虛擬機器支援無資料遺失之網際網路服務系統

Abstract

近年來網際網路服務越來越盛行，越來越多企業使用網際網路系統提供商業性的服務。根據研究顯示，如果商業性的網際網路系統無法提供服務，將會造成企業重大的損失。然而，有許多因素會使得網際網路系統無法提供服務，這因素包括系統出錯及系統維護。 因此，我們提出一個無資料遺失的網際網路服務系統，使得網際網路服務能夠永續運作。他能夠自動發現系統錯誤，並且在使用者沒有察覺的情況下，回復所有在錯誤發生時正在服務的請求。並且我們也提供一套方法，能使得網際網路服務系統能在不用關閉服務的情況下做系統維護。我們將在虛擬機器-Xen,及虛擬機器上的作業系統上實作我們的架構。根據實驗結果，這個系統在正常情況只需要花費少量的時間來記錄連線狀態。錯誤回復的速度也在可以接受的範圍。

In recent years, Internet services have become more and more popular in our daily life. More and more commercial services are provided through Internet. According to previous research, a few minutes of downtime of a commercial Internet service will lead to a great loss of money for the company. Furthermore, system failures and system maintenance contribute to most of the service unavailability. In order to keep Internet service running permanently, we provide a framework based on virtual machines to allow zero-loss service recovery and upgrade. The framework can detect system faults automatically and transparently recover the on-line requests. Moreover, it also allows on-line requests to be migrated to an upgraded system. We implemented the framework by modifying an open source virtual machine monitor, Xen, and the Linux kernel on top of Xen. According to the experimental results, the framework causes little overhead and has acceptable recovery time.