OFC: an opportunistic caching system for FaaS platforms
OFC: an opportunistic caching system for FaaS platforms
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DOI：
10.1145/3447786.3456239
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发表时间：
2021-04
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影响因子：
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通讯作者：
Djob Mvondo;Mathieu Bacou;Kevin Nguetchouang;Lucien Ngale;Stéphane Pouget;Josiane Kouam;Renaud Lachaize-R
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作者：
Djob Mvondo;Mathieu Bacou;Kevin Nguetchouang;Lucien Ngale;Stéphane Pouget;Josiane Kouam;Renaud Lachaize-R
基于“作为服务的功能”（FAA）范式的云应用程序变得非常流行。但是，由于其无状态性质，他们必须经常与外部数据存储互动，这限制了其性能。为了减轻此问题，我们介绍了OFC，这是一种透明，垂直和水平的弹性弹性内存中的FAAS平台，分布在工人节点上。 OFC通过利用两种常见的资源浪费来源来提供这些好处：（i）大多数云租户过度投放了为其功能保留的内存资源，因为它们的足迹非依赖于输入的依赖性依赖性，并且（ii）FAAS提供商使功能沙箱保持活力几分钟以避免感冒开始。使用针对典型功能输入数据类别（例如多媒体格式）调整的机器学习模型，OFC估算了每个功能调用所需的实际内存资源，并ho积ho积给饲喂缓存的剩余能力。我们基于开放式FAAS平台，Swift持久对象存储和Ram-Cloud内存商店的增强功能来构建OFC原型。使用一组工作负载，我们表明OFC分别提高了82％和60％的单级和管道功能的执行时间。
Cloud applications based on the "Functions as a Service" (FaaS) paradigm have become very popular. Yet, due to their stateless nature, they must frequently interact with an external data store, which limits their performance. To mitigate this issue, we introduce OFC, a transparent, vertically and horizontally elastic in-memory caching system for FaaS platforms, distributed over the worker nodes. OFC provides these benefits cost-effectively by exploiting two common sources of resource waste: (i) most cloud tenants overprovision the memory resources reserved for their functions because their footprint is non-trivially input-dependent and (ii) FaaS providers keep function sandboxes alive for several minutes to avoid cold starts. Using machine learning models adjusted for typical function input data categories (e.g., multimedia formats), OFC estimates the actual memory resources required by each function invocation and hoards the remaining capacity to feed the cache. We build our OFC prototype based on enhancements to the OpenWhisk FaaS platform, the Swift persistent object store, and the RAM-Cloud in-memory store. Using a diverse set of workloads, we show that OFC improves by up to 82 % and 60 % respectively the execution time of single-stage and pipelined functions.