Support .NET Core 3.1

README.md

@@ -83,8 +83,8 @@ Building from source is very easy and the whole process (from cloning to being a
 
 | |  | Instructions |
 | :---: | :---         |      :--- |
-| ![Windows icon](docs/img/windows-icon-32.png) | **Windows**    | <ul><li>Local - [.NET Framework 4.6.1](docs/building/windows-instructions.md#using-visual-studio-for-net-framework-461)</li><li>Local - [.NET Core 2.1.x](docs/building/windows-instructions.md#using-net-core-cli-for-net-core-21x)</li><ul>    |
-| ![Ubuntu icon](docs/img/ubuntu-icon-32.png) | **Ubuntu**     | <ul><li>Local - [.NET Core 2.1.x](docs/building/ubuntu-instructions.md)</li><li>[Azure HDInsight Spark - .NET Core 2.1.x](deployment/README.md)</li></ul>      |
+| ![Windows icon](docs/img/windows-icon-32.png) | **Windows**    | <ul><li>Local - [.NET Framework 4.6.1](docs/building/windows-instructions.md#using-visual-studio-for-net-framework-461)</li><li>Local - [.NET Core 3.1](docs/building/windows-instructions.md#using-net-core-cli-for-net-core)</li><ul>    |
+| ![Ubuntu icon](docs/img/ubuntu-icon-32.png) | **Ubuntu**     | <ul><li>Local - [.NET Core 3.1](docs/building/ubuntu-instructions.md)</li><li>[Azure HDInsight Spark - .NET Core 3.1](deployment/README.md)</li></ul>      |
 
 <a name="samples"></a>
 ## Samples

azure-pipelines.yml

@@ -24,6 +24,8 @@ jobs:
   variables:
     ${{ if and(ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
       _OfficialBuildIdArgs: /p:OfficialBuildId=$(BUILD.BUILDNUMBER)
+    HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
+    DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp3.1\win-x64
 
   steps:
   - task: Maven@3
@@ -65,8 +67,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.3.0-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - task: DotNetCoreCLI@2
     displayName: 'E2E tests for Spark 2.3.1'
@@ -76,8 +76,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.3.1-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - task: DotNetCoreCLI@2
     displayName: 'E2E tests for Spark 2.3.2'
@@ -87,8 +85,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.3.2-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - task: DotNetCoreCLI@2
     displayName: 'E2E tests for Spark 2.3.3'
@@ -98,8 +94,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.3.3-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - task: DotNetCoreCLI@2
     displayName: 'E2E tests for Spark 2.3.4'
@@ -109,8 +103,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.3.4-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - task: DotNetCoreCLI@2
     displayName: 'E2E tests for Spark 2.4.0'
@@ -120,8 +112,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.4.0-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - task: DotNetCoreCLI@2
     displayName: 'E2E tests for Spark 2.4.1'
@@ -131,8 +121,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.4.1-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - task: DotNetCoreCLI@2
     displayName: 'E2E tests for Spark 2.4.3'
@@ -142,8 +130,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.4.3-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - task: DotNetCoreCLI@2
     displayName: 'E2E tests for Spark 2.4.4'
@@ -153,8 +139,6 @@ jobs:
       arguments: '--configuration $(buildConfiguration)'
     env:
       SPARK_HOME: $(Build.BinariesDirectory)\spark-2.4.4-bin-hadoop2.7
-      HADOOP_HOME: $(Build.BinariesDirectory)\hadoop
-      DOTNET_WORKER_DIR: $(Build.ArtifactStagingDirectory)\Microsoft.Spark.Worker\netcoreapp2.1\win-x64
 
   - ${{ if and(ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
     - task: CopyFiles@2

benchmark/csharp/Tpch/Tpch.csproj

@@ -2,13 +2,8 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net461;netcoreapp2.1</TargetFrameworks>
-    <TargetFrameworks Condition="'$(OS)' != 'Windows_NT'">netcoreapp2.1</TargetFrameworks>
-    <!--
-    Uncomment the following line to build for netcoreapp3.0.
-    Don't build for netcoreapp3.0, by default, because it requires VS 16.3.
-    -->
-    <!--<TargetFrameworks>$(TargetFrameworks);netcoreapp3.0</TargetFrameworks>-->
+    <TargetFrameworks>net461;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks Condition="'$(OS)' != 'Windows_NT'">netcoreapp3.1</TargetFrameworks>
     <RootNamespace>Tpch</RootNamespace>
     <AssemblyName>Tpch</AssemblyName>
   </PropertyGroup>
@@ -22,7 +17,7 @@
   </ItemGroup>
 
