Cloud computing provides on demand accessibility of resources with transparency.The cloud composed of serveral datacenters and customers may acess the computational resources over a network provisioned by cloud service provider. The challenge in cloud environment is to meeting customers demand succesfully by allocating of computational resources.Scheduling is an important criteria that effects performance of systems.Round robin is a preemptive scheduling policy that effects the performance of systems as it provides fairness in scheduling tasks in cloud environment.The current work is based on the time varying time quatum strategy that deals with maximum cpu utilization and minimizes the waiting time,Tunraronud time,Average turn around time ,context switching and provides better performance.

Round robin,scheduling,time quantum,cloud computing

[1] Ahmed Alsheikhyl, Reda Ammar1, Raafat Elfouly , “An Improved Dynamic Round Robin Scheduling Algorithm Based on a Variant Quantum Time” , IEEE 2015.
[2] Jayanti Khatri, “An Improved Dynamic Round Robin CPU Scheduling Algorithm Based on Variant Time Quantum” ,IOSR Journal of Computer Engineering (IOSR-JCE) e-ISSN: 2278-0661,p-ISSN: 2278-8727, Volume 18, Issue 6, Ver. IV (Nov.-Dec. 2016), PP 35-40.
[3] Mohd Abdul Ahad , “ Modifying Round Robin Algorithm for Process Scheduling using Dynamic Quantum Precision “ ,Special Issue of International Journal of Computer Applications (0975 – 8887) on Issues and Challenges in Networking, Intelligence and Computing Technologies – ICNICT 2012, November 2012.
[4] Raman , Dr.Pardeep Kumar Mittal, “An Efficient Dynamic Round Robin CPU Scheduling Algorithm” , International Journal of Advanced Research in Computer Science and Software Engineering , Volume 4, Issue 5, May 2014 .
[5] Muhammad Umar Farooq, Aamna Shakoor, Abu Bakar Siddique , “An Efficient Dynamic Round Robin Algorithm for CPU scheduling”, International Conference on Communication, Computing and Digital System ,2017
[6] Prof. Dipali V. Patel , “A Best Possible Time Quantum for Advanced Round Robin With Shortest Job First Scheduling Algorithm”, IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 03, 2015
[7] P.Surendra Varma , “A Finest Time quantum for improving shortest remaining burst round robin (srbrr) algorithm” , Journal of Global Research in Computer Science, Volume 4, No. 3, March 2013.
[8] Priyanka Sangwan, Manmohan Sharma, Anil Kumar, “Improved Round Robin Scheduling in Cloud Computing” , Advances in Computational Sciences and Technology ISSN 0973-6107 Volume 10, Number 4 (2017) pp. 639-644 © Research India Publications http://www.ripublication.com .
[9] Manish kumar Mishra, “Improved Round Robin CPU Scheduling Algorithm”, Journal of Global Research in computer science, ISSN - 2229-371X, vol. 3,No. 6, June 2012.
[10] Rami J Matarneh, “Self- Adjustment Time Quantum in Round Robin Algorithms Depending on Burst Time of the Now Running Processes”, American Journal of Applied Sciences, ISSN 1546-92396, (10):1831-1837, 2009 .
[11] Saroj Hiranwal, “ Adaptive Round Robin Scheduling using shortest Burst Approach Based on smart time slice ”, International Journal of Data Engineering(IJDE), volume2, Issue 3,2 011 .
[12] H.S. Behera, “Weighted Mean Priority Based scheduling for Interactive systems”, Journal of global Research in computer science, ISSN-2229-371X, volume 2, No.5, May 2011 .
[13] Lalit Kishor & Dinesh Goyal, “Time Quantum Based Improved Scheduling Algorithms”, International Journal of Advanced Research in Computer science and Software Engineering, ISSN: 2277-128X, Volume 3, Issue 4, April 2013 .
[14] H.S.Behera, “ Enhancing the CPU performance using a modified mean-deviation round robin scheduling algorithm for real time systems”, Journal of global Research in computer science, ISSN-2229-371X, volume 3,No. 3, March 2012,
[15] Aashna Bisht, “ Enhanced Round Robin Algorithm for process scheduling using varying quantum precision”, IRAJ International Conference-proceedings of ICRIEST- AICEEMCS,29 th Dec 2013,pune India. ISBN: 978- 93-82702-50-4
[16] Rakash Mohanty & Manas Das, “ Design and performance Evaluation of A new proposed fittest Job First Dynamic Round Robin Scheduling Algorithms”, International journal of computer information systems, ISSN: 2229-5208, vol. 2, No. 2, Feb 2011. [
[17] Debashree Nayak& Sanjeev Kumar Malla, “ Improved Round Robin Scheduling using Dynamic time quantum”, International Journal of computer Applications, volume 38, No. 5, January 2012 Shyam et al., International Journal of Advanced Research in Computer Science and Software Engineering 4(7), July – 2014.
