PDI, also known as Kettle, is a very powerful tool. It can be used for performing typical Extract, Transform, and Load (ETL) processes. PDI gets data from different sources and manipulates it in many ways (deduplicating, filtering, cleaning, and formatting, among others), saving the data in different formats and destinations. The following diagram illustrates a very simple example of an ETL process designed with PDI:

Aside from the preceding processes, PDI serves to migrate data between applications, access and manipulate real-time data, access data in the cloud, orchestrate administrative tasks, and more.

The following are the instructions to install the PDI Community Edition (CE), irrespective of the operating system that you may be using:

• Make sure that you have JRE 8.0 installed.

• Go to the download page at: https://sourceforge.net/projects/pentaho/files/Data%20Integration/.
• Choose the latest stable release. At the time of writing this book, it is 8.1, as shown in the following screenshot:

• Download the available ZIP file, which will serve you for all platforms.
• Unzip the downloaded file in a folder of your choice (for example, c:/software/pdi or /home/pdi_user/pdi).
• Browse your disk and look for the PDI folder that was just created. You will see a folder named data-integration, with several subfolders (lib, plugins, samples, and more) and a bunch of scripts (spoon.bat, pan.bat, and others), which we will soon learn how to use.

Spoon is PDI's desktop designer tool. With Spoon, you can design, preview, and test all of your work (that is, transformations and jobs).

Before starting to work with PDI, it's advisable to take a look at the Spoon interface and do some minimal configuration. The instructions are as follows:

• Start Spoon: If your system is Windows, run Spoon.bat from within the PDI installation directory. On other platforms, such as Unix, Linux, and so on, open a Terminal window and type spoon.sh.
• The main window will show up, with a Welcome! window already open, as shown in the following screenshot:

In order to customize Spoon, do the following:

• Click on Options... in the Tools menu. A window appears, where you can change various general characteristics, as follows:

• Many of the options in this tab will not make sense to you yet. Instead of doing anything here, select the tab Look & Feel:

• Feel free to change any of the options in this tab (for example, the font color or size). Click on the OK button.
• Restart Spoon to apply the changes.

Transformations and jobs are the main PDI artifacts. Transformations are data-flow oriented entities, while jobs are task-oriented. In this book, we will start by learning all about transformations, focusing on jobs later. To get a quick idea of what, exactly, a transformation is, we will start by creating a simple one. This will also allow you to see what it's like to work with Spoon.

Our first transformation will find out the current version of PDI (Kettle), and will print the value to the log. Proceed as follows:

• On the Welcome page, click on the New transformation link, located under the WORK link group. Alternatively, press Ctrl + N.
• A new tab will appear, with the title Transformation 1. It's in this tab that you will create your work.
• To the left of the screen, under the Design tab, you'll see a tree of folders. Expand the Input folder by double-clicking on it.

• Then, left-click on the Get System Info icon, and, without releasing the button, drag and drop the selected icon to the work area (that is, the blank area that occupies almost all of the screen). You should see something like this:

• Double-click on the Get System Info icon. A configuration window will show up. Fill in the first row in the grid, as shown in the following screenshot. Note that you don't have to type the Kettle version. Instead, you can choose it from a list of available options:

• In the Design tab, double-click on the Utility folder, click on the Write to log icon, and drag and drop it to the work area.
• Put the mouse cursor over the Get System Info icon and wait until a tiny toolbar shows up, as shown in the following screenshot:

• Click on the output connector (the icon highlighted in the preceding image) and drag it towards the Write to log icon. A greyed hop is displayed.
• When the mouse cursor is over the Write to log step, release the button. A link (a hop, from now on) is created, from the first step to the second one. The screen should look as follows:

Let's add some color note to our work, as follows:

• Right-click anywhere in the work area to bring up a contextual menu.
• In the menu, select the New Note... option. A note editor will appear.
• Type a description, such as My first transformation. Select the Font style tab and choose a nice font and some colors for your note, and then click on OK. The following should be the final result:

• Save the transformation by pressing Ctrl + S. PDI will ask for a destination folder. Select the folder of your choice, and give the transformation a name. PDI will save the transformation as a file with a ktr extension (for example, sample_transformation.ktr).

Finally, let's run the transformation to see what happens:

• Click on the Run icon, located in the transformation toolbar:

• A window named Run Options will appear. Click on Run.
• At the bottom of the screen, you should see a log with the results of the execution:

When you run Spoon for the first time, a folder named .kettle is created in your home directory by default. This folder is referred to as the Kettle home directory.

The folder contains several configuration files, mainly created and updated by the different PDI tools. Among these files, there is the kettle.properties file.

The purpose of the kettle.properties file – created along with the .kettle folder, the first time you run Spoon – is to contain variable definitions with a broad scope: Java Virtual Machine. Therefore, it's the perfect place to define general settings; some examples are as follows:

• Database connection settings: host, database name, and so on
• SMTP settings: SMTP server, port, and so on
• Common input and output folders
• Directory to send log files to

Before continuing, let's add some variables to the file. Suppose that you have two folders, named C:/PDI/INPUT and C:/PDI/OUTPUT, which you will use for storing files. The objective will be to add two variables, named INPUT_FOLDER and OUTPUT_FOLDER, containing those values:

1. Locate the Kettle home directory. If you work in Windows, the folder could be C:\Documents and Settings\<your_name> or C:\Users\<your_name>, depending on which Windows version you have. If you work in Linux (or similar) or macOS, the folder will most likely be /home/<your_name>/.
2. Edit the kettle.properties file. You will see that it only contains commented sample lines.
3. You can safely remove the contents of the file and define your own variables by typing the following lines:

       INPUT_FOLDER=C:/PDI/INPUT
       OUTPUT_FOLDER=C:/PDI/OUTPUT

Save the file and restart Spoon, so that it can recognize the variables defined in the file. We will learn how to use these variables in Chapter 2, Getting Familiar with Spoon.

In this chapter, you were introduced to Pentaho Data Integration. Specifically, you learned what PDI is, and you installed the tool. You were introduced to Spoon, PDI's graphical designer tool, and you created your first transformation. You were also introduced to the Kettle home directory and the kettle.properties file, which will be used throughout the rest of the book.

In Chapter 2, Getting Familiar with Spoon, you will learn much more about the process of creating, testing, and running transformations in Spoon.