Do you think China is going to play 'big brother' to N. Korea in this upcoming conflict?

I forget the word for it, but when I was a little hoodlum, we used to use 'little guys' to purposely antagonize certain people so they would get hurt and give us an excuse to fight. Do you think perhaps N. Korea is China's 'little guy'? Is China 100% in the tank with N. Korea? Is Kim just giving China the excuse they've been looking for for quite a while now?
I held stubbornly to the belief that China's leadership is 'cool headed' and objective in this situation and would go to great lengths to ensure continued peace, but I'm beginning to wonder now.