Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of...
-
Upload
caroline-harriet-morris -
Category
Documents
-
view
215 -
download
2
Transcript of Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of...
![Page 1: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/1.jpg)
Suzhen Lin, A. Sai Sudhir, G. Manimaran
Real-time Computing & Networking LaboratoryDepartment of Electrical and Computer
EngineeringIowa State University, USA
http://www.ee.iastate.edu/~gmani
ConFiRM-DRTS: A Certification Framework for
Dynamic Resource Management in Distributed Real-Time Systems
![Page 2: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/2.jpg)
2
Outline
Problem statement Model and certification requirements The proposed certification framework Case study of feedback-based
scheduling verification Conclusions
![Page 3: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/3.jpg)
3
Real-time Systems
Logical correctness & timeliness
Real-time tasks have deadlines
Real-time tasks:periodic and aperiodic
![Page 4: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/4.jpg)
4
System Model
Heterogeneous computing nodes Arbitrary network topology Periodic and aperiodic workloads
Local scheduler Global scheduler (load balancer) Packet scheduler
![Page 5: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/5.jpg)
5
Problem Statement
Problem overview Certification of dynamic RM
Technical considerations Virtual homogeneity Performance Stability Verifiability
![Page 6: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/6.jpg)
6
Two Views to Certifiability
How to Certify a given system Testing, verification, validation
Design for Certifiability Employ provable techniques and tools
![Page 7: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/7.jpg)
7
DRE Certification Requirements and Certification Techniques/Tools
Requirements Techniques/Tools
R1: Traditional functional and performance testing
Test decompostion, observability, reproducibility, environment simulation and representativity
R2: Testing of the dynamic resource allocation
Petri nets based verification and simulation
R3: Virtual homogeneity Middleware (e.g., CORBA)
R4: Verification of Schedulability
Feedback control scheduling and simulation
R5: Verification of Stability
Feedback control theory and simulation
![Page 8: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/8.jpg)
8
DRE Certification Test-bed
![Page 9: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/9.jpg)
9
Traditional Functional and Performance Testing
Organization Organize testing into distinct test phases
Observability Observe the correctness of system behavior
Reproducibility Get the same results when the program is
executed
![Page 10: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/10.jpg)
10
Traditional Functional and Performance Testing ...
Environment Simulation It mimics the system behavior through test
runs
Representativity System should be represented by realistic
inputs
Petri Nets for Verification of RT Systems Reachability analysis.
![Page 11: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/11.jpg)
11
Virtual Homogeneity Using RTCORBA
Each RT-CORBA invocation has a priority. RT Portable Object Adaptor(RT POA) for demultiplexing object requests to the appropriate object skeleton.
![Page 12: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/12.jpg)
12
Fault Injection Testing Injecting software faults at compile-time Injecting software faults at run-time
Interface Mutation Testing Involves testing interactions between various
units. Testing Through Equivalent Configurations
Involves allowing configurations that are equivalent to those already tested.
Certification Techniques on an Object-based Middleware System
![Page 13: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/13.jpg)
13
A Distributed Object Monitoring and Testing System
![Page 14: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/14.jpg)
14
Design Methodology for Verifiability of Feedback Control Scheduling
System Modeling Controller Design Model Verification Scheduler Design Experimental Evaluation
![Page 15: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/15.jpg)
15
Two-loop Feedback Scheduling
PID Controllers are Used
![Page 16: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/16.jpg)
16
Performances for Control Systems
Overshoot Settling time Steady-state
error
M
st
eM
ste
![Page 17: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/17.jpg)
17
Performances for Scheduling Systems
taskssubmittedof
tasksadmittedofGRRatioGuarantee
#
#)(
GR1)RR(RatioectionRej
tasksadmitted#
deadlinestheirmeetthattasks#)HR(RatioHit
HR1)MR(RatioMiss
GRHRtaskssubmitted#
deadlinestheirmeetthattasks#)ER(RatioEffective
Goal: to improve ER.
![Page 18: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/18.jpg)
18
Case study—Task Model Aperiodic soft RT task: Estimated Execution Time:
),,,,( iiiiii dBCETWCETraT
)( iiii BCETAvECTetfAvCETEET
ii TofTimeExecutionCaseWorstWCET
ii TofTimeExecutionCaseBestBCET
ii TofTimeExecutionCaseAverageAvCET
![Page 19: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/19.jpg)
19
Case Study—Local Scheduling Systems
Set point: desired MR & RR
Regulated/Measured variable: MR & RR
Control variable: Estimated execution time
Actuator: Execution time estimator
Controller: PI
![Page 20: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/20.jpg)
20
Case Study — Local Scheduling system
![Page 21: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/21.jpg)
21
Stability Analysis for Local System
From Control theory, we get the characteristic equation for the local system in Z domain:
The eigen values of the equation are:
Since , all the eigen values lie within the unit circle, so the local system is stable.
0
11
1
111
//
//
rgfKnfz
zrgfKnf
z
z
mgfKnfz
zmgfKnf
z
z
rmmrmrrm
rmmrmrrm
rgfKnfz
mgfKnfzz
rmmrmrrm
/4
/32,1 1
1,
1
1,0
00 // rgfKnfandmgfKnf rmmrmrrm
![Page 22: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/22.jpg)
22
Case Study—Global scheduling system
The inner loop responds to changes much more quickly than the outer loop.
So we can treat the local system as a model that has transfer function I (identity matrix).
The analysis of the global system is similar to the local system.
![Page 23: Suzhen Lin, A. Sai Sudhir, G. Manimaran Real-time Computing & Networking Laboratory Department of Electrical and Computer Engineering Iowa State University,](https://reader035.fdocuments.us/reader035/viewer/2022062719/56649ef15503460f94c032a7/html5/thumbnails/23.jpg)
23
Conclusion Certifying dynamic RM
Very complex process 100% verification may not be achievable
How to certify a given system Traditional testing, Validation Middleware design methodology
Design for Certifiability Employ mathematically provable techniques E.g., Feedback control scheduling, Petri nets