The vMatrix: A Network Of Virtual Machine Monitors For Dynamic Content Distribution

Amr A. AwadallahMendel Rosenblum{aaa,mendel}@cs.stanford.edu

Stanford University – Computer Systems Lab – WCW 2002

Stanford University – CSL – WCW 2002

What is The vMatrix?

Stanford University – CSL – WCW 2002

Problem Statement

Motivation: To enable distribution of dynamic content.(40% of web requests)

Definition:Dynamic content is web pages which are constructed by programs that execute on the server at the time a request is made. (e.g. http://maps.yahoo.com)

Stanford University – CSL – WCW 2002

Advantages of Distribution

• Faster Response Time

• Higher Availability

• Absorbing Flash Crowds

• Network Bandwidth Savings

• Lower Total Cost of Ownership

Stanford University – CSL – WCW 2002

Today Is Static Mirroring

Stanford University – CSL – WCW 2002

Dynamic Content Distribution

Stanford University – CSL – WCW 2002

Two Tier Architecture

Stanford University – CSL – WCW 2002

Main Problem

It is very hard to copy services due to all the dependencies that code has on system libraries, third-party modules, operating systems, and server hardware.

Amended Motivation:

To enable distribution of server code with minimal application, code, or operating system changes (i.e. backward compatibility with existing implementations)

Stanford University – CSL – WCW 2002

Virtual Machine Monitors

Virtual Machine Monitor

Real Machine (CPU, Memory, Disks, Network)

Virtual Machine 1:vCPU, vMem, vDisk, vNet

OS1: Windows 2000

Virtual Machine 2:vCPU, vMem, vDisk, vNet

OS2: Linux

MySQL, ApacheOracle, IIS

Stanford University – CSL – WCW 2002

Proposed Solution

A network for delivering virtual machines (VMs) between real machines (RMs) running the virtual machine monitor (VMM) software.

Stanford University – CSL – WCW 2002

Distinguishing Advantage• Backward Compatibility

Disadvantage• VM files are very large (order of

gigabytes)!

Stanford University – CSL – WCW 2002

Challenges: Mobility (NAT)

VMM

RMVM Agent

VM1 VM2192.168.1.10

NAT/LBInternet64.58.77.28

DNSmaps.yahoo.com 64.58.77.28

Stanford University – CSL – WCW 2002

Challenges: Security (VPNs)

VMM

VM1 VM2

RMVM Agent

VPNIntranet

DNS

192.168.1.10

FirewallInternet64.58.77.28

172.21.162.9

c009.proxy.yahoo.com

maps.yahoo.com 64.58.77.28

NAT/LBInternet64.58.77.28

Stanford University – CSL – WCW 2002

Two Tier Challenges• Response Time

FRONT END BACK END

N1

FRONT END

N1

BACK END

N2

BACK END

• Perception!

Stanford University – CSL – WCW 2002

Two Tier Challenges• Availability

FRONT END BACK END

Stanford University – CSL – WCW 2002

Two Tier Challenges• Replication

BACK ENDFRONT END

FRONT END

FRONT END

Stanford University – CSL – WCW 2002

Related Work

• Active Proxy Caches (ICAP, Active cache, OPES)

• App Servers (WebSphere, Dynamo, WebLogic)

• Java Virtual Machine (J#/C#/.Net)

• Light Weight OSes (Denali, Xenoservers)

• OS Virtualization (Ensim, Ejasent, EXETender)

• Portable Channel Representations (e.g. RPMs)

Stanford University – CSL – WCW 2002

Current & Future Work

• Global Server Placement Optimization

• VM Scheduling per RM

• Server Multiplexing

• Compute Utility (The Collective)

• ROC: Virtual Hot Standbys

• Internet Scale Applications Characteristics

Stanford University – CSL – WCW 2002

Conclusion

Using off the shelf technologies available today it is possible to build a network for delivering virtual machines between real machines hence solving the dynamic content distribution problem without requiring significant architectural changes.