Tax liability question on Capital gains in Seller refince closing

[Bhanu P.]

If I sell a property with Seller financing on 30 years term/No Balloon payment at all, when am I responsible to pay the Capital gains assuming there is neither early payoff nor foreclosure?

For argument sake if there is 100K worth of capital gains, are we liable to pay taxes in the year of Sale or the capital gains portion will be prorated for the entire loan term (which is 30 years in this case)?

Please provide me any pointers or books so that I can familiarize around this topic. Thank you.