VirtualizationAbdullah Aldhamin

June 3, 2013

2

Outline

Virtualization: what and why?

Server Virtualization Offerings

Shortcoming and Challenges on SV

Sustaining Performance while Virtualizing

Future Perspective on SV

Data Center Network Virtualization, what and why?

Overview of VN Projects and how they compare with each others

Future Perspective on DC Network Virtualization

Conclusions

3

Virtualization

Virtualization Techniques, methods, approaches to create a virtual

instance of a computing resource.

Why? Advances in h/w technologies, e.g. multi-core

H/W optimization Cloud computing Economic factors

4

Server Virtualization

Key features: Multiple Isolated

5

Server Virtualization: Offerings

Improved H/W utilization Consolidation

VMs are just files Faster provisioning and deployment Better availability and BC solutions

6

Server Virtualization: Offerings

Lower TCO Longer h/w purchase cycle Smaller datacenter Lower maintenance, power, cooling … etc

7

Server Virtualization: Challenges

Performance: CPU and Network

Overhead to do virtual-related emulations A single NIC = shared bandwidth Not good for I/O bound apps Propagation delay latency

Storage Latency Needs enough physical storage power to support the

multiple VMs Memory

Amount needed for the application

8

Server Virtualization: Challenges

Scalability How many VMs can each physical server

accommodate?

Asset management Tracking a dynamic environment Service management burdens

Security Malicious access to the hypervisor means you’re

screwed up!

Single-point of failure?

9

Server Virtualization and Performance:Can we have both?

10

Virtualization and Performance

Selective virtualization

Direct assignment of physical NICs to VMs Isolation and and better I/O− Cost for more NICs and cabling− Flexibility constraints

11

Virtualization and Performance

Firmware-based I/O virtualization Virtual I/O channels connected to the same NIC No true isolation, a channel will impact all other

channels

H/W-based I/O virtualization I/O channels are built in the H/W- Vendor-specific NICs

12

Virtualization and Performance

Consolidation in a shared resource pool Allocate VMs to a resource pool instead of physical

server Dynamic resource allocation to VMs based on

workload Complexity and poor visibility on how performance

is managed Adds challenges to asset management

13

Virtualization and Performance

Management tools Help manage performance, track SLAs and set

priorities Optimize resource allocation Proactive failure assessment

Advances in processors and memory Multiple logical CPUs and improved instructions

faster comm. between hypervisor and VMs Integrate I/O memory mgmt and DMA remapping

better I/O virtualization

14

Highlights on SV Trends

Open-source tools

Joint collaboration between server virtualization vendors and processors’ manufacturers

Hardware-based hypervisor

Convergence of server, storage, desktop and apps virtualization.

15

So…

Server virtualization

Pros and Cons

How can we overcome (or minimize) the impact on performance

Future perspectives

16

Is this enough? Does it solve everything we want

from Virtualization?

17

Server Virtualization is NOT enough!

No performance isolations

Security

Poor application deployability

Limited management flexibility

No support network innovation

18

Data Center Network Virtualization

Multiple virtual networks (VNs) on top of physical network.

Challenges Addressing schemes Scalability Failure tolerance Security Resource management

19

Examples of DC Network Topologies

Conventional DC network topology

20

Examples of DC Network Topologies

Clos topology Path diversity

21

Examples of DC Network Topologies

Fat-tree topology

K=4

22

Network Basic Functionalities/Features

Packet forwarding schemes

Bandwidth guarantees

Relative bandwidth sharing

Multipathing techniques

23

Examples of Virtual NetworkProposals/Implementations

24

Traditional Data Center

Objective: isolation between tenants

Pros: Uses VLANs to provide means of isolations Uses commodity switches and popular hypervisors SPs can have their own L2 & L3 address spaces

Cons: Imposes scalability concerns

25

Diverter

Objective: to provide software-based VN solution for packet forwarding L3 network virtualization to allow tenants control

their addresses Software module VNET on every physical machine

Replaces VM MAC with physical MAC Special IP scheme (10.tenant.subnet.vm)

Lacking QoS

26

NetLord

Objective: virtual network designed to provide solution for scalability of tenants, in order to increase resource utilization and revenue

Utilizes L2 and L3 virtualization: L2+L3 encapsulation Full address-space virtualization

Uses Diverter forwarding

Uses SPAIN multipathing

27

NetLord

28

NetLord

Pros: Takes advantage of already implemented schemes

to provide basic functionalities

Cons Not all commercial off-the-shelf switches support IP

forwarding Large packet encapsulation results in more drops

and fragmentation No bandwidth guarantee

29

Oktopus

Issues with multi-tenant data center networks: Difficult application performance management Unpredictable network performance decrease app.