   <Choose>
-    <When Condition="'$(TargetFramework)' == 'netcoreapp3.0'">
+    <When Condition="'$(TargetFramework)' == 'netcoreapp3.1'">
       <PropertyGroup>
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
       </PropertyGroup>

deployment/HDI-Spark/Notebooks/install-interactive-notebook.sh

@@ -46,7 +46,7 @@ else
     sudo add-apt-repository universe
     sudo apt-get -yq install apt-transport-https
     sudo apt-get -yq update
-    sudo apt-get -yq install dotnet-sdk-3.0
+    sudo apt-get -yq install dotnet-sdk-3.1
 
     sudo dotnet tool uninstall dotnet-try --tool-path /usr/share/dotnet-tools || true
     sudo dotnet tool install dotnet-try --add-source https://dotnet.myget.org/F/dotnet-try/api/v3/index.json --tool-path /usr/share/dotnet-tools --version 1.0.19473.13

docs/building/ubuntu-instructions.md

@@ -16,7 +16,7 @@ Building Spark .NET on Ubuntu 18.04
 
 If you already have all the pre-requisites, skip to the [build](ubuntu-instructions.md#building) steps below.
 
-  1. Download and install **[.NET Core 2.1 SDK](https://dotnet.microsoft.com/download/dotnet-core/2.1)** or the **[.NET Core 3.0 preview SDK](https://dotnet.microsoft.com/download/dotnet-core/3.0)** - installing the SDK will add the `dotnet` toolchain to your path.
+  1. Download and install **[.NET Core 3.1 SDK](https://dotnet.microsoft.com/download/dotnet-core/3.1)** - installing the SDK will add the `dotnet` toolchain to your path.
   2. Install **[OpenJDK 8](https://openjdk.java.net/install/)** 
      - You can use the following command:
        ```bash
@@ -121,43 +121,43 @@ You should see JARs created for the supported Spark versions:
   1. Build the Worker
       ```bash
       cd ~/dotnet.spark/src/csharp/Microsoft.Spark.Worker/
-      dotnet publish -f netcoreapp2.1 -r ubuntu.18.04-x64
+      dotnet publish -f netcoreapp3.1 -r linux-x64
       ```
       <details>
       <summary>&#x1F4D9; Click to see sample console output</summary>
 
       ```bash
-      user@machine:/home/user/dotnet.spark/src/csharp/Microsoft.Spark.Worker$ dotnet publish -f netcoreapp2.1 -r ubuntu.18.04-x64
+      user@machine:/home/user/dotnet.spark/src/csharp/Microsoft.Spark.Worker$ dotnet publish -f netcoreapp3.1 -r linux-x64
       Microsoft (R) Build Engine version 16.0.462+g62fb89029d for .NET Core
       Copyright (C) Microsoft Corporation. All rights reserved.
 
         Restore completed in 36.03 ms for /home/user/dotnet.spark/src/csharp/Microsoft.Spark.Worker/Microsoft.Spark.Worker.csproj.
         Restore completed in 35.94 ms for /home/user/dotnet.spark/src/csharp/Microsoft.Spark/Microsoft.Spark.csproj.
         Microsoft.Spark -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark/Debug/netstandard2.0/Microsoft.Spark.dll
-        Microsoft.Spark.Worker -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark.Worker/Debug/netcoreapp2.1/ubuntu.18.04-x64/Microsoft.Spark.Worker.dll
-        Microsoft.Spark.Worker -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark.Worker/Debug/netcoreapp2.1/ubuntu.18.04-x64/publish/
+        Microsoft.Spark.Worker -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark.Worker/Debug/netcoreapp3.1/linux-x64/Microsoft.Spark.Worker.dll
+        Microsoft.Spark.Worker -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark.Worker/Debug/netcoreapp3.1/linux-x64/publish/
       ```
 
