A model for optimising the deployment of cloud-hosted application components for guaranteeing multitenancy isolation.

Tenants associated with a cloud-hosted application seek to reduce running costs and minimize resource consumption by sharing components and resources. However, despite the benefits, sharing resources can affect tenant’s access and overall performance if one tenant abruptly experiences a significant workload, particularly if the application fails to accommodate this sudden increase in workload. In cases where a there is a higher or varying degree of isolation between components, this issue can become severe. This paper aims to present novel solutions for deploying components of a cloud-hosted application with the purpose of guaranteeing the required degree of multitenancy isolation through a mathematical optimization model and metaheuristic algorithm. Research conducted through this paper demonstrates that, when compared, optimal solutions achieved through the model had low variability levels and percent deviation. This paper additionally provides areas of application of our optimization model as well as challenges and recommendations for deploying components associated with varying degrees of isolation

Evaluating the effect of locking on multitenancy isolation for components of cloud-hosted services.

Multitenancy isolation is a way of ensuring that the performance, stored data volume and access privileges required by one tenant and/or component does not affect other tenants and/or components. One of the conditions that can influence the varying degrees of isolation is when locking is enabled for a process or component that is being shared. Although the concept of locking has been extensively studied in database management, there is little or no research on how locking affects multitenancy isolation and its implications for optimizing the deployment of components of a cloud-hosted service in response to workload changes. This paper applies COMITRE (Component-based approach to Multitenancy Isolation through Request Re-routing) to evaluate the impact of enabling locking for a shared process or component of a cloud-hosted application. Results show that locking has a significant effect on the performance and resource consumption of tenants especially for operations that interact directly with the local file system of the platform used on the cloud infrastructure. We also present recommendations for achieving the required degree of multitenancy isolation when locking is enabled for three software processes: continuous integration, version control, and bug tracking