Fail Over Strategy for Fault Tolerance in Cloud Computing Environment

YesCloud fault tolerance is an important issue in cloud computing platforms and applications. In the event of an unexpected system failure or malfunction, a robust fault-tolerant design may allow the cloud to continue functioning correctly possibly at a reduced level instead of failing completely. To ensure high availability of critical cloud services, the application execution and hardware performance, various fault tolerant techniques exist for building self-autonomous cloud systems. In comparison to current approaches, this paper proposes a more robust and reliable architecture using optimal checkpointing strategy to ensure high system availability and reduced system task service finish time. Using pass rates and virtualised mechanisms, the proposed Smart Failover Strategy (SFS) scheme uses components such as Cloud fault manager, Cloud controller, Cloud load balancer and a selection mechanism, providing fault tolerance via redundancy, optimized selection and checkpointing. In our approach, the Cloud fault manager repairs faults generated before the task time deadline is reached, blocking unrecoverable faulty nodes as well as their virtual nodes. This scheme is also able to remove temporary software faults from recoverable faulty nodes, thereby making them available for future request. We argue that the proposed SFS algorithm makes the system highly fault tolerant by considering forward and backward recovery using diverse software tools. Compared to existing approaches, preliminary experiment of the SFS algorithm indicate an increase in pass rates and a consequent decrease in failure rates, showing an overall good performance in task allocations. We present these results using experimental validation tools with comparison to other techniques, laying a foundation for a fully fault tolerant IaaS Cloud environment

Mobile cloud healthcare systems using the concept of point–of–care

Recent years have witnessed a rapid growth in delivering/accessing healthcare services on mobile devices. An example of a health practice/application that is benefiting from the mobile evolution is m–health, which is aimed at providing health services to mobile devices on the move. However, mobile devices have restricted computational and storage capacity, and run on batteries that have limited power. These limitations render m–health unable to run the demanding tasks that may be required for accessing/providing health services. The mobile cloud has recently been proposed as a solution for dealing with some of the limitations of mobile devices, such as low storage and computing capacity. However, introducing this solution into the m–health field is not straightforward, as the integration of this technology has specific limitations, such as disconnection issues and concerns over privacy and security. This thesis presents research work investigating the ability to introduce mobile cloud computing technology into the health field (e.g., m–health) to increase the chances of survival in cases of emergencies. This work focuses on providing help to people in emergencies by allowing them to seek/access help via mobile devices reliably and confidently, as well as the ability to build a communication platform between people who require help and professionals who are trusted and qualified to provide it. The concept of point–of–care has been used here, which means providing as much medical support to the public as possible where and when it is needed. This thesis proposes a mobile cloud middleware solution that enhances connectivity aspects by allowing users to create/join a mobile ad–hoc network (MANET) to seek help in the case of emergencies. On the other side, the cloud can reach users who do not have a direct link to the cloud or an Internet connection. The most important advantage of combining a MANET and a mobile cloud is that management tasks such as IP allocation and split/merge operations are shifted to the cloud, which means resources are saved on the mobile side. In addition, two mobile cloud services were designed which have the aim of interacting with users to facilitate help to be provided swiftly in the case of emergencies. The system was deployed and tested on Amazon EC2 cloud and Android–based mobile devices. Experimental results and the reference architecture show that the proposed middleware is feasible and meets pre–defined requirements, such as enhancing the robustness and reliability of the system