Abstract
The equal slack (EQS) priority assignment method has shown promising results with distributed real-time systems. As a result, the EQS is considered the first choice for distributed real-time database systems (DRTDBS). However, the integration of EQS with the DRTDBS comes at cost of many issues—intensive data contention due to dynamic cohort priority assignment, global deadlock, and wastage of resources due to cyclic restart. To address the above problems, this paper proposes a contention aware equal slack (CA-EQS) priority assignment heuristic. The CA-EQS heuristic reduces the data contention by utilizing the size of the cohort dependency. After the execution of the first cohort, the information about its size of dependency will be piggybacked with the message that initiates the execution of immediately next cohort of a parent transaction at some other site. The reason for going with the piggybacking approach is that the dependency size of the currently executing cohort not only depends on the data items locked by it but also on the data items that are locked by the cohorts that have already completed their execution before it. This way, a true data contention level can be assessed without any extra overhead (message and time). The CA-EQS solves the problem of deadlock and cyclic restart. Results from the simulation tool validate up to 9% drop in transactions miss ratio and up to 16% reduction in a number of transactions’ rollbacks by the CA-EQS heuristic over EQS, EQF, number of locks (NL), and most dependent transactions first (MDTF).
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References
Pandey S, Shanker U (2020) Transaction scheduling protocols for controlling priority inversion: a review. Comput Sci Rev 35:100215
Pandey S, Shanker U (2016) Transaction execution in distributed real-time database systems. In: Proceedings of the International Conference on Innovations in information Embedded and Communication Systems, pp 96–100
Pandey S, Shanker U (2017) On using priority inheritance based distributed static two phase locking protocol. In: Proceedings of the International Conference on Data and Information System (ICDIS), pp 179–188
Bernstein P, Hadzilacos V, Goodman N (1987) Concurrency control and recovery in database systems. Addison-wesley, Reading
Pandey S, Shanker U (2018) Priority inversion in DRTDBS: challenges and resolutions. In: Proceedings of the ACM India Joint International Conference on Data Science and Management of Data (CoDS-COMAD ‘18), pp 305–309
Lam K, Pang CL, Son S, Cao J (1999) Resolving executing-committing conflicts in distributed real-time database systems. Comput J 42(08):674–692
Lam KY (1994) Concurrency control in distributed real time database systems, PhD Thesis
Abbott RK, Molina HG (1992) Scheduling real-time transactions: a performance evaluation. ACM Trans Database Syst 17(03):513–560
Haritsa JR, Carey MJ, Livny M (1992) Data access scheduling in firm real-time database systems. Real-Time Syst 04(03):203–241
Shanker U, Misra M, Sarje AK (2008) Distributed real time database systems: background and literature review. Int J Distrib Parallel Databases 23(02):127–149
Lee V, Lam K, Kao B (1999) Priority scheduling of transactions in distributed real-time databases. Real-Time Syst 16(1):31–62
Liu CL, Layland JW (1973) Scheduling algorithms for multiprogramming in a hard-real-time environment. J ACM (JACM) 20(1):46–61
Pang H, Livny M, Carey MJ (1992) Transaction scheduling in multiclass real-time database systems. In: Proceedings of IEEE Real-Time Systems Symposium (RTSS), pp 23–34
Datta A, Mukherjee S, Konana P, Viguier I, Bajaj A (1996) Multiclass transaction scheduling and overload management in firm real-time database systems. Inf Syst 21(1):29–54
Kao B, Garcia-Molina H (1997) Deadline assignment in a distributed soft real-time system. IEEE Trans Parallel Distrib Syst 8(12):1268–1274
Stankovic J, Ramamritham K, Towsley D (1991) Scheduling in real-time transaction systems. In: Foundations of real-time computing: scheduling and resource management, pp 157–184
Shanker U, Misra M, Sarje AK (2006) SWIFT—a new real time commit protocol. Distrib Parallel Databases 20(01):29–56
Lee VCS, Lam KW, Hung SL (2002) Concurrency control for mixed transactions in real-time databases. IEEE Trans Comput 51(07):821–834
Ulusoy O (1995) A study of two transaction-processing architectures for distributed real-time data base systems. J Syst Softw 31(02):97–108
Bestavros A, Lin K, Son S (2012) Real-time database systems: issues and applications, vol 396. Springer, New York
