HDFS XML File Writer Output Adapter Sample

Contents

About This Sample
Initial Setup
Importing This Sample into StreamBase Studio
Running This Sample in StreamBase Studio
Sample Location

About This Sample

This sample demonstrates the usage of the Spotfire Streaming XML File Writer Adapter for Apache Hadoop Distributed File System (HDFS), which is an embedded adapter suitable for streaming tuples to a text file formatted with XML tags.

Initial Setup

You must open the XMLFileWriterTest.sbapp file in the src/main/eventflow/packageName folder. Select the Parameters tab and edit the value to represent both your current HDFS setup and where you would like to store the sample data.

Importing This Sample into StreamBase Studio

In StreamBase Studio, import this sample with the following steps:

  • From the top-level menu, select File>Import Samples and Community Content.

  • Enter hdfs to narrow the list of options.

  • Select HDFS XML file output adapter from the Large Data Storage and Analysis category.

  • Click Import Now.

StreamBase Studio creates a project for the sample.

Running This Sample in StreamBase Studio

  1. In the Project Explorer view, open the sample you just loaded.

    If you see red marks on a project folder, wait a moment for the project to load its features.

    If the red marks do not resolve themselves after a minute, select the project, right-click, and select Maven>Update Project from the context menu.

  2. Open the src/main/eventflow/packageName folder.

  3. Open the XMLFileWriterTest.sbapp file. In the EventFlow editor, click the XMLFileWriter adapter icon to open its Properties view.

  4. In the Adapter Properties tab, change File Name to point to a location on your machine where you want the log to be written when the application is run.

  5. Make sure the application is the currently active tab in the EventFlow Editor.

    Click the Run button. This opens the SB Test/Debug perspective and starts the module.

  6. In the SB Test/Debug perspective, select the Manual Input tab.

  7. Enter a valid integer for a and click Send Data.

  8. When done, press F9 or click the Terminate EventFlow Fragment button.

  9. The file specified in Parameters HDFS_FILE_PATH will now contain tuples formatted as follows: 

    <tuple>
<a>2</a>
</tuple>

Sample Location

When you load the sample into StreamBase® Studio, Studio copies the sample project's files to your Studio workspace, which is normally part of your home directory, with full access rights.

Important

Load this sample in StreamBase® Studio, and thereafter use the Studio workspace copy of the sample to run and test it, even when running from the command prompt.

Using the workspace copy of the sample avoids permission problems. The default workspace location for this sample is: 

studio-workspace/sample_adapter_embedded_hdfsxmlfilewriter

See Default Installation Directories for the default location of studio-workspace on your system.