Transcript VNET - Computer Science Division

Towards Virtual Networks for Virtual
Machine Grid Computing
Ananth I. Sundararaj
Peter A. Dinda
Prescience Lab
Department of Computer Science
Northwestern University
http://virtuoso.cs.northwestern.edu
Outline
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Virtual machine grid computing
Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET
Adaptive virtual network
Related Work
Conclusions
Current Status
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arbitrary amounts of
AimDeliver
computational power to perform
distributed and parallel computations
Traditional
Paradigm
New
Paradigm
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Resource multiplexing using
Grid OS level mechanism
Computing
3b
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Grid Computing
using virtual
machines
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3a
6a
Problem1:
6b
Complexity from resource
Solution
user’s perspective
Problem2:
Complexity from resource
owner’s perspective
Virtual Machines
What are they?
How to leverage
them?
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Virtual Machines
Virtual machine monitors (VMMs)
•Raw machine is the abstraction
•VM represented by a single
image
•VMware GSX Server
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Virtual machine grid computing
• Approach: Lower level of abstraction
– Raw machines, not processes, jobs, RPC calls
R. Figueiredo, P. Dinda, J. Fortes, A Case For Grid
Computing on Virtual Machines, ICDCS 2003
• Mechanism: Virtual machine monitors
• Our Focus: Middleware support to hide complexity
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Ordering, instantiation, migration of machines
Virtual networking
remote devices
Connectivity to remote files, machines
Information services
Monitoring and prediction
Resource control
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The Simplified Virtuoso Model
User’s
LAN
Virtual networking ties the
machine back to user’s
home network
Orders a raw
machine
VM
Specific hardware and
performance
Basic software
installation available
Virtuoso continuously monitors and adapts
User
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User’s View in Virtuoso Model
User’s
LAN
VM
User
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Outline
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Virtual machine grid computing
Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET
Adaptive virtual network
Related Work
Conclusions
Current Status
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Why VNET? A Scenario
Foreign hostile
LAN
User’s friendly
LAN
IP network
User has just bought
Virtual Machine
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Why VNET? A Scenario
VM traffic going
out on foreign
LAN
Foreign hostile
LAN
User’s friendly
LAN
X
IP network
Host
Proxy
Virtual Machine
A machine is suddenly plugged into a foreign
network. What happens?
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Does it get an IP address?
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Is it a routeable address?
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Does firewall let its traffic
through? To any port?
VNET: A bridge with long wires
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Outline
•
•
•
•
•
•
•
•
Virtual machine grid computing
Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET
Adaptive virtual network
Related Work
Conclusions
Current Status
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A Layer 2 Virtual Network for the
User’s Virtual Machines
• Why Layer 2?
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Protocol agnostic
Mobility
Simple to understand
Ubiquity of Ethernet on end-systems
• What about scaling?
– Number of VMs limited (~1024 per user)
– One VNET per user
– Hierarchical routing possible because MAC
addresses can be assigned hierarchically
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VNET operation
“eth0”
ethx
Client
LAN
Client
VNET
Proxy
Ethernet Packet
Captured by
Promiscuous
Packet Filter
ethy
“Host
Only”
Network
VM
“eth0”
vmnet0
ethz
IP Network
VNET
Host
Ethernet Packet Tunneled
over TCP/SSL Connection
Ethernet
Packet
Injected
Directly
into VM
interface
Traffic outbound from the user’s LAN
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Performance Evaluation
However
Main goal
VNET’s performance should be
Convey the network management
problem induced by VMs to the
home network of the user
• In line with physical network
Metrics
Latency
Why?
How?
• Comparable to other options
• Sufficient for scenarios
Bandwidth
Why?
How?
