eng Science and Education Publishing Journal of Computer Sciences and Applications 2328-725X 2016-03-01 4 1 9 13 10.12691/jcsa-4-1-2 JCSA2016412 article Taskeen Zaidi Rampratap taskeenzaidi867@gmail.com 1 Faculty of Computer Science & Engineering, Shri Ramswaroop Memorial University, Deva Road, Lucknow, India Due to emergence of cloud computing, many traditional issues have been eliminated or reduced. Cloud computing is on demand computing in which processing is done on remote computer hence the chances of errors is more due to communication delay, latency or loss of control over computing node. These are the important issue that's why cloud computing infrastructure should be fault tolerant as well as designed to schedule tasks must be properly handled. The present paper deals with the understanding of fault tolerance techniques in cloud environments and comparison with various models on various parameters have been done. Fault tolerance technique is studied with the help of well known object-oriented language Unified Modeling Language and state diagrams are designed and validated through the concepts of Finite State Machine. http://pubs.sciepub.com/jcsa/4/1/2/jcsa-4-1-2.pdf UML cloud computing fault tolerance UML FSM test cases round robin