Executing part of a job several times until a condition is true

Suppose that you have a list of tasks that have to be repeated while or until a condition is true (or false). If you know about programming languages, think of this as an analogy of a while or repeat until loop. Kettle allows you to implement these kinds of iterations and this recipe explains how to do it.

For the recipe, you will use one of the transformations described in the introduction of this chapter—the transformation that generates random numbers and writes them to a file. You will execute the transformation repeatedly and keep track of the number of lines written to those files. You will continue executing the transformation as long as the total number of written lines is less than 25.

Getting ready

You will need the transformation that generates random numbers described in the introduction. If, instead of downloading the transformation you created it yourself, you will have to do a quick fix in order to make Kettle save...