performance unhappy customers revenue lo$$e$

Objectives: to design virtual network abstractions and to explore the trade-off between the guarantees offered to tenants, the tenant cost and provider revenue

Key design concept: two virtual network abstractions: Virtual cluster Virtual oversubscribed cluster

30

Oktopus

Cluster

31

Oktopus

Virtual cluster

32

Oktopus

Virtual oversubscribed cluster

33

Oktopus

Pros: Increases application performance Flexibility to InP Balance between higher application performance

and lower cost

Cons Deployability: only for tree-like physical network

topologies

34

Gatekeeper

Objectives: a virtual network to provide bandwidth guarantees, and achieves high bandwidth utilization

Design features: Scalable in terms of number of VMs Predictable in terms of network performance Flexible based on minimum and maximum bandwidth

guarantees

Design elements: Minimum guaranteed rate Maximum allowed rate for each VM

35

Gatekeeper

36

Gatekeeper

Pros: Flexible bandwidth guarantees

Cons: Other performance features are not addressed Still under development Scale of experimental evaluation is small

37

Seawall

Objective: a virtual network to provide bandwidth sharing in a multi-tenant data center network

38

Seawall

Pros: Policy enforcement so no one tenant can consume

all bandwidth Dynamic nature allows for tenant requirement

change adjustment

Cons: Deployability: currently for Windows and Hyper-V

39

Project

Feature

Forwarding Scheme

Bandwidth Guarantee

Multipathing Relative BW Sharing

Traditional DC

✔ ✔

Diverter ✔

NetLord ✔ ✔

VICTOR ✔

VL2 ✔ ✔

PortLand ✔ ✔

SEC2 ✔ ✔

SPAIN ✔

Oktopus ✔

SecondNet ✔ ✔

Gatekeeper ✔

CloudNaaS ✔ ✔

Seawall ✔

NetShare ✔ ✔

Classification of Projects by Feature

40

Highlights on Research Direction

Virtualized Edge Data Center: concerned about placement of small data centers at the edge of the network to be closer to end-users

Benefits: Better QoS for delay sensitive applications Reduces network communication cost by reducing network traffic

across network providers Lower construction cost compared to large remote data centers

Challenges: Service placement problem: finding optimal trade-off between

performance and construction cost How to efficiently manage services hosted in multiple data

centers?

41

Highlights on Research Direction

Virtual data center embedding algorithms: to accommodate a high number of VDCs in data centers Dependent on how efficient virtual resources are

mapped to physical ones

Challenges: Need to consider all physical resources, in addition to

servers Dynamic nature of the demand for data center

applications Energy efficiency: how to optimize the placement of VMs

and VNs for energy efficiency?

42

Highlights on Research Direction

Network performance guarantees: The design and implementation for bandwidth

allocation schemes Find a good trade-off between maximizing network

utilization and guaranteed network performance

Data center management: Monitoring Energy management Failure detection and handling

43

Highlights on Research Direction

Security: Mitigating security vulnerabilities Monitoring and auditing infrastructure Support for multi-layer security depending on

tenants needs

44

Conclusions

Server virtualization: what and why?

Techniques to address performance issues related to server virtualization

Datacenter network virtualization: what and why?

Recent virtual network architectures: no ideal project to solve all problems!

Future perspectives on server and network virtualization research: we still have a lot to do…

45

Thank You!

46

References

Fauzi Kamoun, “Virtualizing the Datacenter Without Compromising Server Performance”, ACM Ubiquity, Vol 2009, Issue 9.

Md. Faizul Mari, et. al., “Data Center Network Virtualization: A Survey”, in IEEE Communications Surveys & Tutorials, Vol 15, pg. 909-928, Sep 2012.

[online] http://en.wikipedia.org/virtualization “Virtualization”, May 2013.

T. Benson, et. al., “CloudNaaS: A Cloud Networking Platform for Enterprise Applications”, SOCC’11, 2011.

A. Edwards, et.al., “Diverter: A New Approach to Networking Within Virtualized Infrastructures”, WREN’09, 2009.

J. Mudigonda, et. al., “SPAIN:COTS Data-Center Ethernet for Multipathing over Arbitrary Topologies,” in Proceedings ACM USENIX NSDI, April 2010.

 J. Mudigonda, et. al., “NetLord: A Scalable Multi-Tenant Network Architecture for Virtualized Datacen- ters,” in Proceedings ACM SIGCOMM, August 2011.

F. Hao, et. al., “Enhancing Dynamic Cloud-based Services using Network Virtualization,” in Proceedings ACM VISA, August 2009.