Design an MLOps strategy for the zero-downtime update of production ML models in response to real-time data shifts.

Instruction: Provide a detailed strategy that includes the identification of real-time data shifts, decision-making processes for updates, and the implementation of updates with zero downtime.

Context: This question assesses the candidate's ability to monitor and identify significant changes in data patterns in real-time, make informed decisions on when and how to update ML models without affecting the current production environment, and execute these updates seamlessly. The candidate should detail techniques for detecting data shifts, criteria for triggering model updates, strategies for testing and rolling out updates in a way that avoids downtime, and mechanisms for rollback if issues arise.