       </details>
 
   2. Build the Samples
       ```bash
       cd ~/dotnet.spark/examples/Microsoft.Spark.CSharp.Examples/
-      dotnet publish -f netcoreapp2.1 -r ubuntu.18.04-x64
+      dotnet publish -f netcoreapp3.1 -r linux-x64
       ```
       <details>
       <summary>&#x1F4D9; Click to see sample console output</summary>
 
       ```bash
-      user@machine:/home/user/dotnet.spark/examples/Microsoft.Spark.CSharp.Examples$ dotnet publish -f netcoreapp2.1 -r ubuntu.18.04-x64
+      user@machine:/home/user/dotnet.spark/examples/Microsoft.Spark.CSharp.Examples$ dotnet publish -f netcoreapp3.1 -r linux-x64
       Microsoft (R) Build Engine version 16.0.462+g62fb89029d for .NET Core
       Copyright (C) Microsoft Corporation. All rights reserved.
 
         Restore completed in 37.11 ms for /home/user/dotnet.spark/src/csharp/Microsoft.Spark/Microsoft.Spark.csproj.
         Restore completed in 281.63 ms for /home/user/dotnet.spark/examples/Microsoft.Spark.CSharp.Examples/Microsoft.Spark.CSharp.Examples.csproj.
         Microsoft.Spark -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark/Debug/netstandard2.0/Microsoft.Spark.dll
-        Microsoft.Spark.CSharp.Examples -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark.CSharp.Examples/Debug/netcoreapp2.1/ubuntu.18.04-x64/Microsoft.Spark.CSharp.Examples.dll
-        Microsoft.Spark.CSharp.Examples -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark.CSharp.Examples/Debug/netcoreapp2.1/ubuntu.18.04-x64/publish/
+        Microsoft.Spark.CSharp.Examples -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark.CSharp.Examples/Debug/netcoreapp3.1/linux-x64/Microsoft.Spark.CSharp.Examples.dll
+        Microsoft.Spark.CSharp.Examples -> /home/user/dotnet.spark/artifacts/bin/Microsoft.Spark.CSharp.Examples/Debug/netcoreapp3.1/linux-x64/publish/
       ```
 
      </details>
@@ -166,8 +166,8 @@ You should see JARs created for the supported Spark versions:
 
 Once you build the samples, you can use `spark-submit` to submit your .NET Core apps. Make sure you have followed the [pre-requisites](#pre-requisites) section and installed Apache Spark.
 
-  1. Set the `DOTNET_WORKER_DIR` or `PATH` environment variable to include the path where the `Microsoft.Spark.Worker` binary has been generated (e.g., `~/dotnet.spark/artifacts/bin/Microsoft.Spark.Worker/Debug/netcoreapp2.1/ubuntu.18.04-x64/publish`)
-  2. Open a terminal and go to the directory where your app binary has been generated (e.g., `~/dotnet.spark/artifacts/bin/Microsoft.Spark.CSharp.Examples/Debug/netcoreapp2.1/ubuntu.18.04-x64/publish`)
+  1. Set the `DOTNET_WORKER_DIR` or `PATH` environment variable to include the path where the `Microsoft.Spark.Worker` binary has been generated (e.g., `~/dotnet.spark/artifacts/bin/Microsoft.Spark.Worker/Debug/netcoreapp3.1/linux-x64/publish`)
+  2. Open a terminal and go to the directory where your app binary has been generated (e.g., `~/dotnet.spark/artifacts/bin/Microsoft.Spark.CSharp.Examples/Debug/netcoreapp3.1/linux-x64/publish`)
   3. Running your app follows the basic structure:
      ```bash
      spark-submit \

docs/building/windows-instructions.md

@@ -20,8 +20,8 @@ Building Spark .NET on Windows
 
 If you already have all the pre-requisites, skip to the [build](windows-instructions.md#building) steps below.
 
