Implementing single-thread processing to simplify the system architecture and reduce overhead.

Utilizing gradient boosting algorithms to predict and mitigate potential system failures.

Employing data replication across multiple nodes to ensure data is always available, even in the event of a node failure.

Applying model regularization techniques to prevent overfitting in the system's failure prediction models.

Both C (Data replication) and A (Single-thread processing) are effective strategies for ensuring fault tolerance.