1. Increasing Application Performance In Virtual Environments Through Run-time Inference and Adaptation
Ananth I. Sundararaj
Ashish Gupta
Peter A. Dinda
Prescience Lab
Department of Computer Science
Northwestern University

2. Summary
Dynamically adapt unmodified applications on unmodified operating systems in virtual environments to available resources
The adaptation mechanisms are application independent and controlled automatically without user or developer help
Demonstrate the feasibility of adaptation at the level of collection of VMs connected by Virtual Networks
Show that its benefits can be significant for two classes of applications

3. Outline Virtual machine grid computing Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET, VTTIF Adaptive virtual network
Evaluation
Summary

4. Virtual Machines What are they?
Virtual Machine Grid Computing
Aim
Deliver arbitrary amounts of computational power to perform distributed and parallel computations 1
Traditional Paradigm
New Paradigm 2 5
Grid Computing using virtual machines
Resource multiplexing using OS level mechanism
Grid Computing 4 3a 3b 6a
Problem1: 6b
Virtual Machines What are they?
Complexity from resource user’s perspective
Solution
Problem2:
How to leverage them?
Complexity from resource owner’s perspective

5. Virtual Machines Virtual machine monitors (VMMs)
Raw machine is the abstraction
VM represented by a single
image
VMware GSX Server

6. The Simplified Virtuoso Model
Virtual networking ties the machine back to user’s home network
User’s LAN
Specific hardware and performance VM
Basic software installation available
Orders a raw machine
Virtuoso continuously monitors and adapts
User

7. User’s View in Virtuoso Model
User’s LAN VM
User

8. Outline Virtual machine grid computing Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET, VTTIF Adaptive virtual network
Evaluation
Summary

9. VNET: A bridge with long wires
Virtual Networks
VM traffic going out on foreign LAN
Foreign hostile
LAN X
User’s friendly
LAN
IP network
Virtual Machine
Host
A machine is suddenly plugged into a foreign network. What happens?
Does it get an IP address?
Is it a routeable address?
Does firewall let its traffic
through? To any port?
Proxy
VNET: A bridge with long wires

10. A VNET Link Ethernet Packet Captured by Interface in Promiscuous mode
First link
Second link (to proxy)
“Host Only” Network
VM 1
VM 2
“eth0”
“eth0”
ethy
ethz
vmnet0
vmnet0
VNET
IP Network
VNET
Ethernet Packet Tunneled
over TCP/SSL Connection
Host
Host
Ethernet Packet is Matched against the Forwarding Table on that VNET
Ethernet Packet is Matched against the Forwarding Table on that VNET
Local traffic matrix inferred by VTTIF
Periodically sent to the VNET on the Proxy

11. Virtual Topology and Traffic Inference Framework (VTTIF) Operation
Ethernet-level traffic monitoring
VNET daemons collectively aggregate
a global traffic matrix for all VMs
Explain the visualization generated.
Finally a one step process:
Doitall [parallel program name] and it went through all the steps and displayed the infered topology
Add: pvmpov running
Application topology is recovered using
normalization and pruning algorithms

12. Dynamic Topology Inference by VTTIF
VNET Daemons on Hosts
Aggregated
Traffic Matrix
VNET Daemon at Proxy
Smoothed Traffic Matrix
2. Low Pass Filter Aggregation
1. Fast updates
3. Threshold change detection
Topology change output

13. Outline Virtual machine grid computing Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET, VTTIF Adaptive virtual network
Evaluation
Summary

14. Adaptation Applications Application performance measure
BSP
Transactional ecommerce
Application performance measure
Application throughput
VTTIF
Network monitoring
Monitoring and inference
Single hop
Worst fit
Optimization metric
Single metric
Combined metric
Adaptation algorithm
Overlay topology
Forwarding rules
VM migration
Adaptation mechanisms

15. Optimization Problem (1/2) Topology Only
Informally stated:
Input
Network traffic load matrix of application
Output
Overlay topology connecting hosts
Forwarding rules on the topology
Such that the application throughput is maximized
The algorithm is described in detail in the paper

16. Illustration of Topology Adaptation in Virtuoso
Fast-path links amongst the VNETs hosting VMs
Resilient Star Backbone
User’s
LAN
Foreign host
LAN 1
VM 1
Host 1 +
VNET
IP network
Proxy +
VNET
Merged matrix as inferred by VTTIF
Foreign host
LAN 2
VM 2
VM 4
VM 3
Host 3 +
VNET
Host 4 +
VNET
Host 2 +
VNET
Foreign host
LAN 4
Foreign host
LAN 3

17. Evaluation Wide-Area testbed Reaction time of VNET
Patterns: A synthetic BSP benchmark
Benefits of adaptation (performance speedup)
Eight VMs on a single cluster, all-all topology
Eight VMs spread over WAN, all-all topology
Wide-Area testbed
DOT Network
CMU
Northwestern
VM 6
Proxy
VM 8
University
of Chicago
VM 5 …
VM 1
VM 7

18. Reaction Time

19. Benefits of Adaptation
Benefits accrued as a function of the number of fast-path links added
Patterns has an all-all topology
Eight VMs are used
All VMs are hosted on the same cluster

20. Benefits of Adaptation
Benefits accrued as a function of the number of fast-path links added
Patterns has an all-all topology
Eight VMs are used
VMs are spread over WAN

21. Optimization Problem (2/2) Topology + Migration
Informally stated:
Input
Network traffic load matrix of application
Topology of the network
Output
Mapping of VMs to hosts
Overlay topology connecting hosts
Forwarding rules on the topology
Such that the application throughput is maximized
The algorithm is described in detail in the paper

22. Evaluation Applications Benefits of adaptation (performance speedup)
Patterns: A synthetic BSP benchmark
TPC-W: Transactional web ecommerce benchmark
Benefits of adaptation (performance speedup)
Adapting to compute/communicate ratio
Adapting to external load imbalance

23. Effect on BSP Application Throughput of Adapting to Compute/Communicate Ratio

24. Effect on BSP Application Throughput of Adapting to External Load Imbalance

25. TPCW Throughput (WIPS) With Image Server Facing External Load
No Topology
Topology
No Migration
1.216
1.76
Migration
1.4
2.52

26. Outline Virtual machine grid computing Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET, VTTIF Adaptive virtual network
Evaluation
Summary

27. Summary
Dynamically adapt unmodified applications on unmodified operating systems in virtual environments to available resources
The adaptation mechanisms are application independent and controlled automatically without user or developer help
Demonstrate the feasibility of adaptation at the level of collection of VMs connected by Virtual Networks
Show that its benefits can be significant for two classes of applications

28. For More Information Future Work Related Talk at HPDC 2005
Free network measurement (Wren) – Collaboration with CS, W&M
Applicability of a single optimization scheme
Related Talk at HPDC 2005
J. Lange, A. Sundararaj, P. Dinda, “Automatic Dynamic Run-time Optical Network Reservations”
Wednesday, July 27, 2:00 P.M.
Please visit
Prescience Lab (Northwestern University)
Virtuoso: Resource Management and Prediction for Distributed Computing using Virtual Machines
VNET is publicly available from above URL