Night waking

My 15 month old will wake in the middle of the night for 1-2 hours about 2-3 nights each week. Is this normal? Sometimes it seems like he thinks it is time to be awake other times he’s very sad and mopey and falls back asleep every 10 minutes but if I lay him in crib or try to walk out of the room and the floor creaks he bursts into tears. Sometimes I end up cosleeping or breastfeeding to get him to sleep. Sometimes I spend an hour rocking him. Any advice or thoughts?