Spark RDD Java Snippet (Sink)
KNIME Extension for Apache Spark core infrastructure version 4.3.0.v202011281457 by KNIME AG, Zurich, Switzerland
This node allows you to execute arbitrary java code to persist an existing Spark RDD e.g. by writing it to HDFS (See provided templates). Simply enter the java code in the text area.
Note, that this node also supports flow variables as input to your Spark job. To use a flow variable simply double click on the variable in the "Flow Variable List".
It is also possible to use external java libraries. In order to
include such external jar or zip files, add their location in the
"Additional Libraries" tab using the control buttons.
For details see the "Additional Libraries" tab description below.
The used libraries need to be present on your cluster and added to the class path of your Spark job server.
They are not automatically uploaded!
You can define reusable templates with the "Create templates..." button. Templates are stored in the users workspace by default and can be accessed via the "Templates" tab. For details see the "Templates" tab description below.
Options
Java Snippet
- Flow Variable List
- The list contains the flow variables that are currently available at the node input. Double clicking any of the entries will insert the respective identifier at the current cursor position (replacing the selection, if any).
- Snippet text area
Enter your java code here.
The JavaSparkContext can be accessed via the method input parameter sc. The input JavaRDD<Row> can be accessed via the method input parameter rowRDD.
Flow variables:
You can access input flow variables by defining them in the Input table. To define a flow variable simply double click on the variable in the "Flow Variable list".You can hit ctrl+space to get an auto completion box with all available classes, methods and fields. When you select a class and hit enter a import statement will be generated if missing.
Note, that the snippet allows to define custom global variables and custom imports. To view the hidden editor parts simply click on the plus symbols in the editor.
- Input
- Define system input fields for the snippet text area. Every field will be populated with the data of the defined input during execution.
Additional Libraries
Allows you to add additional jar files to the java snippet class path.
The used libraries need to be present on your cluster and added to the class path of your Spark job server.
They are not automatically uploaded!
- Add File(s)
- Allows you to include local jar files.
- Add KNIME URL...
- Allows you to add workflow relative jar files.
Templates
Provides predefined templates and allows you to define new reusable templates by saving the current snippet state.
- Category
- Groups templates into different categories.
- Apply
- Overwrites the current node settings with the template settings.
- Java Snippet
- Preview of the template code.
- Additional Libraries
- Preview of the additional jars.
Input Ports
Best Friends (Incoming)
- Spark Joiner (50 %)
- Java Edit Variable (10 %)
- Spark DataFrame Java Snippet (10 %)
- Spark Predictor (Classification) (10 %)
- Spark k-Means (10 %)
- Show all 6 recommendations
Best Friends (Outgoing)
- Destroy Spark Context (100 %)
Workflows
06_Modularized_Spark_Scripting (KNIME Hub) - 06_Modularized_Spark_Scripting (KNIME Hub)
Installation
To use this node in KNIME, install KNIME Extension for Apache Spark from the following update site:
A zipped version of the software site can be downloaded here.
You don't know what to do with this link? Read our NodePit Product and Node Installation Guide that explains you in detail how to install nodes to your KNIME Analytics Platform.
Developers
You want to see the source code for this node? Click the following button and we’ll use our super-powers to find it for you.