The consolidation of multiple tenants onto a single RDBMS instance turned out to be benefical with respect to resource utilization and scalability. The consolidation implies that multiple tenants share the physical resources available for the RDBMS instance. If the available resources tend to get insufficient to meet the SLAs agreed with the tenants, migration of a tenant's database from one RDBMS instance to another is compelling. Highly available services demand for live migration techniques that come with minimal service interruption and low performance impact.

This paper meets the demand for live migration techniques by contributing ProRea. ProRea is a live database migration approach designed for multi-tenant RDBMS that run OLTP workloads under snapshot isolation. ProRea extends concepts of existing live database migration approaches to accomplish minimal service interruption, high efficiency and very low migration overhead. Measurements of a prototypical ProRea implementation underpin its good performance.