Towards performance isolation in multi-tenant SaaS applications

Multi-tenancy has shown promising results in achieving high operational cost efficiency by sharing hardware and software resources among multiple customer organisations, called tenants. In the context of cloud computing, this paradigm enables cloud providers to reduce operational costs by dividing resources and to simplify application management and maintenance. Maximum cost efficiency is achieved with application-level multi-tenancy. However, this high level of resource sharing complicates performance isolation between the different tenants, i.e. ensuring compliance with the SLAs of the different tenants and ensuring that the behaviour of one tenant cannot adversely affect the performance of the other tenants. This paper explores the challenges of performance isolation in the context of multi-tenant SaaS applications. In addition, we propose a middleware architecture to enforce performance isolation based on the tenant-specific SLAs, using a tenant-aware profiler and a scheduler. Our prototype reveals promising initial results.