Name: 亞馬遜網絡服務教程 - 自動擴展應用程序 (Amazon Web Services Tutorial - Auto scaling your applications)
Uploaded: 2025-08-06T18:38:16.000Z
Duration: 7 min 59 s

EC2 stands for Elastic Compute Cloud and the word of the day is elastic.

EC2 是 Elastic Compute Cloud（彈性計算雲）的縮寫，今天的關鍵詞是 elastic。

An auto-scaling policy can tell AWS that when an event occurs, such as our instance CPU usage goes above 80% for five minutes, to stretch our one server into two.

自動擴展策略可以告訴 AWS，當發生事件時，比如我們的實例 CPU 使用率在五分鐘內超過 80%，就將我們的一臺服務器擴展為兩臺。

And then we can tell it to shrink back down again to one server when things have calmed down again.

當一切恢復平靜後，我們可以告訴它重新縮回到一臺服務器。

Your application needs to be designed in a way that if one or two or ten clones of your single server come online, that your application can load balance your traffic across all these new servers.

您的應用程序在設計時需要考慮到，如果有一臺、兩臺或十臺克隆服務器上線，您的應用程序可以在所有這些新服務器之間平衡流量負載。

If you think of a busy grocery store, the manager will open several new checkout lanes to reduce wait time.

如果你想到一家繁忙的雜貨店，店長會開設幾條新的收銀通道以減少等待時間。

When the rush is over, they'll close those extra checkout lanes.

當高峰期結束後，他們會關閉多餘的結賬通道。

This is different than vertical scaling, which would handle the problem by still only having a single checkout lane, but just putting a faster cashier and speeding up the conveyor belt.

這與垂直擴展不同，後者處理問題的方式仍然是隻有一條收銀通道，只是增加一個速度更快的收銀員，並加快傳送帶的速度。

在 AWS 中，縱向擴展相當容易。

You just stop your running EC2 instance, which will cause a little downtime, and change the instance to a larger, faster server with more CPU cores and RAM.

您只需停止正在運行的 EC2 實例（這將導致少許停機），然後將實例更改為更大、更快、CPU 內核和內存更多的服務器。

But this has its limits, and all large applications use horizontal scaling to handle an increase in traffic.

但這有其侷限性，所有大型應用程序都使用水準擴展來處理流量的增加。

We're not going to set up autoscaling for this course, but we will create an AMI snapshot of our current running server and create a clone of it manually, which is one of the first steps to setting up autoscaling anyway.

在本課程中，我們不會設置自動擴展，但我們將創建當前運行服務器的 AMI 快照，並手動創建其克隆，無論如何，這是設置自動擴展的第一步。

If you'd like to dive deeper into autoscaling, I recommend our AWS course on automation and optimization.

如果您想深入瞭解自動擴展，我向您推薦我們的 AWS 自動化和優化課程。

Okay, if you're totally new to these concepts of horizontally scaling servers in your application design, search our catalog for AWS high availability, and we have a few courses that'll show you how to keep your application running when a single server fails, or when that single server gets overloaded due to high demand.

好的，如果你對在應用程序設計中橫向擴展服務器的概念完全陌生，請在我們的目錄中搜索 AWS 高可用性，我們有一些課程會告訴你如何在單個服務器出現故障或單個服務器因需求過高而超載時保持應用程序的運行。

Finish out this course first, though, because you're going to need to know a bit more about storage and networking in AWS to get a full understanding of the material that's presented in those courses.

不過，您需要先學完這門課程，因為您需要對 AWS 中的存儲和網絡有更多瞭解，才能充分理解這些課程中介紹的材料。

So, let's jump into the console, and I'll show you how to clone our existing server.

那麼，讓我們跳轉到控制檯，我將向你展示如何克隆現有的服務器。

In the EC2 console, on the left, click on Instances, and select your running instance.

在 EC2 控制檯左側，單擊 "實例"，然後選擇正在運行的實例。

Then, click on the Actions pulldown above it and take a look at a few of these options.

然後，點擊上方的 "操作 "下拉菜單，查看其中的幾個選項。

Under the Instance State pulldown, you can stop and start the instance, and you'll also see a reboot option.

在 "實例狀態 "下拉菜單中，可以停止和啟動實例，還可以看到重啟選項。

Now, if you stop an instance, you won't be charged for the compute time while the instance is stopped, but you will be charged for the storage costs of its hard drive, which are pretty minimal.

現在，如果你停止一個實例，你將不會被收取實例停止時的計算時間費用，但你將被收取其硬盤驅動器的存儲費用，而這些費用是相當低的。

You can click to start and bring the instance back up again.

您可以點擊 "啟動"，重新啟動實例。

If you click Reboot, it'll force a software reboot of the virtual machine.

如果單擊 "重啟"，將強制軟件重啟虛擬機。

If you stop and start an instance, this virtual machine will actually move to another physical server in the availability zone.

如果您停止並啟動一個實例，該虛擬機實際上會移動到可用區中的另一臺物理服務器上。

So, do this if you're having problems connecting to the instance, because it could be a hardware failure on the AWS side.

是以，如果您在連接實例時遇到問題，請執行此操作，因為這可能是 AWS 方面的硬件故障。

Back in the Detail pane, click on the Status Checks tab.

