Abstract: A transparent high-availability solution utilizing virtualization technology is presented. A cluster environment and management thereof is implemented through an automated installation and setup procedure resulting in a cluster acting as a single system. The cluster is setup in an isolated virtual machine on each of a number of physical nodes of the system. Customer applications are run within separate application virtual machines on one physical node at a time and are run independently and unaware of their configuration as part of a high-availability cluster. Upon detection of a failure, traffic is rerouted through a redundant node and the application virtual machines are migrated from the failing node to another node using live migration techniques.

Abstract: A transparent high-availability solution utilizing virtualization technology is presented. A cluster environment and management thereof is implemented through an automated installation and setup procedure resulting in a cluster acting as a single system. The cluster is setup in an isolated virtual machine on each of a number of physical nodes of the system. Customer applications are run within separate application virtual machines on one physical node at a time and are run independently and unaware of their configuration as part of a high-availability cluster. Upon detection of a failure, traffic is rerouted through a redundant node and the application virtual machines are migrated from the failing node to another node using live migration techniques.

Abstract: A system is provided for rapidly synchronizing two or more processing elements in a fault-tolerant computing system. Embodiments of this system allow for the rapid synchronization of two processing elements through partial copies of the contents of memory associate with each processing element.

Abstract: A system is provided for rapidly synchronizing two or more processing elements in a fault-tolerant computing system. Embodiments of this system allow for the rapid synchronization of two processing elements through partial copies of the contents of memory associate with each processing element.

Abstract: A system is provided for rapidly synchronizing two or more processing elements in a fault-tolerant computing system. Embodiments of this system allow for the rapid synchronization of two processing elements through partial copies of the contents of memory associate with each processing element.

Abstract: An improved method and apparatus is provided for checkpointing and rollback of network operations. In one embodiment the method includes varying the checkpoint interval in response to a packet deferred timer and buffering data packets that would affect the states of other network devices in a deferred packets queue. The method further generates an outbound packet for transmission to a remote system, buffers the outbound packet until one of a checkpoint or rollback condition is met and varies a checkpoint interval in response to network load. In another embodiment the apparatus includes a transmitter to send an outgoing packet to a remote system, a deferred transmit queue connected to the transmitter and a deferred packet timer that is configured to vary a checkpoint interval based on a predetermined value.

Abstract: The invention relates to checkpointing a disk and/or memory. In one aspect, a first computing device receives a write request that includes a data payload. The first computing device then transmits a copy of the received write request to a second computing device and writes the data payload to a disk. The copy of the write request is queued at a queue on the second computing device until the next checkpoint is initiated or a fault is detected at the first computing device. In another aspect, a processor directs a write request to a location within a first memory. The write request includes at least a data payload and an address identifying the location. An inspection module identifies the write request before it reaches the first memory, copies at least the address identifying the location, and forwards the write request to a memory agent within the first memory.

Abstract: A highly-available computer system is provided. The system includes at least two computer subsystems, each including memory, a local storage device and an embedded operating system. The system also includes a communication link between the two subsystems. Upon the initialization of the two computer subsystems, the embedded operating systems communicate via the communications link and designate one of the two subsystems as dominant. The dominant subsystem then loads a primary operating system. As write operations are sent to the local storage device of the dominant system, the write operations are mirrored over the communications link to each subservient system's local storage device. In the event of a failure of the dominant system, a subservient system will automatically become dominant and continue providing services to end-users.