-  1. Download and install the **[.NET Core SDK](https://dotnet.microsoft.com/download/dotnet-core/2.1)** - installing the SDK will add the `dotnet` toolchain to your path. .NET Core 2.1, 2.2 and 3.0 preview are supported.
-  2. Install **[Visual Studio 2019](https://www.visualstudio.com/downloads/)** (Version 16.3 or later). The Community version is completely free. When configuring your installation, include these components at minimum:
+  1. Download and install the **[.NET Core 3.1 SDK](https://dotnet.microsoft.com/download/dotnet-core/3.1)** - installing the SDK will add the `dotnet` toolchain to your path.
+  2. Install **[Visual Studio 2019](https://www.visualstudio.com/downloads/)** (Version 16.4 or later). The Community version is completely free. When configuring your installation, include these components at minimum:
      * .NET desktop development
        * All Required Components
          * .NET Framework 4.6.1 Development Tools
@@ -154,42 +154,42 @@ You should see JARs created for the supported Spark versions:
   1. Build the Worker
       ```powershell
       cd C:\github\dotnet-spark\src\csharp\Microsoft.Spark.Worker\
-      dotnet publish -f netcoreapp2.1 -r win10-x64
+      dotnet publish -f netcoreapp3.1 -r win-x64
       ```
       <details>
       <summary>&#x1F4D9; Click to see sample console output</summary>
 
       ```powershell
-      PS C:\github\dotnet-spark\src\csharp\Microsoft.Spark.Worker> dotnet publish -f netcoreapp2.1 -r win10-x64
+      PS C:\github\dotnet-spark\src\csharp\Microsoft.Spark.Worker> dotnet publish -f netcoreapp3.1 -r win-x64
       Microsoft (R) Build Engine version 16.0.462+g62fb89029d for .NET Core
       Copyright (C) Microsoft Corporation. All rights reserved.
 
         Restore completed in 299.95 ms for C:\github\dotnet-spark\src\csharp\Microsoft.Spark\Microsoft.Spark.csproj.
         Restore completed in 306.62 ms for C:\github\dotnet-spark\src\csharp\Microsoft.Spark.Worker\Microsoft.Spark.Worker.csproj.
         Microsoft.Spark -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark\Debug\netstandard2.0\Microsoft.Spark.dll
-        Microsoft.Spark.Worker -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.Worker\Debug\netcoreapp2.1\win10-x64\Microsoft.Spark.Worker.dll
-        Microsoft.Spark.Worker -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.Worker\Debug\netcoreapp2.1\win10-x64\publish\
+        Microsoft.Spark.Worker -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.Worker\Debug\netcoreapp3.1\win-x64\Microsoft.Spark.Worker.dll
+        Microsoft.Spark.Worker -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.Worker\Debug\netcoreapp3.1\win-x64\publish\
       ```
 
       </details>
   2. Build the Samples
       ```powershell
       cd C:\github\dotnet-spark\examples\Microsoft.Spark.CSharp.Examples\
-      dotnet publish -f netcoreapp2.1 -r win10-x64
+      dotnet publish -f netcoreapp3.1 -r win-x64
       ```
       <details>
       <summary>&#x1F4D9; Click to see sample console output</summary>
 
       ```powershell
-      PS C:\github\dotnet-spark\examples\Microsoft.Spark.CSharp.Examples> dotnet publish -f netcoreapp2.1 -r win10-x64
+      PS C:\github\dotnet-spark\examples\Microsoft.Spark.CSharp.Examples> dotnet publish -f netcoreapp3.1 -r win10-x64
       Microsoft (R) Build Engine version 16.0.462+g62fb89029d for .NET Core
       Copyright (C) Microsoft Corporation. All rights reserved.
 
