The major benefit of multi-tenancy is cost saving due to infrastructure sharing and the operational efficiency of managing a single instance of the application across multiple customers or tenants. However, multi-tenancy introduces complexity. Issues can arise when a tenant's action or usage affects the performance and availability of the application for other tenants on the shared infrastructure. In addition, security, customization, upgrades, recovery, and many more requirements of one tenant can create issues for other tenants as well.

Multi-tenancy models may lie anywhere from the share-nothing to share-everything continuum. While technical ease may be a key factor from the IT department's perspective, the cloud architect should never lose sight of the business implications and costs of selecting the approach to multi-tenancy.

Whatever the multi-tenancy model, the data architecture needs to ensure robust security, extensibility, and scalability in the data tier...