Amazon EC2 Spot 執行個體教學課程

您可以批次處理任務，需要花費數小時或數天的時間完成。但是，在開始和結束時都有彈性。您想要查看是否能以低於隨需執行個體的成本將它完成。

您可以使用 Amazon EC2 主控台或 Amazon EC2 來檢查 Spot Price 歷史記錄的執行個體類型API。於一個給定的可用區域內分析您所想要的執行個體類型的歷史價格後，您的出價有兩個替代方式：

您有一個要執行的資料正在處理任務。您充分了解任務結果的值，以得知其在運算成本方面的價值。

分析執行個體類型的 Spot 價格歷史記錄後，您可以選擇運算時間成本不超過任務結果值的價格。您建立可以長久出價的方式，且允許它在 Spot 價格出現波動並等於或低於您的出價時，間歇性地執行。

對於無法透過隨需執行個體取得的額外容量，您有非預期的短期需求。分析執行個體類型的 Spot 價格歷史記錄後，您可以選擇高於最高歷史價格的價格，以大幅提高快速滿足請求的可能性，並繼續運算，直到完成為止。

NuGet 套件：

程式設計元素：

using System;
using System.Threading;
using System.Threading.Tasks;
using System.Collections.Generic;
using Amazon.EC2;
using Amazon.EC2.Model;

namespace EC2SpotInstanceRequests
{
  class Program
  {
    static async Task Main(string[] args)
    {
      // Some default values.
      // These could be made into command-line arguments instead.
      var instanceType = InstanceType.T1Micro;
      string securityGroupName = "default";
      string spotPrice = "0.003";
      int instanceCount = 1;

      // Parse the command line arguments
      if((args.Length != 1) || (!args[0].StartsWith("ami-")))
      {
        Console.WriteLine("\nUsage: EC2SpotInstanceRequests ami");
        Console.WriteLine("  ami: the Amazon Machine Image to use for the Spot Instances.");
        return;
      }

      // Create the Amazon EC2 client.
      var ec2Client = new AmazonEC2Client();

      // Create the Spot Instance request and record its ID
      Console.WriteLine("\nCreating spot instance request...");
      var req = await CreateSpotInstanceRequest(
        ec2Client, args[0], securityGroupName, instanceType, spotPrice, instanceCount);
      string requestId = req.SpotInstanceRequestId;

      // Wait for an EC2 Spot Instance to become active
      Console.WriteLine(
        $"Waiting for Spot Instance request with ID {requestId} to become active...");
      int wait = 1;
      var start = DateTime.Now;
      while(true)
      {
        Console.Write(".");

        // Get and check the status to see if the request has been fulfilled.
        var requestInfo = await GetSpotInstanceRequestInfo(ec2Client, requestId);
        if(requestInfo.Status.Code == "fulfilled")
        {
          Console.WriteLine($"\nSpot Instance request {requestId} " +
            $"has been fulfilled by instance {requestInfo.InstanceId}.\n");
          break;
        }

        // Wait a bit and try again, longer each time (1, 2, 4, ...)
        Thread.Sleep(wait);
        wait = wait * 2;
      }

      // Show the user how long it took to fulfill the Spot Instance request.
      TimeSpan span = DateTime.Now.Subtract(start);
      Console.WriteLine($"That took {span.TotalMilliseconds} milliseconds");

      // Perform actions here as needed.
      // For this example, simply wait for the user to hit a key.
      // That gives them a chance to look at the EC2 console to see
      // the running instance if they want to.
      Console.WriteLine("Press any key to start the cleanup...");
      Console.ReadKey(true);

      // Cancel the request.
      // Do this first to make sure that the request can't be re-fulfilled
      // once the Spot Instance has been terminated.
      Console.WriteLine("Canceling Spot Instance request...");
      await CancelSpotInstanceRequest(ec2Client, requestId);

      // Terminate the Spot Instance that's running.
      Console.WriteLine("Terminating the running Spot Instance...");
      await TerminateSpotInstance(ec2Client, requestId);

      Console.WriteLine("Done. Press any key to exit...");
      Console.ReadKey(true);
    }


    //
    // Method to create a Spot Instance request
    private static async Task<SpotInstanceRequest> CreateSpotInstanceRequest(
      IAmazonEC2 ec2Client, string amiId, string securityGroupName,
      InstanceType instanceType, string spotPrice, int instanceCount)
    {
      var launchSpecification = new LaunchSpecification{
        ImageId = amiId,
        InstanceType = instanceType
      };
      launchSpecification.SecurityGroups.Add(securityGroupName);
      var request = new RequestSpotInstancesRequest{
        SpotPrice = spotPrice,
        InstanceCount = instanceCount,
        LaunchSpecification = launchSpecification
      };

      RequestSpotInstancesResponse result =
        await ec2Client.RequestSpotInstancesAsync(request);
      return result.SpotInstanceRequests[0];
    }


    //
    // Method to get information about a Spot Instance request, including the status,
    // instance ID, etc.
    // It gets the information for a specific request (as opposed to all requests).
    private static async Task<SpotInstanceRequest> GetSpotInstanceRequestInfo(
      IAmazonEC2 ec2Client, string requestId)
    {
      var describeRequest = new DescribeSpotInstanceRequestsRequest();
      describeRequest.SpotInstanceRequestIds.Add(requestId);

      DescribeSpotInstanceRequestsResponse describeResponse =
        await ec2Client.DescribeSpotInstanceRequestsAsync(describeRequest);
      return describeResponse.SpotInstanceRequests[0];
    }


    //
    // Method to cancel a Spot Instance request
    private static async Task CancelSpotInstanceRequest(
      IAmazonEC2 ec2Client, string requestId)
    {
      var cancelRequest = new CancelSpotInstanceRequestsRequest();
      cancelRequest.SpotInstanceRequestIds.Add(requestId);

      await ec2Client.CancelSpotInstanceRequestsAsync(cancelRequest);
    }


    //
    // Method to terminate a Spot Instance
    private static async Task TerminateSpotInstance(
      IAmazonEC2 ec2Client, string requestId)
    {
      var describeRequest = new DescribeSpotInstanceRequestsRequest();
      describeRequest.SpotInstanceRequestIds.Add(requestId);

      // Retrieve the Spot Instance request to check for running instances.
      DescribeSpotInstanceRequestsResponse describeResponse =
        await ec2Client.DescribeSpotInstanceRequestsAsync(describeRequest);

      // If there are any running instances, terminate them
      if(   (describeResponse.SpotInstanceRequests[0].Status.Code
              == "request-canceled-and-instance-running")
         || (describeResponse.SpotInstanceRequests[0].State == SpotInstanceState.Active))
      {
        TerminateInstancesResponse response =
          await ec2Client.TerminateInstancesAsync(new TerminateInstancesRequest{
            InstanceIds = new List<string>(){
              describeResponse.SpotInstanceRequests[0].InstanceId } });
        foreach (InstanceStateChange item in response.TerminatingInstances)
        {
          Console.WriteLine($"\n  Terminated instance: {item.InstanceId}");
          Console.WriteLine($"  Instance state: {item.CurrentState.Name}\n");
        }
      }
    }
  }
}