[18] Ishwari Singh Rajput,Deepa Gupta, “A Priority based round robin CPU Scheduling Algorithms for real time systems”, International journal of Innovations in Engineering and Technology, ISSN:2319-1058, Vol. 1 ISSUE 3 ,Oct 2012.
[19] H.S. Behera & Brajendra Kumar Swain, “ A New proposed precedence based Round Robin with dynamic time quantum Scheduling algorithm for soft real time systems”, International Journal of advanced Research in computer science and software Engineering, ISSN:2277- 128X, Vol. 2, ISSUE 6, June 2012.
[20] Brajendra Kumar Swain,H.S Behera and Anmol Kumar Parida, “A new proposed round robin with highest response ratio next scheduling algorithm for soft real time system”, International Journal of Engineering and Advanced Technology, ISSN: 2249-8958, Vol. - 1,ISSUE-3, Feb 2012 .
[21] Taskeen Zaidi, and Rampratap, “Modeling for Fault Tolerance in Cloud Computing Environment.”
Journal of Computer Sciences and Applications, vol. 4, no. 1 (2016): 9-13. doi: 10.12691/jcsa-4-1-2
[22] Abbas Noon, Ali Kalakech and Seifedine Kadry, “ A new Round Robin based scheduling algorithm for operating system: Dynamic quantum using the mean average”, International Journal of computer science, ISSN: 1694-0814, Vol. 8,ISSUE 3, No. 1, May 2011
[23] Rakesh kumar Yadav, Abhishck K Mishra ,Navin Prakash and Himanshu Sharma, “ An Improved round robin scheduling algorithm for CPU scheduling”, International Journal of computer science and Engineering, ISSN: 0975-3397, Vol. 02, No. 04, 2010 , 1064-1066
[24] Ali Jbaeer Dawood, “Improved Efficiency of Round Robin Scheduling Using Ascending Quantum and Minumium-Maxumum Burst Time”, Journal of university of anbar for pure science, ISSN: 1991-8941, Vol. 6, No. 2, 2012.
[25] “A.S. Tanenbaum, 2008” Modern Operating Systems, Third Edition, Printice Hall ,ISBN : 13:9780136006633,PP: 1104,
[26] Silberschatz, A., P.B. Galyin and G.Gange, 2004,“ Operating System Concepts”. 7th Edn, John Wiley and Sons, USA, ISBN: 13:978-0471694663, PP: 944.
[27] William Stalling, 2006, “Operating system”, 5th Edition Person Education , ISBN :81311703045,
[28] Dhamdhere ,Systems Programming and Operating Systems SECOND EDITOR.
[29] R. Buyya, C. S. Yeo, and S. Venugopal. Market- oriented cloud computing: Vision, hype, and reality for delivering IT services as computing utilities. In Proceedings of the 10th IEEE International Conference on High Performance Computing and Communications, 2008.
[30] Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS Press, USA), Melbourne, Australia, December 5-7, 2011.
[31] Rodrigo N. Calheiros, Rajiv Ranjan, Anton Beloglazov, Cesar A. F. De Rose, and Rajkumar Buyya, CloudSim: A Toolkit for Modeling and Simulation of Cloud Computing Environments and Evaluation of Resource Provisioning Algorithms, Software: Practice and Experience (SPE), Volume 41, Number 1, Pages: 23-50, ISSN: 0038-0644, Wiley Press, New York, USA, January, 2011. (Preferred reference for CloudSim)
[32] Bhathiya Wickremasinghe, Rodrigo N. Calheiros, Rajkumar Buyya, CloudAnalyst: A CloudSim-based Visual Modeller for Analysing Cloud Computing Environments and Applications, Proceedings of the 24th International Conference on Advanced Information Networking and Applications (AINA 2010), Perth, Australia, April 20-23, 2010.
[33] Rajkumar Buyya, Rajiv Ranjan and Rodrigo N. Calheiros, Modeling and Simulation of Scalable Cloud Computing Environments and the CloudSim Toolkit: Challenges and Opportunities, Proceedings of the 7th High Performance Computing and Simulation Conference (HPCS 2009, ISBN: 978-1-4244-4907-1, IEEE Press, New York, USA), Leipzig, Germany, June 21-24, 2009.