         Restore completed in 44.22 ms for C:\github\dotnet-spark\src\csharp\Microsoft.Spark\Microsoft.Spark.csproj.
         Restore completed in 336.94 ms for C:\github\dotnet-spark\examples\Microsoft.Spark.CSharp.Examples\Microsoft.Spark.CSharp.Examples.csproj.
         Microsoft.Spark -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark\Debug\netstandard2.0\Microsoft.Spark.dll
-        Microsoft.Spark.CSharp.Examples -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.CSharp.Examples\Debug\netcoreapp2.1\win10-x64\Microsoft.Spark.CSharp.Examples.dll
-        Microsoft.Spark.CSharp.Examples -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.CSharp.Examples\Debug\netcoreapp2.1\win10-x64\publish\
+        Microsoft.Spark.CSharp.Examples -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.CSharp.Examples\Debug\netcoreapp3.1\win-x64\Microsoft.Spark.CSharp.Examples.dll
+        Microsoft.Spark.CSharp.Examples -> C:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.CSharp.Examples\Debug\netcoreapp3.1\win-x64\publish\
       ```
 
       </details>
@@ -198,8 +198,8 @@ You should see JARs created for the supported Spark versions:
 
 Once you build the samples, running them will be through `spark-submit` regardless of whether you are targeting .NET Framework or .NET Core apps. Make sure you have followed the [pre-requisites](#pre-requisites) section and installed Apache Spark.
 
-  1. Set the `DOTNET_WORKER_DIR` or `PATH` environment variable to include the path where the `Microsoft.Spark.Worker` binary has been generated (e.g., `c:\github\dotnet\spark\artifacts\bin\Microsoft.Spark.Worker\Debug\net461` for .NET Framework, `c:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.Worker\Debug\netcoreapp2.1\win10-x64\publish` for .NET Core)
-  2. Open Powershell and go to the directory where your app binary has been generated (e.g., `c:\github\dotnet\spark\artifacts\bin\Microsoft.Spark.CSharp.Examples\Debug\net461` for .NET Framework, `c:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.CSharp.Examples\Debug\netcoreapp2.1\win10-x64\publish` for .NET Core)
+  1. Set the `DOTNET_WORKER_DIR` or `PATH` environment variable to include the path where the `Microsoft.Spark.Worker` binary has been generated (e.g., `c:\github\dotnet\spark\artifacts\bin\Microsoft.Spark.Worker\Debug\net461` for .NET Framework, `c:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.Worker\Debug\netcoreapp3.1\win-x64\publish` for .NET Core)
+  2. Open Powershell and go to the directory where your app binary has been generated (e.g., `c:\github\dotnet\spark\artifacts\bin\Microsoft.Spark.CSharp.Examples\Debug\net461` for .NET Framework, `c:\github\dotnet-spark\artifacts\bin\Microsoft.Spark.CSharp.Examples\Debug\netcoreapp3.1\win1-x64\publish` for .NET Core)
   3. Running your app follows the basic structure:
      ```powershell
      spark-submit.cmd `

docs/getting-started/ubuntu-instructions.md

@@ -4,7 +4,7 @@ These instructions will show you how to run a .NET for Apache Spark app using .N
 
 ## Pre-requisites
 
-- Download and install the following: **[.NET Core 2.1 SDK](https://dotnet.microsoft.com/download/dotnet-core/2.1)** | **[OpenJDK 8](https://openjdk.java.net/install/)** | **[Apache Spark 2.4.1](https://archive.apache.org/dist/spark/spark-2.4.1/spark-2.4.1-bin-hadoop2.7.tgz)**
+- Download and install the following: **[.NET Core 3.1 SDK](https://dotnet.microsoft.com/download/dotnet-core/3.1)** | **[OpenJDK 8](https://openjdk.java.net/install/)** | **[Apache Spark 2.4.1](https://archive.apache.org/dist/spark/spark-2.4.1/spark-2.4.1-bin-hadoop2.7.tgz)**
 - Download and install **[Microsoft.Spark.Worker](https://github.com/dotnet/spark/releases)** release:
     - Select a **[Microsoft.Spark.Worker](https://github.com/dotnet/spark/releases)** release from .NET for Apache Spark GitHub Releases page and download into your local machine (e.g., `~/bin/Microsoft.Spark.Worker`).
     - **IMPORTANT** Create a [new environment variable](https://help.ubuntu.com/community/EnvironmentVariables) `DOTNET_WORKER_DIR` and set it to the directory where you downloaded and extracted the Microsoft.Spark.Worker (e.g., `~/bin/Microsoft.Spark.Worker`).