My son is also 2 and has done this a lot latley too. It is very hard to deal with. Especially the getting up at 3 or 4 am. It throws everyone's schedule into a frenzy. I know this might sound rough and I don't do it all the time, but I will put him in his room and let him cry it out for a while. He usally falls asleep after a few minutes. If he doesn't seem tired I won't do it. But I know when he's tired because he get's rough with me and his sister. And he is cranky. Normal things kids do when they are tired. If he crys over 20 or 30 minutes then I go get him and lay down with him on the couch. Just to have some quiet time.
I hope this works for you.