Providing fault-tolerance (FT) support to Internet of Things (IoT) systems is an open challenge, with many implementations providing static, tightly coupled FT support that does not adapt and evolve like IoT systems do. This paper proposes a pluggable framework based on a microservices architecture that implements FT support as two complementary microservices: one that uses complex event processing for realtime FT detection, and another that uses online machine learning to detect fault patterns and pre-emptively mitigate faults before they are activated. We provide an early evaluation of how our framework can handle a real-world scenario.