今すぐお試しください!

製品の詳細CData ADO.NET Provider for Apache Spark を確認して、無償評価版をダウンロード:

今すぐダウンロード

Provide OData Services of Spark Data from a WCF Application

This article shows how to publish an OData feed of Spark data by creating a WCF Service Application.

The CData ADO.NET Provider for Spark enables you to use the Windows Communication Foundation (WCF) framework to rapidly develop service-oriented applications that provide Spark data to OData consumers. This article shows how to create an entity data model to provide the underlying connectivity to the Spark data, as well as how to create a WCF Data Service to expose the OData service. You can then consume the feed with any OData client, for example, Power Pivot or an application that uses the CData ADO.NET Provider for OData.

Create the OData Service

Follow the steps below to create a WCF service application that will provide connectivity to Spark data via OData.

  1. Open Visual Studio and create a new project. Select the WCF Service Application template.
  2. Delete the autogenerated IService.cs and Service1.svc.
  3. Click Project -> Add New Item -> ADO.NET Entity Data Model.
  4. In the Entity Data Model wizard that is displayed, select the 'EF Designer from Database' option.
  5. In the resulting Choose Your Connection dialog, click New Connection.
  6. In the Connection properties dialog, select the CData Spark Data Source and enter the necessary credentials. A typical connection string is below:

    Server=127.0.0.1;

    SparkSQL への接続

    SparkSQL への接続を確立するには以下を指定します。

    • Server:SparkSQL をホストするサーバーのホスト名またはIP アドレスに設定。
    • Port:SparkSQL インスタンスへの接続用のポートに設定。
    • TransportMode:SparkSQL サーバーとの通信に使用するトランスポートモード。有効な入力値は、BINARY およびHTTP です。デフォルトではBINARY が選択されます。
    • AuthScheme:使用される認証スキーム。有効な入力値はPLAIN、LDAP、NOSASL、およびKERBEROS です。デフォルトではPLAIN が選択されます。

    Databricks への接続

    Databricks クラスターに接続するには、以下の説明に従ってプロパティを設定します。Note:The needed values can be found in your Databricks instance by navigating to 'Clusters', selecting the desired cluster, and selecting the JDBC/ODBC tab under 'Advanced Options'.

    • Server:Set to the Server Hostname of your Databricks cluster.
    • Port:443
    • TransportMode:HTTP
    • HTTPPath:Set to the HTTP Path of your Databricks cluster.
    • UseSSL:True
    • AuthScheme:PLAIN
    • User:'token' に設定。
    • Password:Set to your personal access token (value can be obtained by navigating to the User Settings page of your Databricks instance and selecting the Access Tokens tab).

    See the help documentation for guides to connecting in Visual Studio.

  7. Select Spark tables and views that you want OData clients to access.
  8. Click Project -> Add New Item -> WCF Data Service.
  9. Specify the data source class and configure access to the new WCF Data Service. In the example below, the Access Rule for the entities is set to All. This means that any user will be able to read and modify data.

    using System; using System.Collections.Generic; using System.Data.Services; using System.Data.Services.Common; using System.Linq; using System.ServiceModel.Web; using System.Web; namespace SparkSQLService{ public class SparkSQLDataService : DataService { public static void InitializeService(DataServiceConfiguration config) { config.SetEntitySetAccessRule("*", EntitySetRights.All); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V3; } } }
  10. Run the project. Applications that support OData can now access the Salesforce data and reflect any changes. You can access the feed in your browser. The feed will resemble the following:

Consume the OData Service from Power Pivot

You can now use the service from any OData client; for example, Excel Power Pivot.

  1. Open Excel and click on the Power Pivot Window button.
  2. A new pop-up will appear. Select the option From Data Feeds.
  3. In the resulting Table Import Wizard, enter the OData URL. For example, http://localhost:12449/SparkSQLDataService.svc/.
  4. After connecting to the OData service, click the Next button at the bottom of the window.
  5. A table listing of the available tables will appear in the next window of the wizard. Select which tables you want to import and click Finish.
  6. Click Close to import the data in Power Pivot.
 
 
ダウンロード