基於IaaS雲端平台之CDN服務研究

Abstract

在雲端運算盛行的年代，用多少付多少的概念已取代固定付費租用服務的模式。而 Infrastructure as a Service(IaaS)等服務的興起，更讓網路内容提供者有很大的彈 性隨時增加減少租用資源。現今發展也帶來一種可能方向：同時租用的IaaS服務不止一 家，依使用的需求與成本，彈性地增減使用資源，而且在不同地區選用當地服務品質與 成本之間評比最合適的一家或多家IaaS營運商來組合與建構服務。另一方面，内容傳遞 網路(CDN)已經發展超過十年的時間，它提供網站經營所必須的效率，即快速的回應時間及 穩定的服務，讓網站的資料放置在離使用者最近的地方，且讓伺服器的負擔及延遲時間減 至最少。

本計晝將建置一套基於Hybrid IaaS的應用服務。此服務以串聯不同IaaS之服務為 底層，在其上佈建内容傳遞網路(CDN)為應用層，組成一套可部署於全球的雲端内容傳 遞網路服務。在探討如何最小化所租用的虛擬主機數的同時，又能令使用者感受到的内容 傳遞品質不受影響，並搭配自動化應用程式部署與資源最佳化，使得部署CDN服務的成本降 低。此外，第一階段的CDN應用以靜態内容的加速為主，第二階段的CDN應用將結合分散 式資料庫，使其支援動態内容加速。本研究預期將有助於大企業或組織以Hybrid IaaS 的方式減少外包CDN服務的成本。

In the Cloud Computing age, pay as you use model becomes more acceptable than fix price model while using cloud resources. For example, the technology of Infrastructure as a Service (IaaS) provides a flexible way to increase or decrease resources and charge according to real usage. In the meanwhile, it is possible that combine two or more IaaS service at the same time from different service providers according to cost, service performance and geography location. Besides, content delivery network has been developed over one decade. It guarantees enough efficiency, which means acceptable response time for users. This is achieved by storing web content which near to user’s geography location.

In this proposal, we want to build a hybrid IaaS based application. This application connects different IaaS platform from different service providers and integrates content delivery service together. We hope to minimize the resources used and ensure acceptable service quality for users at the same time. Moreover, how to deploy service automatically between different IaaS platform to reduce operating cost is also an important issue. We will develop a static content based CDN service at first year and then develop dynamic content based CDN service with distributed database in the second year. From outsourcing CDN service to host hybrid IaaS directly, this research would help large organization to reduce business cost.