Abstract: Dynamic program analysis is decoupled from execution in virtual computer environments so that program analysis can be performed on a running computer program without affecting or perturbing the workload of the system on which the program is executing. Decoupled dynamic program analysis is enabled by separating execution and analysis into two tasks: (1) recording, where system execution is recorded with minimal interference, and (2) analysis, where the execution is replayed and analyzed.

Abstract: The method of taking checkpoints of a virtual computing instance running in a first host computer at varying time intervals includes queuing outgoing network data packets of the virtual computing instance during execution of the virtual computing instance, triggering a process to take the checkpoint, the process including generating a checkpoint information packet and transmitting the checkpoint information packet to a second host computer, and upon receiving acknowledgement from the second host computer of receipt of the checkpoint information packet, releasing the outgoing network data packets of the virtual computing instance that have been queued and not released. The triggering time for the process to take the checkpoint is dependent on characteristics of workload executed by the virtual computing instance.

Abstract: During checkpointing of a virtual computing instance running in a first host computer, memory pages that have been modified during a checkpoint time interval are lazily transmitted from the first host computer to a second, backup, host computer. The lazy transmission technique includes the steps of stunning the virtual computing instance at the end of the time interval, and after said stunning, (i) detecting at the first host computer the memory pages that have been modified during the time interval, and (ii) copying one or more of the modified memory pages to a memory region in the first host computer. Then, after the virtual computing instance resumes execution, i.e., while the virtual computing instance is running in the first host computer, the copied memory pages are transmitted from the memory region in the first host computer to the second host computer.

Abstract: Dynamic program analysis is decoupled from execution in virtual computer environments so that program analysis can be performed on a running computer program without affecting or perturbing the workload of the system on which the program is executing. Decoupled dynamic program analysis is enabled by separating execution and analysis into two tasks: (1) recording, where system execution is recorded with minimal interference, and (2) analysis, where the execution is replayed and analyzed.

Abstract: The method of taking checkpoints of a virtual computing instance running in a first host computer at varying time intervals includes queuing outgoing network data packets of the virtual computing instance during execution of the virtual computing instance, triggering a process to take the checkpoint, the process including generating a checkpoint information packet and transmitting the checkpoint information packet to a second host computer, and upon receiving acknowledgement from the second host computer of receipt of the checkpoint information packet, releasing the outgoing network data packets of the virtual computing instance that have been queued and not released. The triggering time for the process to take the checkpoint is dependent on characteristics of workload executed by the virtual computing instance.

Abstract: During checkpointing of a virtual computing instance running in a first host computer, memory pages that have been modified during a checkpoint time interval are lazily transmitted from the first host computer to a second, backup, host computer. The lazy transmission technique includes the steps of stunning the virtual computing instance at the end of the time interval, and after said stunning, (i) detecting at the first host computer the memory pages that have been modified during the time interval, and (ii) copying one or more of the modified memory pages to a memory region in the first host computer. Then, after the virtual computing instance resumes execution, i.e., while the virtual computing instance is running in the first host computer, the copied memory pages are transmitted from the memory region in the first host computer to the second host computer.