Contents
The basic adapter sample illustrates the use of the Spotfire Streaming File Writer for Apache Hadoop Distributed File System (HDFS) by taking in a tuple and writing one of its fields contents to a file.
The advanced adapter sample illustrates reading from a sample input file multiple times and writing that data back out in various compression formats.
You must also open the FileWriterBasic.sbapp or the FileWriterAdvanced.sbapp file in the src/main/eventflow/ 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.
packageName
The SampleIn.txt file used in the FileWriterAdvanced.sbapp sample must be placed on your HDFS file system before this sample can run.
In StreamBase Studio, import this sample with the following steps:
-
From the top-level menu, select >.
-
Enter
hdfsto narrow the list of options. -
Select HDFS file writer output adapter from the Large Data Storage and Analysis category.
-
Click .
StreamBase Studio creates a single project containing the sample files.
-
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 > from the context menu.
-
Open the
src/main/eventflow/folder.packageName -
Open the
FileWriterBasic.sbappfile and click the
Run button. This opens the SB Test/Debug perspective and starts the module.
-
In the Manual Output view, switch the
StreamtoData, then enter a string value such astest, and then click to send a data tuple to be written to the file. Repeat for as many lines as you wish. -
In the Output Streams view, observe tuples emitted on the
Statusoutput streams indicating actions performed to the file. -
In the Manual Output view, switch the
StreamtoControl, then enterCloseinto theCommandfield. Click to send a control tuple (which closes the current file for writing). -
Press F9 or click the
Terminate EventFlow Fragment button.
-
This demo will have now created a file in your project called
SampleOut.txtcontaining the lines of data you submitted.
-
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 > from the context menu.
-
Open the
src/main/eventflow/folder.packageName -
Open the
FileWriterAdvanced.sbappfile and click the Run button. This opens the SB Test/Debug perspective and starts the module.
-
In the Output Streams view, observe tuples emitted on the
Statusoutput streams indicating actions performed to the files. -
Press F9 or click the
Terminate EventFlow Fragment button.
-
This demo will have now created multiple files in your project:
-
Sample.gz- This file is a GZip compressed file created from theSampleIn.txtfile. -
Sample.gz2- This file is a BZip2 compressed file created from theSampleIn.txtfile. -
Sample.zip- This file is a Zip compressed file created from theSampleIn.txtfile. -
SampleOut.txt- This file is a un-compressed file created from theSampleIn.txtfile.
-
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_hdfsfilewriterSee Default Installation Directories for the default location of studio-workspace on your system.