Thesis Proposal for their Master Degree

[Fact]

Anybody took Thesis Proposal for their Master Degree exit requirement (especially in the computer field)? I was wondering if it takes like 2-3 years to complete or 1 is enough or even less. Anybody knows the process to it all? Comprehensive exam (3 finals in one – tough cookie) or Thesis(research paper, process unknown to me) – this is the question!
Thanks