I have realized that giving the exercises and asking the reader to "just do them" is unfair. I might just receive blank stares from the readers when the exercise task reads "write distributed grep." After all, I am still going through the exercises myself (there, I have said it, it is hard!) - so why not do it right and teach by example, as promised? Before, I felt great about formulating a cool task (really, taking it from the Google MR paper) - again, another "I have said it!" - and though I felt great, the readers may have felt less so. Now it will be the other way around: the readers should feel good about being provided with all the needed information, and I will be working hard for that. The exercises? - It will be better to base the exercises on the already learned material, and make the exercises as some variations or extensions on it.
Another improvement is the use of GitHub. My friend Sujee used it for his HBase tutorial, and it was quite obvious that it is a good choice for sharing code.
Art: Vincent Van Gogh - Rest From Work (after Millet)