回到 "詳細信息 "窗格，單擊 "狀態檢查 "選項卡。

You'll notice the system status check is failing if there's a hardware failure, but it takes a few minutes for AWS to see the problem, so you might notice the problem before the alarm goes off.

如果出現硬件故障，你會發現系統狀態檢查失效，但 AWS 需要幾分鐘才能看到問題，是以你可能會在警報響起前發現問題。

If you reboot an instance, it'll come up faster, but it stays on the same physical server it was on before.

如果重新啟動實例，啟動速度會更快，但仍會保留在原來的物理服務器上。

Okay, click on Actions again, and select Image, and then select Create Image.

好的，再次點擊 "操作"，選擇 "影像"，然後選擇 "創建影像"。

And you'll see an option here that says No Reboot.

然後你會看到一個選項，上面寫著 "不重啟"。

AWS needs to reboot the virtual machine to take a proper image of it, so this properly shuts down the file system and lets AWS take a clean image of the virtual machine, but it does cause a little bit of downtime.

AWS 需要重啟虛擬機以獲取適當的映像，是以這可以正確關閉文件系統，讓 AWS 獲取虛擬機的乾淨映像，但這確實會導致一點停機時間。

If you select No Reboot, well, good luck to you.

如果您選擇 "不重啟"，那麼祝您好運。

Click the Create Image button, and then click Close.

單擊創建影像按鈕，然後單擊關閉。

On the left-hand submenu, click on AMIs underneath the image header.

在左側子菜單中，點擊影像標題下方的 AMI。

You'll see a spinner next to our AMI, while AWS reboots the instance and takes a snapshot of it.

你會看到我們的 AMI 旁邊有一個旋轉器，同時 AWS 會重啟實例並對其進行快照。

When the AMI image says that it's available, click on it, and click on the Launch button.

當 AMI 映像顯示可用時，點擊它，然後點擊 "啟動 "按鈕。

Now we're back on the EC2 launch screen, but we're launching a new server based on our server image.

現在，我們又回到了 EC2 啟動界面，但我們正在根據服務器鏡像啟動一個新服務器。

Select T2 Micro again, and then click the Next Configure Instance Details button.

再次選擇 T2 Micro，然後單擊 "下一步配置實例詳細信息 "按鈕。

Under Subnet, select an availability zone that's different from the other instance.

在子網下，選擇與其他實例不同的可用性區域。

So my other instance was in US East 1A, so now I'm going to pick US East 1B.

我的另一個例子是在美東 1A，所以現在我要選美東 1B。

Click Next, and then click Next again, and then click Next one final time to configure the security group.

單擊 "下一步"，然後再次單擊 "下一步"，最後單擊 "下一步 "配置安全組。

Under Assign Security Group, I want to select an existing security group, and I'm going to select Launch Wizard 2, because that's the security group that my other instance is using.

在 "指定安全組 "下，我要選擇一個現有的安全組，並選擇 "啟動向導 2"，因為我的另一個實例使用的就是這個安全組。

You'll notice in the rules that HTTP is now open to the entire Internet.

您會注意到，在規則中，HTTP 現在向整個互聯網開放。

Click Review and Launch, and click Launch.

單擊 "審查和啟動"，然後單擊 "啟動"。

This time, I'm going to choose an existing key pair, and I'm going to make sure that I'm selecting my AWS demo key pair that I used for my other instance.

這一次，我將選擇一個現有的密鑰對，並確保選擇我在其他實例中使用的 AWS 演示密鑰對。

Select the Acknowledge checkbox, and click Launch Instances.

選擇 "確認 "複選框，然後單擊 "啟動實例"。

You'll see that our other instance is now spinning up.

你會看到我們的另一個實例正在啟動。

This instance is in availability zone 1B, whereas my original instance is in availability zone 1A.

該實例位於可用性區域 1B，而我原來的實例位於可用性區域 1A。

And I'm also going to edit the name and call this Web Server 2.

我還要編輯名稱，將其命名為網絡服務器 2。

Click on the new instance, and click on the Description tab, and then copy its public DNS.

單擊新實例，單擊 "描述 "選項卡，然後複製其公共 DNS。

In a new browser tab, type http:// and paste in the DNS name.

在新的瀏覽器標籤頁中，輸入 http:// 並粘貼 DNS 名稱。

You'll see the default Apache site again, because remember, this server is a clone of the server that we just set up.

你將再次看到默認的 Apache 網站，因為請記住，這臺服務器是我們剛剛建立的服務器的克隆。

An AMI image is a great way to take a snapshot in time of your server in its full configuration, and then launch new instances to, say, handle a spike in traffic or restore the instance to a previous state if it gets messed up somehow.

AMI 映像是一種很好的方法，它能及時獲取服務器完整配置的快照，然後啟動新實例來處理流量激增，或者在實例出現故障時將其恢復到以前的狀態。

Let's leave both instances running, but remember to come back after you're done and click on Actions, Instance State, Terminate, and delete both instances so that you're not running up your bill.

讓兩個實例都繼續運行，但完成後記得回來點擊 "操作"、"實例狀態"、"終止"，刪除兩個實例，這樣就不會增加你的賬單了。