Hello World
Simple transformation to illustrate key concepts ..
Workshop - Hello World
Build a minimal transformation in Spoon. Use steps, hops, and notes. Preview data and review execution metrics.
What you’ll do
Create a transformation
Add and configure Generate Rows and Dummy
Connect steps with hops
Add a note to document the flow
Preview data from a step
Run the transformation and review results
Prerequisites: Pentaho Data Integration installed and configured
Estimated time: 10 minutes
Create a new transformation
Use any of these options to open a new transformation tab:
Select File > New > Transformation
Use
Ctrl+N(Windows/Linux) orCmd+N(macOS)
Generate Rows
Generate Rows outputs a specified number of rows. By default, the rows are empty. You can also generate static fields for test data. For example, generate 12 rows for 12 months.
Generate Rows is also useful as a single-row “starter” step.
Start Pentaho Data Integration (Spoon).
In the Design tab, expand the
Inputcategory.Drag Generate Rows onto the canvas.
Tip: You can also search for Generate Rows.
Double-click Generate Rows to open the step properties.
Ensure the following details are configured:
Step name
gr_hello-world
Limit
10
Name
message
Type
string
Value
hello world
Before you close the dialog, preview the data.
Select Preview. The Enter preview size dialog opens.
In Enter preview size, select OK.
Verify the 10 rows. Then select OK to close the preview dialog.
Select OK to close the Generate Rows dialog.
Select the
gr_hello-worldstep.Hold down the Shift key.
Drag and drop the hop onto the Dummy step.
Release the Shift key.
Add a note
Right-click anywhere on the Spoon canvas.
Select New note.
Transformation properties
To view the transformation properties:
Double-click anywhere on the canvas.
Tip: Add details in Extended description.
In Spoon, select Action > Run this transformation.
You can also select Run in the toolbar.
The Execute a transformation window opens. For this workshop, keep Local execution.
In the run dialog, open Run options.
In the Run Options panel you can set:
Run configuration (local, remote, or cluster)
Log level
Automatically save the transformation
The transformation executes.
A green tick confirms the transformation's execution, but doesn't guarantee the success of the underlying operations.
Execution Results
The Execution Results section of the window contains several different tabs that help you to see how the transformation executed, pinpoint errors, and monitor performance.
Logging tab displays logging information for each of the steps in the transformation.
Step Metrics tab provides statistics for each step in your transformation including how many records were read, written, caused an error, processing speed (rows per second) and more. This tab also indicates whether an error occurred in a transformation step.
Metrics can help identify bottlenecks (back pressure). In this example, the transformation took 30 ms. Notice gr_hello-world and Dummy initialize at the same time. Steps run in parallel in separate threads.
Preview tab displays the records.
Viewing the Transformation structure
Select the View icon (upper-left). The tree switches to the structure of the transformation.
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