Hey guys I'm hoping someone can help me.

I have a walk out basement. On the second floor (main floor) I have a deck. This deck is wood and is about 4 years new. This deck is held up by 6 wood support columns. Recently I have noticed that the wood support columns are splitting vertically.maybe half a foot to a foot in places. It happened to my neighbpur too and he put wood glue in the splits.

Is that right?
Any advice would be greatly appreciated