Using Burstable Instances in the Public Cloud
Using Burstable Instances in the Public Cloud
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在公共云中使用突发实例
DOI：
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发表时间：
2017
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通讯作者：
G. Kesidis
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作者：
Cheng Wang;B. Urgaonkar;N. Nasiriani;G. Kesidis
Amazon EC2和Google Compute Engine（GCE）最近引入了一类新的虚拟机，称为“可突发”实例，甚至比最小的传统/常规实例更便宜。这些较低的价格伴随着平均容量的减少和方差的增加。使用EC2和GCE的测量，我们确定了突发实例的资源容量动态的关键特质，将它们与其他实例类型区分开来。最重要的是，这些实例的某些资源似乎是由确定性令牌桶之类的机制来管理的。我们发现，管理这些监管机制的参数提供者的披露类型大相径庭：充分披露（例如，EC2 t2实例的CPU容量）、部分公开（例如，GCE共享核心实例的CPU容量和远程磁盘IO带宽），或者不公开（EC2 t2实例的网络带宽）。租户将这些变化建模为随机现象（如最近的一些工作所示）可能会做出次优的采购和运营决策。我们提出了建模技术的租户，通过简单的离线测量来推断这些监管机制的属性。我们还提供了两个案例研究，说明在EC2上操作时，某些memcached工作负载如何从我们的建模中受益：（i）利用可突发实例上的流行内容的备份来增强由SPOT实例提供的廉价但低可用性的存储器内存储，以及（ii）多个可突发实例的时间复用以实现CPU或网络带宽（以及吞吐量）相当于更昂贵的常规EC2实例。
Amazon EC2 and Google Compute Engine (GCE) have recently introduced a new class of virtual machines called "burstable" instances that are cheaper than even the smallest traditional/regular instances. These lower prices come with reduced average capacity and increased variance. Using measurements from both EC2 and GCE, we identify key idiosyncrasies of resource capacity dynamism for burstable instances that set them apart from other instance types. Most importantly, certain resources for these instances appear to be regulated by deterministic token bucket like mechanisms. We find widely different types of disclosures by providers of the parameters governing these regulation mechanisms: full disclosure (e.g., CPU capacity for EC2 t2 instances), partial disclosure (e.g., CPU capacity and remote disk IO bandwidth for GCE shared-core instances), or no disclosure (network bandwidth for EC2 t2 instances). A tenant modeling these variations as random phenomena (as some recent work suggests) might make sub-optimal procurement and operation decisions. We present modeling techniques for a tenant to infer the properties of these regulation mechanisms via simple offline measurements. We also present two case studies of how certain memcached workloads might benefit from our modeling when operating on EC2 by: (i) augmenting cheap but low availability in-memory storage offered by spot instances with backup of popular content on burstable instances, and (ii) temporal multiplexing of multiple burstable instances to achieve the CPU or network bandwidth (and thereby throughput) equivalent of a more expensive regular EC2 instance.