Designing Distributed Real-Time Systems with Decomposition of End-to-End Timing Donstraints

양극단 지연시간의 분할을 이용한 분산 실시간 시스템의 설계

  • 홍성수 (서울대학교 공과대학 전기공학부)
  • Published : 1997.10.01

Abstract

In this paper, we present a resource conscious approach to designing distributed real-time systems as an extension of our original approach [8][9] which was limited to single processor systems. Starting from a given task graph and a set of end-to-end constraints, we automatically generate task attributes (e.g., periods and deadlines) such that (i) the task set is schedulable, and (ii) the end-to-end timing constraints are satisfied. The method works by first transforming the end-to-end timing constraints into a set of intermediate constraints on task attributes, and then solving the intermediate constraints. The complexity of constraint solving is tackled by reducing the problem into relatively tractable parts, and then solving each sub-problem using heuristics to enhance schedulability. In this paper, we build on our single processor solution and show how it can be extended for distributed systems. The extension to distributed systems reveals many interesting sub-problems, solutions to which are presented in this paper. The main challenges arise from end-to-end propagation delay constraints, and therefore this paper focuses on our solutions for such constraints. We begin with extending our communication scheme to provide tight delay bounds across a network, while hiding the low-level details of network communication. We also develop an algorithm to decompose end-to-end bounds into local bounds on each processor of making extensive use of relative load on each processor. This results in significant decoupling of constraints on each processor, without losing its capability to find a schedulable solution. Finally, we show, how each of these parts fit into our overall methodology, using our previous results for single processor systems.

References

  1. Technical Report YCS 203 Data consistency in hard real-time systems N. Audsley;A. Burns;M. Richardson;A. Wellings
  2. Proceedings of IEEE Conference on Distributed Computing Systems End-to-end scheduling to meet deadlines in distributed systems R. Bettati;J. W.-S. Liu
  3. Principles of Real-Time Systems Preemptive proiority based scheduling: An appropriate engineering approach A. Burns;S. Son(ed.)
  4. Proceedings of IEEE Real-Time Systems Symposium Optimal synchronous capacity allocation for hard real-time communicatins with the timed token protocol B. Chen;G. Agrawal;W. Zhao
  5. Journal of Combinatorial Theory (A) v.14 Fourier-Motzkin elimination and its dual G. Danzig;B. Eaves
  6. IEEE Journal on Selected Areas in Communications v.8 no.3 Scheme for real-time channel establishment in wide-area networks D. Ferrai;D. C. Verma
  7. Proceedings of IEEE Workshop on Parallel and Distributed Real-Time Systems Optimized priority assignment for tasks and messages in distributed hard real-time system J. Garcia;M. G. Harbour
  8. Proceedings of IEEE Real-Time Systems Symposium Guaranteeing end-to-end timing constraints by calibrating intermediate processes R. Gerber;S. Hong;M. Saksena
  9. IEEE Transactions on Softpware Engineering v.21 no.7 Guaranteeing real-time requirements with resourcebased calibration of periodic processes R. Gerber;S. Hong;M. Saksena
  10. Communication of the ACM v.8 no.2 A software design method for real-time systems H. Gomaa
  11. Technical report An end-to-end approach to scheduling periodic tasks with shared resources in multiprocessor systems J. Sun;J. Liu;R. Bettati
  12. Proceedings of IEEE Conference on Distributed Computing Systems Real-Time communication in multi-hop networks D. D. Kandlur;K. G. Shin;D. Ferrari
  13. Proceedings of IEEE Real-Time Systems Symposium The rate monotonic scheduling algorithm: Exact characterization and average case behavior J. Lehoczky;L. Sha;Y. Ding
  14. Journal of the ACM v.20 no.1 Scheduling algorithm for multiprogramming in a hard real-time environment C. Liu;J. Layland
  15. Proceedings of IEEE Real-Time Systems Symposium A Bandwidth allocation scheme for time constrained message transmission on a slotted ring LAN S. Mukherjee;D. Saha;M. Saksena;S. K. Tripathi
  16. Proceedings of IEEE Real-Time Systems Symposium Dynamic end-to-end guarantees in distributed real-time systems M. Di Natale;J. Stankovic
  17. Proceedings of the IEEE v.82 no.1 Scheduling algorithms and operating systems support for of real-time systems K. Ramamritham;J. A. Stankovic
  18. Proceedings of IEEE Infocomm On Guaranteed Delivery of Time-Critical Messages in DQDB D. Saha;M. Saksena;S. Mukherjee;S. K. Tripathi
  19. IEEE Computer v.26 no.9 A systematic approach to designing distributed real-time systems L. Sha;S. S. Sathaye
  20. The Journal of Real-Time Systems v.6 no.2 An extendible approach for analysing fixed priority hard real-time tasks K. Tindell;A. Burns;A. Wellings
  21. Proceedings of IEEE Real-Time Systems Symposium Analysing real-time communications: Controller area network (can) K. Tindell;H. Hansson;A. Wellings
  22. Technical Report RTSRG/91/107 Guaranteeing hard real-time end-to-end communications deadlines K. W. Tindell;A. Burns;A. J. Wellings
  23. IEEE Transactions on Control Systems Technologies v.3 no.2 Scheduling algorithm of data sampling times in the integrated communcation and control systems S. H. Hong