Azure 如何運作?How does Azure work?

Azure 是 Microsoft 的公用雲端平台。Azure is Microsoft's public cloud platform. Azure 提供一系列大型的服務,包括平臺即服務 (PaaS) 、基礎結構即服務 (IaaS) 和受控資料庫服務功能。Azure offers a large collection of services including platform as a service (PaaS), infrastructure as a service (IaaS), and managed database service capabilities. 但 Azure 到底是什麼?它如何運作?But what exactly is Azure, and how does it work?

Azure 就像其他雲端平台一樣,需仰賴名為 虛擬化 的技術。Azure, like other cloud platforms, relies on a technology known as virtualization. 大部分的電腦硬體都可用軟體來模擬,因為大部分的電腦硬體都只是一組永久或半永久編碼在矽晶片材料中的指令。Most computer hardware can be emulated in software, because most computer hardware is simply a set of instructions permanently or semi-permanently encoded in silicon. 使用將軟體指令對應至硬體指令的模擬層,虛擬化的硬體即可用軟體執行,如同在實際的硬體中執行一般。Using an emulation layer that maps software instructions to hardware instructions, virtualized hardware can execute in software as if it were the actual hardware itself.

基本上,雲端是一或多個資料中心內部代替客戶執行虛擬化硬體的一組實體伺服器。Essentially, the cloud is a set of physical servers in one or more datacenters that execute virtualized hardware on behalf of customers. 那麼,雲端要如何同時為數百萬個客戶建立、啟動、停止及刪除數百萬個虛擬化硬體執行個體呢?So how does the cloud create, start, stop, and delete millions of instances of virtualized hardware for millions of customers simultaneously?

要了解這一點,就必須看看資料中心裡的硬體架構。To understand this, let's look at the architecture of the hardware in the datacenter. 在每個資料中心內都是位於伺服器機架中的伺服器集合。Inside each datacenter is a collection of servers sitting in server racks. 每個伺服器機架都包含許多伺服器 刀鋒,以及提供網路連線的網路交換器和提供電力的配電裝置 (PDU)。Each server rack contains many server blades as well as a network switch providing network connectivity and a power distribution unit (PDU) providing power. 機架有時會一起分組到較大的單位中,名為 叢集Racks are sometimes grouped together in larger units known as clusters.

在每個機架或叢集內,大部分的伺服器都會被指定用來代替使用者執行這些虛擬化硬體執行個體。Within each rack or cluster, most of the servers are designated to run these virtualized hardware instances on behalf of the user. 但是有些伺服器會執行稱為網狀架構控制器的雲端管理軟體。But some of the servers run cloud management software known as a fabric controller. 網狀架構控制器 是一種分散式應用程式,負責執行多項工作。The fabric controller is a distributed application with many responsibilities. 它會配置服務、監視伺服器及其執行之服務的健全狀況,並在伺服器故障時加以修復。It allocates services, monitors the health of the server and the services running on it, and heals servers when they fail.

每個網狀架構控制器執行個體都會連線至執行雲端協調流程軟體的另一組伺服器,一般稱之為 前端Each instance of the fabric controller is connected to another set of servers running cloud orchestration software, typically known as a front end. 前端會主控 Web 服務、RESTful API,以及雲端執行的所有功能所使用的內部 Azure 資料庫。The front end hosts the web services, RESTful APIs, and internal Azure databases used for all functions the cloud performs.

例如,前端會裝載處理客戶要求的服務,以配置 Azure 資源(例如 虛擬機器)和服務(例如 azure Cosmos DB)。For example, the front end hosts the services that handle customer requests to allocate Azure resources such as virtual machines, and services like Azure Cosmos DB. 首先,前端會驗證使用者,並確認使用者是否有權配置要求的資源。First, the front end validates the user and verifies the user is authorized to allocate the requested resources. 如果是,前端會檢查資料庫以找出具有足夠容量的伺服器機架,然後指示該機架上的網狀架構控制器配置資源。If so, the front end checks a database to locate a server rack with sufficient capacity and then instructs the fabric controller on that rack to allocate the resource.

基本上,Azure 是一組龐大的伺服器和網路硬體,執行一組複雜的分散式應用程式,以協調這些伺服器上虛擬化硬體和軟體的設定和操作。So fundamentally, Azure is a huge collection of servers and networking hardware running a complex set of distributed applications to orchestrate the configuration and operation of the virtualized hardware and software on those servers. 這是讓 Azure 變得強大的協調流程,因為因為 Azure 會在幕後完成這些工作,所以使用者不再負責維護和升級硬體。It is this orchestration that makes Azure so powerful, because users are no longer responsible for maintaining and upgrading hardware because Azure does all this behind the scenes.

下一步Next steps

透過適用于 Azure 的 Microsoft 雲端採用架構,深入瞭解雲端採用。Learn more about cloud adoption with the Microsoft Cloud Adoption Framework for Azure.