Amazon EC2 各種虛擬化技術的效能

Brendan Gregg 整理了 Amazon EC2 的各種虛擬化技術以及效能的比較:「AWS EC2 Virtualization 2017」,從他做的這張圖可以看到最新的兩個技術 (編號 7 與 8) 的效能相當好:

主要分成三種虛擬化技術:

  • Virtualized in Software: While this can support an unmodified guest OS, many operations are emulated and slow. Apps may run 2x to 10x slower, or worse.
  • Paravirtualization: The hypervisor provides efficient hypercalls, and the guest OS uses drivers and kernel modifications to call these hypercalls. It's using software and coordination between the hypervisor and guest to improve performance. I'd expect measurable overhead of 10% to 50% (depending on the PV type and workload).
  • Virtualized in Hardware: Hardware support for virtualization, and near bare-metal speeds. I'd expect between 0.1% and 1.5% overhead.

用硬體虛擬化的過程... 然後最後也推出 bare metal 的機器 XD

Amazon EC2 的 C5 改跑 KVM

前幾天提到的「Amazon EC2 的 C5 家族...」講到 Amazon EC2 推出 C5 系列帶來的效能與價錢的提昇,後來在 The Register 上看到「AWS adopts home-brewed KVM as new hypervisor」這邊提到更多東西,而且有些還頗有趣的...

首先是 Amazon EC2 FAQs 裡面就有提到的,C5 跑的是 KVM,而不像以前是以 Xen 為底:

Q. What is the underlying hypervisor on C5 instances?
C5 instances use a new EC2 hypervisor that is based on core KVM technology.

另外一點比較有疑慮,是 The Register 提到 IntelAmazon 都發出新聞稿,說明 C5 是使用客製化版本的 Intel 處理器,不過看完後讀不出這個感覺...:「Intel Xeon Scalable Processors Supercharge Amazon Web Services’ Most Powerful Compute-Optimized Instances」、「AWS Announces Availability of C5 Instances for Amazon EC2」。

不過先不管這個... 本來 AWS 都一直圍繞在 Xen 上,這次切去 KVM 是個很值得關注的決策,可以找機會問問看為什麼要這樣換。