auto-scaling

Multi-Tenant software acts out based on auto-scale instance applications due to fluctuating workloads affected by increasing or decreasing the number of tenant demands and requested resource volumes. The aim of auto-scaling is better resource utilization of resource computing as well as provision of good Quality of Service (QoS) to tenants. Auto-scaling approach for meeting its used goal has challenges that consist of predicting workload, identifying correct resource requirement according to workload and selecting the policy of system for resource allocation with the lowest cost. In this research, a runtime auto-scaling mechanism is provided for multi-tenant software in order to answer mentioned challenges. First, due to lack of comprehensive description of a runtime system of multi-tenant software and based on found evidence of various studies, an architecture for runtime system of multi-tenant software is provided and a computing model is introduced that has three various granularity for its module of multi-tenant software. Then by providing an architecture for auto-scaling module of runtime system of multi-tenant software and using sub -modules that have appropriate functionality, mentioned challenges of auto-scaling are answered. To evaluate this, the proposed auto-scaling mechanism is implemented in the cloudism simulation environment and is tested and compared to the recent similar work in the same environmental conditions. The obtained results indicate that the provided auto-scaling mechanism compared to similar work despite the close number of violation of QoS, has better utilization and wastes computing resources less [13/28%-16/19%] with 99% confidence level.