Ogenki desu ka

"Ogenki desu ka." is a polite Japanese
way to ask somebody "How are you?". To ask this
question even more politely, use Gokigen ikaga desu ka.

This expression is used only after meeting someone after a considerable amount of time.
It would not be used upon meeting a person for the first time, only among friends and acquaintances.

I once used this expression on a friend and he replied, "But we met yesterday." (as in "what a stupid question").