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CHAIR FOR SOFTWARE DESIGN AND QUALITY
OMPCMAn OMNet++ simulator for Palladio
Jorg Henß | November 9, 2012
KIT – University of the State of Baden-Wuerttemberg and
National Laboratory of the Helmholtz Association
www.kit.edu
Yet another Simulation?
Network supportCommunication essential for distributed systems
State of Palladio networking insufficient
No good understanding of network effects
IdeaCreate simple simulation platform
experiment with performance influence of networks
rapid prototyping of new simulation elements
→ use a full fletched network simulation framework!
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 2/17
Yet another Simulation?
Network supportCommunication essential for distributed systems
State of Palladio networking insufficient
No good understanding of network effects
IdeaCreate simple simulation platform
experiment with performance influence of networks
rapid prototyping of new simulation elements
→ use a full fletched network simulation framework!
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 2/17
Yet another Simulation?
Network supportCommunication essential for distributed systems
State of Palladio networking insufficient
No good understanding of network effects
IdeaCreate simple simulation platform
experiment with performance influence of networks
rapid prototyping of new simulation elements
→ use a full fletched network simulation framework!
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 2/17
Yet another Simulation?
Network supportCommunication essential for distributed systems
State of Palladio networking insufficient
No good understanding of network effects
IdeaCreate simple simulation platform
experiment with performance influence of networks
rapid prototyping of new simulation elements
→ use a full fletched network simulation framework!
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 2/17
OMNeT++
OMNeT++implemented in c++
matured network model
many experimental extensions
advanced visualisations
uses textual syntax for model definition
academic license
Good match for palladiomodule/component based
has notion of interfaces and ports
Eclipse based IDE
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 3/17
OMNeT++
OMNeT++implemented in c++
matured network model
many experimental extensions
advanced visualisations
uses textual syntax for model definition
academic license
Good match for palladiomodule/component based
has notion of interfaces and ports
Eclipse based IDE
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 3/17
Simplified Model
ProblemPalladio has high simulation complexity
many modeling elements
simulation semantics “underspecified”
The RISC Ideasimplicity and regularity
used as internal microcode engine
include only those instructions really used
complex instructions mapped to simple ones
→ create SimCore model for Palladio
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 4/17
Simplified Model
ProblemPalladio has high simulation complexity
many modeling elements
simulation semantics “underspecified”
The RISC Ideasimplicity and regularity
used as internal microcode engine
include only those instructions really used
complex instructions mapped to simple ones
→ create SimCore model for Palladio
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 4/17
Examples: Branch
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 5/17
Examples: ExternalCall
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 6/17
Examples: ExternalCall
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 7/17
Simulation Prototype
OMPCM-VariablesStack handling
Evaluation of stochastic expressions (StoEx-C)
OMPCM-CoreDynamic behavior (ExtQueueing)
Represents SimCore
OMPCM-NetNetwork bindings
OMNeT++Provides static structure
Textual syntax & IDE
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 8/17
OMPCM-Net
OMPCM network elementscomponent proxy
proxy client
app server
call handler
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 9/17
Workflow
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 10/17
Transformation
Translation of Palladio models to OMNeT++OMNeT++ based on a grammar
derive metamodel using XText
M2T transformation for free
SimCore TransformationQVT-O M2M transformation
∼ 2800 Lines of Code
modular designed: with and w/o full network model
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 11/17
Result Importer
Support OMNeT++ SCAVE format (experimental)visualise results using SensorFramework
compare runs e.g. to SimuCom
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 12/17
Some Results
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 13/17
Some Results cont’d
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 14/17
Simulation Performance
Simulation timeSimuCom 7.38s
OMPCM (no net): 6.29s
OMPCM (net): 24m 55s
Generated eventsOMPCM (no net): 124272
OMPCM (net): 96374348
Memory footprintSimuCom: ???
OMPCM: ∼80 MB
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 15/17
Evolved Questions
connection strategiespoolingconnection per requestconnection per call
how handle limited socketstoo realistic?
how model different kinds of clientsclient communication even relevant for us?modeling the internet delay spacepossible solution: Lookup table for network setup
replication of server nodesload balancingcontent switching
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 16/17
Conclusion
InsightsOMNeT++ is versatile
detailed network simulation is expensive
many aspects of networking still unclear in Palladio
Roadmapautomate transformation using WFE
validate implementation→ call for case studies
create a simple native network scheduler for Palladio
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 17/17
Experiments
Client communicationCentral client populationDistributed client populationNo client communication
Influence of bandwidth10Mbps vs. 100Mbps
Removal of network layersRaw TCP communication
Influence of packet errors/reliabilityCurrently not working
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 18/17
First results - 10 vs. 100Mbps
0 50 100
0.0
0.2
0.4
0.6
0.8
1.0
Workload duration
Seconds
StandardCombinedRawNo Network
0 20 40 60 80 1000.0
0.2
0.4
0.6
0.8
1.0
Workload duration
Seconds
StandardCombinedRawNo Network
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 19/17
First results(2)
0 20 40 60 80 100 120
0.00
0.05
0.10
0.15
0.20
0.25
0.30
No NetworkStandard
0 20 40 60 80 100 1200.00
0.05
0.10
0.15
0.20
0.25
RawCombined
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 20/17
First results(3)
Scenario No Net Full Net Combined CU w/o SW RAW10Mbps
Time 00:00:03 00:06:14 00:05:12 - 00:01:45Requests 1002 311 318 - 357
100Mbps
Time 00:00:03 00:12:49 00:18:34 00:14:13 00:04:52Request 1002 585 996 1000 1008
Table : Simulation times and throughput
Motivation Principles State of Development Evaluation Conclusion
Jorg Henß – OMPCM November 9, 2012 21/17