Davis RI, Cucu-Grosjean L, Bertogna M, Burns A (2016) A review of priority assignment in real-time systems. J Syst Architect 65:64–82
Audsley NC (2001) On priority assignment in fixed priority scheduling. Inform Process Lett 79(1):39–44
Audsley NC (1991) Optimal priority assignment and feasibility of static priority tasks with arbitrary start times. Technical Report YCS164, Real- Time Systems Research Group, Department of Computer Science, University of York, UK
Begam R, Xia Q, Zhu D, Aydin H (2016) Preference-oriented fixed-priority scheduling for periodic real-time tasks. J Syst Architect 69:1–14
Zhao Y, Zeng H (2018) The concept of unschedulability core for optimizing real-time systems with fixed-priority scheduling. IEEE Trans Comput 68(6):926–938
Zhao Y, Zeng H (2019) The concept of maximal unschedulable deadline assignment for optimization in fixed-priority scheduled real-time systems. Real-Time Syst 55(3):667–707
Davis R, Bertogna M, Bonifaci V (2016) On the compatibility of exact schedulability tests for global fixed priority pre-emptive scheduling with Audsley’s optimal priority assignment algorithm. Real-Time Syst 52:113–122
Chishiro H, Takeda A, Funaoka K, Yamasaki N (2010) Semi-fixed-priority scheduling: new priority assignment policy for practical imprecise computation. In: IEEE 16th International Conference on Embedded and Real-Time Computing Systems and Applications
Lee J, Chwa HS, Lee J, Shin I (2016) Thread-level priority assignment in global multiprocessor scheduling for DAG tasks. J Syst Softw 113:246–256
He Q, Guan N, Guo Z (2019) Intra-task priority assignment in real-time scheduling of dag tasks on multi-cores. IEEE Trans Parallel Distrib Syst 30(10):2283–2295
Maxim D, Buffet O, Santinelli L, Cucu-Grosjean L, Davis RI (2011) Optimal priority assignment algorithms for probabilistic real-time systems. In: RTNS, pp 129–138
Peng B, Fisher N, Chantem T (2016) MILP-based deadline assignment for end-to-end flows in distributed real-time systems. In: The 24th International Conference on Real-Time Networks and Systems
Haritsa JR, Ramamritham K, Gupta R (2000) The PROMPT real-time commit protocol. IEEE Trans Parallel Distrib Syst 11(02):160–181
Haritsa JR, Livny M, Carey MJ (1991) Earliest deadline scheduling for real-time database systems. In: Twelfth, Real-Time Systems Symposium, Proceedings. IEEE, pp 232–242
Haritsa JR, Livny M, Carey MJ (1991) Earliest deadline scheduling for real-time database systems. Madison, WI
Lee VC, Lam KY, Kao B, Lam KW, Hung SL (1996) Priority assignment for sub-transaction in distributed real-time databases. In: RTDB
Lee VV, Lam KY, Hung SL (1995) Virtual deadline assignment in distributed real-time database systems. In: Proceedings Second International Workshop on Real-Time Computing Systems and Applications. IEEE
Pandey S, Shanker U (2018) IDRC: a distributed real-time commit protocol. Proc Comput Sci 125:290–296
Pandey S, Shanker U (2018) A one phase priority inheritance commit protocol. In: Proceedings of the 14th International Conference on Distributed Computing and Information Technology (ICDCIT) Bhubaneshwar, India
Pandey S, Shanker U (2018) CART: a real-time concurrency control protocol. In: Desai BC, Hong J, McClatchey R (eds) 22nd International Database Engineering and Applications Symposium (IDEAS 2018). ACM, New York
Pandey S, Shanker U (2020) Race: a concurrency control protocol for time–constrained transactions. Arab J Sci Eng 45(12):10131–10146
Yu PS, Wu K-L, Lin K-J, Son SH (1994) On real-time databases: concurrency control and scheduling. Proc IEEE 82(01):140–157
Chen HR, Chin YH (2003) An adaptive scheduler for distributed real-time database systems. Inf Sci 153:55–83
Agrawal S, Shanker U, Singh A, Anand A (2010) SPEEDITY—a real time commit protocol. Int J Comput Appl 1(3):86–93
Shanker U, Vidyareddi B, Shukla A (2012) PERDURABLE: A Real Time Commit Protocol. In: Özyer T, Kianmehr K, Tan M. (eds) Recent Trends in Information Reuse and Integration. Springer, Vienna, pp 1–17
Shanker U, Misra M, Sarje AK (2005) Priority assignment heuristic to cohorts executing in parallel. In: 9th International Conference on World Scientific and Engineering Academy and Society (WSEAS)
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The CSIR, India is acknowledged for providing financial support [Grant No 1061461137].
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Pandey, S., Shanker, U. A contention aware EQS priority assignment heuristic for cohorts in DRTDBS. J Supercomput 77, 6629–6663 (2021). https://doi.org/10.1007/s11227-020-03530-5
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DOI: https://doi.org/10.1007/s11227-020-03530-5