# .NET and DAX
<a name="DAX.client.run-application-dotnet"></a>

Follow these steps to run the .NET sample on your Amazon EC2 instance.

**Note**  
This tutorial uses the .NET 9 SDK. It shows how you can run a program in your default Amazon VPC to access your Amazon DynamoDB Accelerator (DAX) cluster. It works with the [AWS SDK v4 for .NET ](https://docs.aws.amazon.com/sdk-for-net/v4/developer-guide/welcome.html). For details about changes in V4 and information about migrating, see [Migrating to version 4 of the AWS SDK for .NET](https://docs.aws.amazon.com/sdk-for-net/v4/developer-guide/net-dg-v4.html). If you prefer, you can use the AWS Toolkit for Visual Studio to write a .NET application and deploy it into your VPC.  
For more information, see [Creating and Deploying Elastic Beanstalk Applications in .NET Using AWS Toolkit for Visual Studio](https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/create_deploy_NET.html) in the *AWS Elastic Beanstalk Developer Guide*.

**To run the .NET sample for DAX**

1. Go to the [Microsoft Downloads page](https://www.microsoft.com/net/download?initial-os=linux) and download the latest .NET 9 SDK for Linux. The downloaded file is `dotnet-sdk-N.N.N-linux-x64.tar.gz`.

1. Extract the SDK files.

   ```
   mkdir dotnet
   tar zxvf dotnet-sdk-N.N.N-linux-x64.tar.gz -C dotnet
   ```

   Replace `N.N.N` with the actual version number of the .NET SDK (for example: `9.0.305`).

1. Verify the installation.

   ```
   alias dotnet=$HOME/dotnet/dotnet
   dotnet --version
   ```

   This should print the version number of the .NET SDK.
**Note**  
Instead of the version number, you might receive the following error:  
error: libunwind.so.8: cannot open shared object file: No such file or directory  
To resolve the error, install the `libunwind` package.  

   ```
   sudo yum install -y libunwind
   ```
After you do this, you should be able to run the `dotnet --version` command without any errors.

1. Create a new .NET project.

   ```
   dotnet new console -o myApp 
   ```

   This requires a few minutes to perform a one-time-only setup. When it is complete, run the sample project.

   ```
   dotnet run --project myApp
   ```

   You should receive the following message: `Hello World!`

1. The `myApp/myApp.csproj` file contains metadata about your project. To use the DAX client in your application, modify the file so that it looks like the following.

   ```
   <Project Sdk="Microsoft.NET.Sdk">
       <PropertyGroup>
           <OutputType>Exe</OutputType>
           <TargetFramework>net9.0</TargetFramework>
       </PropertyGroup>
       <ItemGroup>
           <PackageReference Include="AWSSDK.DAX.Client" Version="*" />
       </ItemGroup>
   </Project>
   ```

1. Download the sample program source code (`.zip` file).

   ```
   wget http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/samples/TryDax.zip
   ```

   When the download is complete, extract the source files.

   ```
   unzip TryDax.zip
   ```

1. Now run the sample programs of *dotNet*, one at a time. For each program, copy its contents into the `myApp/Program.cs`, and then run the `MyApp` project.

   Run the following .NET programs. The first program creates a DynamoDB table named `TryDaxTable`. The second program writes data to the table.

   ```
   cp TryDax/dotNet/01-CreateTable.cs myApp/Program.cs
   dotnet run --project myApp
   
   cp TryDax/dotNet/02-Write-Data.cs myApp/Program.cs
   dotnet run --project myApp
   ```

1. Next, run some programs to perform `GetItem`, `Query`, and `Scan` operations on your DAX cluster. To determine the endpoint for your DAX cluster, choose one of the following:
   +  **Using the DynamoDB console** — Choose your DAX cluster. The cluster endpoint is shown on the console, as in the following example.

     ```
     dax://my-cluster.l6fzcv.dax-clusters.us-east-1.amazonaws.com
     ```
   + **Using the AWS CLI** — Enter the following command.

     ```
     aws dax describe-clusters --query "Clusters[*].ClusterDiscoveryEndpoint"
     ```

     The cluster endpoint is shown in the output, as in the following example.

     ```
     {
         "Address": "my-cluster.l6fzcv.dax-clusters.us-east-1.amazonaws.com",
         "Port": 8111,
         "URL": "dax://my-cluster.l6fzcv.dax-clusters.us-east-1.amazonaws.com"
     }
     ```

   Now run the following programs, specifying your cluster endpoint as a command line parameter. (Replace the sample endpoint with your actual DAX cluster endpoint.)

   ```
   cp TryDax/dotNet/03-GetItem-Test.cs myApp/Program.cs
   dotnet run --project myApp dax://my-cluster.l6fzcv.dax-clusters.us-east-1.amazonaws.com
   
   cp TryDax/dotNet/04-Query-Test.cs myApp/Program.cs
   dotnet run --project myApp dax://my-cluster.l6fzcv.dax-clusters.us-east-1.amazonaws.com
                           
   cp TryDax/dotNet/05-Scan-Test.cs myApp/Program.cs
   dotnet run --project myApp dax://my-cluster.l6fzcv.dax-clusters.us-east-1.amazonaws.com
   ```

   Take note of the timing information—the number of milliseconds required for the `GetItem`, `Query`, and `Scan` tests.

1. Run the following .NET program to delete `TryDaxTable`.

   ```
   cp TryDax/dotNet/06-DeleteTable.cs myApp/Program.cs
   dotnet run --project myApp
   ```

For more information about these programs, see the following sections:
+ [01-CreateTable.cs](DAX.client.run-application-dotnet.01-CreateTable.md)
+ [02-Write-Data.cs](DAX.client.run-application-dotnet.02-Write-Data.md)
+ [03-GetItem-Test.cs](DAX.client.run-application-dotnet.03-GetItem-Test.md)
+ [04-Query-Test.cs](DAX.client.run-application-dotnet.04-Query-Test.md)
+ [05-Scan-Test.cs](DAX.client.run-application-dotnet.05-Scan-Test.md)
+ [06-DeleteTable.cs](DAX.client.run-application-dotnet.06-DeleteTable.md)