  Today's cloud service architectures follow a "one size fits all" deployment
strategy where the same service version instantiation is provided to the end
users. However, consumers are broad and different applications have different
accuracy and responsiveness requirements, which as we demonstrate renders the
"one size fits all" approach inefficient in practice. We use a production-grade
speech recognition engine, which serves several thousands of users, and an open
source computer vision based system, to explain our point. To overcome the
limitations of the "one size fits all" approach, we recommend Tolerance Tiers
where each MLaaS tier exposes an accuracy/responsiveness characteristic, and
consumers can programmatically select a tier. We evaluate our proposal on the
CPU-based automatic speech recognition (ASR) engine and cutting-edge neural
networks for image classification deployed on both CPUs and GPUs. The results
show that our proposed approach provides an MLaaS cloud service architecture
that can be tuned by the end API user or consumer to outperform the
conventional "one size fits all" approach.
