Raghavan, AjaykrishnaChandra, AbhishekWeissman, Jon2020-09-022020-09-022014-01-13https://hdl.handle.net/11299/215940Many cloud providers offer an array of storage services that represent different points along the performance, reliability, cost, and durability spectrum. However, an application must manage the complexity of different interfaces to these storage services and their diverse policies, if it needs the composite benefits of multiple storage tiers. We believe it is possible to provide the benefits of customized tiered cloud storage to applications without compromising on simplicity. In this paper, we introduce Tiera, a system that enables the specification of multi-tiered cloud storage instances that are flexible, easy-to-use, and enable a rich array of storage policies and desired metrics to be realized. Tiera’s novelty lies in the first-class support for encapsulated tiered cloud storage, event-driven control, and support for runtime replacement and addition of policies and tiers. Tiera enables an application to realize a desired metric (e.g., low latency or low cost) by selecting different storage services that constitute an instance, and tune different parameters that impact a metric. Tiera can also be used to compare different storage configurations and policies, before picking an optimal policy for a particular workload. Through a prototype implemented on Amazon cloud services, we illustrate the benefits of Tiera achieved with minimal overhead.en-USReport