Both are about the same festival. Very interestingly, Krishna Janmaashtami gives a South Indian version. 'little feet drawn with flour paste' afaik, is done only in the South. Likewise Gokulashtami, Sreekrishna jayanyti (incorrectly mentioned in the article as Sree jayanti are terms used in the South. Janmashtami  gives a northern perspective and how it is celebrated there. Sounds confusing ? -)