Abstract: Failure recovery within clustered systems is simulated. For each of a number of failure conditions for an initial state of a number of computing elements of a computerized system, a failure state of the computing elements is generated that corresponds to the failure condition and that is based on the initial state of the computing elements. A failure condition may include one or more hardware and/or software failures. For each failure state of the computing elements, a recovery state is then generated, or simulated, for the computing elements, based on the failure state and the initial state of the computing elements and on a number of recovery rules for the computing elements. Each recovery state is then output for subsequent analysis, where such analysis may be either with human interaction, or automatically and without human interaction.

Abstract: Failure recovery within clustered systems is simulated. For each of a number of failure conditions for an initial state of a number of computing elements of a computerized system, a failure state of the computing elements is generated that corresponds to the failure condition and that is based on the initial state of the computing elements. A failure condition may include one or more hardware and/or software failures. For each failure state of the computing elements, a recovery state is then generated, or simulated, for the computing elements, based on the failure state and the initial state of the computing elements and on a number of recovery rules for the computing elements. Each recovery state is then output for subsequent analysis, where such analysis may be either with human interaction, or automatically and without human interaction.

Abstract: A system and means for identifying references by a process or a subprogram of a process to deallocated memory in a dynamic memory allocation system. The system and method are effective in identifying such references even before they have manifested themselves, and also in identifying the perpetrators of such references. The system and method make use of that portion of the address space of the process which is not otherwise used. A dynamic memory allocation function responds to a requestor's request for memory allocation by mapping memory which the function is allocating to the requestor into otherwise-unused virtual address space, recording this mapping in the system's memory map, and returning the virtual address to the requestor for use in referencing the allocated memory. Hence, any attempted access by the requestor to the allocated memory uses the virtual address, and the virtual address must be translated through the process memory map before the access can be established.