic and identifies the ‘Non Abortable Events’ (NAE's), which change irremediably the state of the external world that need to be reproduced in the replay of the programs. These events are immediately transferred for replay and the executing program is blocked until the transfer is acknowledged. For the other non-deterministic events, they are logged and sent to the executing program, the executing programs remaining blocked only if the log is full and/or if a timer between two NAEs expires, in this case a log transfer to the standby machine is performed to prepare replication before unblocking of the executing program.

Abstract: This invention relates to a transparent and non-intrusive method for monitoring and managing the running of tasks executed in one or more computer processors, in particular in multi-processor systems with a parallel architecture. It proposes a system and method for managing a computer task, termed target, during a given execution period, termed activity period (SchJ, SchR), within a computer system, in a computer processor provided with means of monitoring or estimating performance and including a counter (PMC) with a given possible error in plus or minus, termed relative error, this process comprising on the one hand, an evaluation of a number of executed instructions (NR, NJ) up to at least one given point of said activity period, using said counter; and on the other hand, a generation of data, termed signature (SGJ, SGR), read or calculated from the state of the processor or computer system and corresponding to at least one given point of said activity period.

Abstract: A mechanism for replicating programs executing on a computer system having a first storage means is provided. The mechanism identifies the events corresponding to requests from one executing program, which may be different from the executing program to be replicated, which are non-deterministic and identifies the ‘Non Abortable Events’ (NAE's), which change irremediably the state of the external world that need to be reproduced in the replay of the programs. These events are immediately transferred for replay and the executing program is blocked until the transfer is acknowledged. For the other non-deterministic events, they are logged and sent to the executing program, the executing programs remaining blocked only if the log is full and/or if a timer between two NAEs expires, in this case a log transfer to the standby machine is performed to prepare replication before unblocking of the executing program.

Abstract: This invention relates to a transparent and non-intrusive method for monitoring and managing the running of tasks executed in one or more computer processors, in particular in multi-processor systems with a parallel architecture. It proposes a system and method for managing a computer task, termed target, during a given execution period, termed activity period (SchJ, SchR), within a computer system, in a computer processor provided with means of monitoring or estimating performance and including a counter (PMC) with a given possible error in plus or minus, termed relative error, this process comprising on the one hand, an evaluation of a number of executed instructions (NR, NJ) up to at least one given point of said activity period, using said counter; and on the other hand, a generation of data, termed signature (SGJ, SGR), read or calculated from the state of the processor or computer system and corresponding to at least one given point of said activity period.