Paper: The CPU Scheduler in VMware vSphere 5.1

Posted by Kenneth van Surksum   |   Monday, January 28th, 2013   |  

VMware has released a paper titled: “The CPU Scheduler in VMware vSphere 5.1“. The paper which contains 26 pages provides detailed explanations of ESXi CPU scheduling policies to help vSphere users who want to understand how virtual machines are scheduled.

The CPU scheduler is an essential component of vSphere 5.x. All workloads running in a virtual machine must be scheduled for execution and the CPU scheduler handles this task with policies that maintain fairness, throughput, responsiveness, and scalability of CPU resources.

clip_image001

The paper contains the following sections:

  • Executive Summary
  • Introduction
  • Terminology
  • CPU Scheduler Overview
  • Proportional Share-Based Algorithm
  • Relaxed Co-Scheduling
  • Load Balancing
  • Policy on Hyper-Threading
  • NUMA Scheduling Policy
  • Experiments
  • Conclusion
  • References

The ESXi CPU scheduler achieves fair distribution of compute resources among many virtual machines without compromising system throughput and responsiveness. Relaxed co-scheduling is a salient feature that enables both correct and efficient execution of guest instructions with low overhead. The ESXi CPU scheduler is highly scalable and supports very big systems and wide virtual machine.

vSphere 5.1 optimizes the load-balancing algorithm introduced in 5.0. It results in noticeable reductions in CPU scheduling overhead. A policy change on hyper-threaded systems enables out-of-the-box performance of 5.1 exceeding that of a tuned version of vSphere 4.1. No special tuning is required to achieve the best performance for most common application workloads. The irtual NUMA feature introduced in 5.0 can significantly improve performance of workloads that are optimized for a NUMA environment. With vNUMA, virtual machines of any size can display optimal performance on a NUMA system. The vNUMA feature is shown to significantly improve the performance of SPEC OMP workloads. Such improvement closes the performance gap between the virtual and the native environment for high-performance-computing (HPC) workloads.


Labels: ,

blog comments powered by Disqus


virtualization.info Newest articles
Release: WinDocks 1.0

April 5th, 2016

Yesterday, Bellevue (WA) based company WinDocks, released version 1.0 of its homonymous Docker engine for Windows.
The company, founded by a small group of former Microsoft’s employees, rides Docker’s…

LANDesk Acquires AppSense

March 17th, 2016

LANDesk Software, founded in 1985 and headquartered in Salt Lake City, Utah , provides systems management, security management, service management, asset management and process management solutions with a strong focus…

Release: Red Hat Enterprise Virtualization 3.6

March 15th, 2016

Last week open source giant Red Hat announced the availability of version 3.6 of its KVM-based virtualization platform Red Hat Enterprise Virtualization (RHEV).
While this new release provides the expected…

Docker acquires Conductant

March 4th, 2016

Yesterday Docker announced to have acquired a semi-stealth startup called Conductant, focused on workloads orchestration.

Both Conductant’s founders, Bill Farner and David Chung, have significant enterprise experience coming from…

Cisco acquires CliQr

March 1st, 2016

Today Cisco announced the intent to acquire CliQr Technologies Inc., a privately held company based in San Jose, CA.
CliQr is one of the most promising startups in the Cloud…

Release: VMware vCloud Suite 7 and vRealize Suite 7

February 11th, 2016

Yesterday VMware announced version 7 of both its vCloud and vRealize suites, confirming its efforts to be relevant in the CMPs (Cloud Management Platforms) space.
vRealize Suite 7 is made…

Platform9 adds Multi-Region & Multi-Hypervisor management into Managed OpenStack

February 11th, 2016

Platform9 solutions leverages a mix of SaaS and on premises Virtual Appliance to provide into supported environments capabilities typical of Cloud Management Platforms (CMPs) such self-service provisioning, monitoring, configuration…

VMware announces vRealize Log Insight 3.3

February 10th, 2016

Log Insight is a log aggregation, management and analisys tool, that VMware first introduced in 2013 and now is fiercely competing against Splunk.
Today the company announced Log Insight 3.3…

Microsoft releases Azure Stack TP1

February 1st, 2016

During Ignite 2015, back in September, Microsoft announced Microsoft Azure Stack as the building block for its hybrid cloud strategy.
What Microsoft is saying with this move is that, despite…

Release: Ansible 2.0

January 14th, 2016

Ansible is an IT automation tool especially popular within the developers’ community, thanks to its simplicity and agentless nature.
Three months away from its acquisition by Red Hat the company announced…

Nutanix goes Public

December 23rd, 2015

Nutanix is a provider of converged infrastructure, basically a physical server containing both compute and storage driven by an Installed Hypervisor of choice, this server, called a node can…

Release: VMware vRealize Automation 7 and VMware vRealize Business Standard 7

December 23rd, 2015

Last week VMware finally completed the first major update of VMware vRealize Suite, its well known cloud management solution, releasing in GA both vRealize Automation 7 and vRealize Business Standard…

WhatMatrix.com goes Live

December 15th, 2015

virtualization.info has been following Virtualization Matrix since its early steps and we recently wrote about its crowdsourced-powered heir: WhatMatrix.
Today we are happy to report that its community, formed…

Microsoft loves Red Hat: The business implications

November 18th, 2015

As you may have heard, Microsoft recently announced its “historical” partnership with Red Hat, something that a number of analysts already claimed as a milestone for both companies but especially for…

 
Monthly Archive