• small transfer
• ping
• Large transfer
• ttcp
• Interactivity
• hour long intervals
• low throughput
• socket buffer
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• 1 GB of data
VNET test configuration
100 mbit
Switches
Client
100 mbit
Switch
100 mbit
Switch
Router
Router
Firewall 1
Proxy
VM
Host
Local
IP Network
(14 hops via Abilene)
Carnegie Mellon University, PA
Northwestern University, IL
Wide area configuration
Client
100 mbit
100 mbit
Switches Firewall Switch
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Router
100 mbit
Switch
Firewall
2
Proxy
VM
100 mbit
Switches
Host
Local
Local area configuration
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Average latency over WAN
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Host - VM
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30
Milliseconds
Proxy - Host
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Client - Proxy
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0
Client<->VM
Client<->VM (VNET)
Client<->VM (VNET+SSL)
(Physical Network)
VM
Host
Client
Proxy
Northwestern University, IL
IP Network
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Carnegie Mellon University, PA
Standard deviation of latency over
WAN
What: VNET increases
variability in latency
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Why: TCP connection
between VNET servers
trades packet loss for
increased delay
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Milliseconds
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40
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Client<->VM
(Physical Network)
Client<->VM (VNET)
Client<->VM (VNET+SSL)
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Bandwidth over WAN
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Expectation:
1.8
VNET to achieve
throughput comparable
to the physical network
MB/s
1.6
1.4
What do we see:
1.2
VNET achieves lower
than expected
throughput
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Why:
0.8
VNET’s is tricking
TTCP’s TCP connection
0.6
0.4
0.2
0
Host<->Client
Client<->VM (VNET)
Client<->VM (VNET+SSL)
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Outline
•
•
•
•
•
•
•
•
Virtual machine grid computing
Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET
Adaptive virtual network
Related Work
Conclusions
Current Status
19
VNET Overlay
Foreign hostile
LAN 1
User’s friendly
LAN
VM 1
Host 1
+
VNET
IP network
Proxy
+
VNET
VM 4
Foreign hostile
LAN 4
Foreign hostile
LAN 2
Host 4
+
VNET
VM 3
Host 3
+
VNET
Foreign hostile
LAN 3
VM 2
Host 2
+
20 VNET
Bootstrapping the Virtual Network
VM
VM
Vnetd
Host +
VNETd
Proxy +
VNETd
• Star topology always possible
VM
• Topology may change
• Links can be added or removed on demand
• Virtual machines can migrate
• Forwarding rules can change
• Forwarding rules can be added or removed on
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demand
Application communication
topology and traffic load;
application processor load
Vnetd layer can collect all
this information as a side
effect of packet transfers
and invisibly act
• VM migrates
VM
Layer
VNETd
Layer
• Topology changes
• Routing change
• Reservation
Network bandwidth and
latency; sometimes
topology
Physical
Layer
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Outline
•
•
•
•
•
•
•
•
Virtual machine grid computing
Virtuoso system
Networking challenges in Virtuoso
Enter VNET
VNET
Adaptive virtual network
Related Work
Conclusions
Current Status
23
Related Work
• Collective / Capsule Computing (Stanford)
– VMM, Migration/caching, Hierarchical image files
• Denali (U. Washington)
– Highly scalable VMMs (1000s of VMMs per node)
• SODA and VIOLIN (Purdue)
– Virtual Server, fast deployment of services
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VPN
Virtual LANs, IEEE
Overlay Networks: RON, Spawning networks, Overcast
Ensim
Virtuozzo (SWSoft)
– Ensim competitor
• Available VMMs: IBM’s VM, VMWare, Virtual
PC/Server, Plex/86, SIMICS, Hypervisor, VM/386
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Conclusions
• There exists a strong case for grid computing
using virtual machines
• Challenging network management problem
induced by VMs in the grid environment
• Described and evaluated a tool, VNET, that
solves this problem
• Discussed the opportunities, the combination
of VNET and VMs present, to exploit an
adaptive overlay network
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Current Status
• Application traffic load measurement
and topology inference [Ashish Gupta]
• Support for arbitrary topologies and
forwarding rules
• Dynamic adaptation to improve
performance
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Pseudo
proxy
Current Status Snapshots
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• For More Information
– Prescience Lab (Northwestern University)
• http://plab.cs.northwestern.edu
– Virtuoso: Resource Management and
Prediction for Distributed Computing using
Virtual Machines
• http://virtuoso.cs.northwestern.edu
• VNET is publicly available from
• http://virtuoso.cs.northwestern.edu
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