Cloud computing is a recent, emerging technology in the IT industry. It is an evolution of previous models such as grid computing. It enables a wide range of users to access a large sharing pool of resources over the internet. In such complex system, there is a tremendous need for an efficient load balancing scheme in order to satisfy peak user demands and provide high quality of services. One of the challenging problems that degrade the performance of a load balancing process is bursty workloads. Although there are a lot of researches proposing different load balancing algorithms, most of them neglect the problem of bursty workloads. Motivated by this problem, this paper proposes a new burstness-aware load balancing algorithm which can adapt to the variation in the request rate by adopting two load balancing algorithms: RR in burst and Random in non-burst state. Fuzzy logic is used in order to assign the received request to a balanced VM. The algorithm has been evaluated and compared with other algorithms using Cloud Analyst simulator.  Results show that the proposed algorithm improves the average response time and average processing time in comparison with other algorithms.

Replication is a well known technique to improve reliability and performance for a Data Grid. Keeping consistent content at all distributed replica is an important subject in Data Grid. Replica consistency protocol using classical propagation method called the radial method suffers from high overhead at the master replica site, while line method suffers from high delay time. In Data Grid not all replicas can be dealt with in the same way, since some will be in greater demand than others. Updating first replica having most demand, a greater number of clients would access the updated content in a shorter period of time. In this study, based on asynchronous aggressive update propagation technique, a scalable replica consistency protocol is developed to maintain replica consistency in data grid which aimed to reaching delay reduction and load balancing, such that the high access weight replicas updated faster than the others. The simulation results shows that the proposed protocol is capable of sending the updates to high access replicas in a short period while reducing the total update propagation repose time and reached load balancing.

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