Facebook looks to Spiral for self-tuning, real-time services

Facebook's engineering group is developing a small, embedded C++ library called Spiral to providing the self-tuning of its data infrastructure necessary to fine-tune thousands of micro services.
Machine learning is used with Spiral to create data-driven and reactive heuristics for resource-constrained real-time services.

Facebook says software maintenance increasingly requires self-tuning capabilities because it is simply "too difficult to rewrite caching/admission/eviction policies and other manually tuned heuristics by hand."

https://code.fb.com/data-infrastructure/spiral-self-tuning-services-via-real-time-machine-learning/