Rhythm is the beat and the pace of the poem.
Explanation:
A rhythm is the combination of the beat and the pace of a poem.
It is the innate musicality in the poem that dictates its flow and often the emotion of how the words of the poem feel while being read out.
The poem Life is fine is about the innate satisfaction with however life is and acceptance of its conditions for the sake of inner peace.
The tone of the poem is direct, musical, and jovial in the end with its exclamations coming after every paragraph like a refrain to show that despite everything life can be fine if we let it be fine.