CHAVE: Resource Consolidation with High Availability on Virtualized Environments

In order to meet the growing demand for business continuity, the adoption of cloud computing platforms is growing to keep its critical services. However, availability rates established in service level agreements (SLA) by cloud service providers (CSP) does not always meet their demand for high-availability (HA). Services replicated in multi-AZs architecture result in high costs due to the inherent increase in the load of the physical servers, resulting in higher consumption of energy. In this way, virtual machine (VM) consolidation stands out as an energy efficiency strategy based on virtual resource scheduling, allowing to reduce energy consumption as well as improve the organization of fragmented resources. However, when consolidation is applied in conjunction with HA mechanism, there is a risk of violating affinity (MV-server) and anti-affinity (MV-AZ) constraints, thereby violating SLA requirements. Thus, CHAVE presents an on-demand HA mechanism based on Multi-AZ replication, which simultaneously performs a VM consolidation strategy isolated for each AZ, considering its inherent constraints. The numerical results by real-trace driven simulations show that CHAVE, meets 20% of HA requests with energy consumption similar to a CSP that does not apply to consolidation with replication. Additionally, CHAVE does not cause any SLA violations such as overcommiting, or rejection of critical requests.