HDFS File Reader Input Adapter Sample

About This Sample

This adapter sample illustrates the use of the Spotfire Streaming Text File Reader Adapter for Apache Hadoop Distributed File System (HDFS) by reading a file and emitting a tuple that contains the file's contents in a string field.

Initial Setup

The MyFile.txt file used in this sample must be placed on your HDFS file system before this sample can run.

You must also open the filereader.sbapp file in the src/main/eventflow/packageName folder. Select the Parameters tab and edit the HDFS_FILE_PATH and HDFS_USER values to represent your HDFS setup, as well as to be able to access the required files.

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 File reader input adapter from the Large Data Storage and Analysis category.

  • Click Import Now.

StreamBase Studio creates a project for this 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 filereader.sbapp file and click the Run button. This opens the SB Test/Debug perspective and starts the module.

  4. In the Manual Input view, click Send Data to send the default null tuple.

  5. In the Output Streams view, observe tuples emitted on the Status and Data output streams, the latter of which contains the contents of the configured default file, MyFile.txt.

  6. Press F9 or click the Terminate EventFlow Fragment button.

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.


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:


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