adaptive source routing and speculative execution … · bachelor thesis oliver michel...
TRANSCRIPT
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Bachelor Thesis
Oliver [email protected]
November 2012
Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Outline
Oliver Michel, University of Vienna, 11/30/2012
•Motivation
•Objectives and Measures
•Prototype
•Evaluation
•Conclusions
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Outline
Oliver Michel, University of Vienna, 11/30/2012 2Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Motivation 1
Oliver Michel, University of Vienna, 11/30/2012
• tele-medicine becoming more popular in all medical disciplines and application scenarios
3
[Bergrath et.al. - PLOS ONE 2012]
Monday, February 11, 13
•not widely deployed in pre-hospital medical care due to deficient and constrained mobile connectivity
•design an easy to deploy framework usable for any application to enhance mobile network connectivity
• special needs in health-care scenario
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Motivation 2
Oliver Michel, University of Vienna, 11/30/2012 4Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Objective
Oliver Michel, University of Vienna, 11/30/2012
What to achieve?
5Monday, February 11, 13
•always available
• responsive
• fast
• secure
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Objective
Oliver Michel, University of Vienna, 11/30/2012
What to achieve?
5Monday, February 11, 13
•always available
• responsive
• fast
• secure
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Objective
Oliver Michel, University of Vienna, 11/30/2012
• resilience
•availability
• latency
• throughput
• transparency
What to achieve?
5Monday, February 11, 13
•always available
• responsive
• fast
• secure
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Objective
Oliver Michel, University of Vienna, 11/30/2012
• resilience
•availability
• latency
• throughput
• transparency
•multi-homing
• resource selectionsource-routing
•concurrent multipath transmission
• speculative execution
What to achieve?
5Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Multi-Homing
Oliver Michel, University of Vienna, 11/30/2012 6Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Multi-Homing
Oliver Michel, University of Vienna, 11/30/2012
ISP 1 ISP 2 ISP 3
6Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Multi-Homing
Oliver Michel, University of Vienna, 11/30/2012
ISP 1 ISP 2 ISP 3ISP 1 ISP 2 ISP 3
6Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Multi-Homing
Oliver Michel, University of Vienna, 11/30/2012
ISP 1 ISP 2 ISP 3ISP 1 ISP 2 ISP 3ISP 1 ISP 2 ISP 3
6Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Multi-Homing
Oliver Michel, University of Vienna, 11/30/2012
ISP 1 ISP 2 ISP 3ISP 1 ISP 2 ISP 3ISP 1 ISP 2 ISP 3ISP 1 ISP 2 ISP 3
6Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Resource-Selection
Oliver Michel, University of Vienna, 11/30/2012
ISP 1
ISP 2
ISP 3
7Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Concurrent Multipath Transmission
Oliver Michel, University of Vienna, 11/30/2012
ISP 1
ISP 2
ISP 3
8Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Speculative Execution
Oliver Michel, University of Vienna, 11/30/2012
ISP 1
ISP 2
ISP 3
3
32
21
1
9Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Latency-based Path Selection
Oliver Michel, University of Vienna, 11/30/2012
Lr =
0
BBBB@
��!lr�!...
��!lr�1�!lr
1
CCCCA�!lr = (lr,i, lr,i+1, ..., lr,n)
s(L, µ) = (p0, p1, ..., pµ), µ n
min(��!lr+1) = lr+1,sr(L,µ)
path latencies get collected in sliding window matrix:
selection function s(L, μ) returns “best” μ path indices according to some objective (here min! latency):
path decision was correct if:
10Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Requirements
Oliver Michel, University of Vienna, 11/30/2012
• improve data-transmission between a mobileclient and arbitrary servers
• transparently usable by any application
•executable in user-space
11Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
System Architecture
Oliver Michel, University of Vienna, 11/30/2012
mobile clientwith path-selection agent
ISP 1
ISP 2
ISP 3servergateway
12Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
System Architecture: Client
Oliver Michel, University of Vienna, 11/30/2012
Client
wlan0192.168.60.2/24
wlan1192.168.61.2/24
wlan2192.168.62.2/24
Clienttun010.0.0.1/24
A1
A2
A3
•controls active probing
•performs path-selection
• reads data from tunnel-device
•encapsulates data and sends over selected path
13Monday, February 11, 13
• reads data from public interface
• removes custom header
