Method and system for frequent checkpointing

摘要

A virtualization platform provides fault tolerance for a primary virtual machine by continuously transmitting checkpoint information of the primary virtual machine to a collector process, such as a backup virtual machine. When implemented on a hardware platform comprising a multi-processor that supports nested page tables, the virtualization platform leverages the nested page table support to quickly identify memory pages that have been modified between checkpoints. The backup virtual machine provides feedback information to assist the virtualization platform in identifying candidate memory pages for transmitting actual modifications to the memory pages rather than the entire memory page as part of the checkpoint information. The virtualization platform further maintains a modification history data structure to identify memory pages that can be transmitted simultaneous with the execution of the primary virtual machine rather than while the primary virtual machine has been stunned.

主权项

1. A method of transmitting modifications made to a memory page of a running virtual machine during an incremental checkpoint time interval, the method comprising:
stunning the running virtual machine at the end of the incremental checkpoint time interval; while the virtual machine is stunned, computing a difference value for the memory page, the difference value quantifying changes made to the memory page during the incremental checkpoint time interval; and transmitting either the changes to the memory page or the entire memory page based on the difference value.