•writes data to tunnel device for forwarding in kernel and NAT
• (also does active probing on return path)
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
System Architecture: Gateway
Oliver Michel, University of Vienna, 11/30/2012
Gateway
GW tun010.0.0.2/24 FW NAT eth0
192.168.1.5/24eth1
192.168.88.2/24
14Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
System Architecture: Packet Encapsulation
Oliver Michel, University of Vienna, 11/30/2012
ASRTunnelClient ASRTunnelGateway NAT
CPi ➞ GPCT ➞ SCT ➞ S CT ➞ S GP➞ S
GP ➞ CPi S ➞ CTS ➞ CT S ➞ CT S ➞ GP
TunnelDeviceCT
Public InterfaceS
• IP-layer packets get encapsulated as UDP payload for transmission over tunnel
•custom 12 Byte packet header: uint8_t _flags; uint8_t _client_id; uint16_t _pl_length; uint32_t _seqn; uint32_t _client_addr;
15Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
System Architecture: Modules
Oliver Michel, University of Vienna, 11/30/2012
NAT
Public InterfaceGP
DatagramSocketGP
ASRTunnelGateway
TunnelDeviceGT
Public InterfaceSP
Server Application
ASRTunnelClient
PathSelector
SMAPathSelector
TunnelDeviceCT
DatagramSocketCPi
Client
Gateway
Server
Agent
PathSelector
SMAPathSelector
AgentInternet
Internet
Client ApplicationClient
ApplicationClient Application
RoutingRouting
Routing
RoutingRouting
IP Rules
RoutingRouting
IP Tables
16Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Results: Path Selection 1
Oliver Michel, University of Vienna, 11/30/2012
2 4 6 8 10 12 140.0
0.1
0.2
0.3
0.4
0.5
window size
fractionofpathchanges
2 4 6 8 10 12 140.70
0.75
0.80
0.85
0.90
0.95
1.00
window size
fractionofcorrectdecisions
2 4 6 8 10 12 14
80
90
100
110
window size
latency@msD 99th %ile
95th %ile90th %ilemean
• post-hoc analysis of SMA, TPMA, and EWMA algorithms on measured latency data (PlanetLab) and sampled values from Pareto-Type 1 and Gaussian
• for window-based algorithms a window size between 4-6 seems reasonable
17Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Results: Path Selection 2
Oliver Michel, University of Vienna, 11/30/2012
100 150 200 250 300 3500.0010.002
0.0050.010.02
0.050.10.2
0.51
Latency @msD
FractionofpacketslateHlog
.L0 10000 20000 30000 40000 50000
0.0010.002
0.0050.010.02
0.050.10.2
0.51
Latency @msD
FractionofpacketslateHlog
.L
• SMA5 path-selection from data collected from a PL tripartide overlay graph
• SMA surprisingly good, close to optimal (in retrospect)
• TPMA, EWMA slightly inferior
• SMA5 using data-flow (64-128kbit/s) on wireless testbed
• latencies of probe, as well as data traffic (1 per second, exponential)
18Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Results: Fast Adaption and Handover
Oliver Michel, University of Vienna, 11/30/2012
0 100 200 300 4000
1000
2000
3000
4000
5000
6000
7000
Time @sD
Throughput@By
teD
0 20 40 60 80 100 120 1400
20000
40000
60000
80000
100000
Packet
Latency@msD
•measured latency data modified using netem
• satisfying handover-behavior
• little occurrence of packet losses while switching paths
• continuous high data throughput
19Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Results: Packet Replication
Oliver Michel, University of Vienna, 11/30/2012
1e-05
0.0001
0.001
0.01
0.1
1
0 200 400 600 800 1000fr
acti
on o
f pac
kets
late
latency threshold [ms]
1 path2 paths3 paths
• redundant multipath transmission (i.e. packet duplication) may significantly reduce the latency tail
• virtually no packet loss in case of path failure
• general technique for system designers when secondary resources would be idling normally [Vulimiri et. al. - Hotnets ’12]
20Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Future Directions
Oliver Michel, University of Vienna, 11/30/2012
• detailed Investigation of TCP behavior
- TCP connections sometimes get stuck when paths switch frequently
• IP Fragmentation
- iptables NAT functionality does not support fragmented IP packets
• more detailed parameter study for path-selection
- other algorithms (e.g. multi-armed bandit)
• experimentation with different probing intervals
• consideration of further metrics (esp. bandwidth)
21Monday, February 11, 13
ADAPTIVE SOURCE ROUTING AND SPECULATIVE EXECUTION FOR MULTI-HOMED WIRELESS CLIENTS IN PRECLINICAL MEDICAL CARE
Conclusions
Oliver Michel, University of Vienna, 11/30/2012
• transparently usable framework designed to enhance mobile data connectivity
• technically feasible and performant
•modular design allowing system designers to attach custom logic and state
• investigation of reasonable approximations for the Internet path-selection problem
• focus on special needs and applicability in the health-care field (esp. preclinical medical care)
22Monday, February 11, 13