Multitenancy is an IT systems architecture based on the concept that deployed resources such as compute, storage, networking, etc., need to be shared amongst multiple, independent "tenants" (i.e. users, user groups, or companies). By definition, multitenancy must be secure and the key requirements are:
- No tenant can access or even know of the existence of the resources allocated to other tenants. In other words one tenant can't have any visibility of or access to the resources of another tenant (e.g. the paths, luns, etc).
- Security must be role-based. A secure management capability must allocate resources without divulging the contents of those resources even to an overall administrator. The overall administrator can allocate additional resources and will have knowledge of what resources are setup and deployed, however that overall administrator won't be able to perform functions often associated with single tenant environments (e.g. copying data).
- Tenant administration must be role based. In a multitenant environment, the tenant admin is able to distribute the management and access capabilities to appropriate administrators within the tenant.
Why is Multitenancy Important?
Multitenancy is critical in today's IT environment due to the popularity of cloud computing and virtualization. These approaches to technology platform deployment by their very nature share resources among multiple groups. As such, multitenancy is becoming increasingly a pre-requisite for many organizational deployments.
Many vendor organizations claim secure multitenancy capability. However users need to be careful to evaluate the degree to which vendors and cloud service providers deliver multitenancy. Specifically, many suppliers do not have support for role-based administration, a critical piece of the puzzle. Role-based administration is non-trivial because the architecture of the system must have integrated the security mechanisms on the individual resources together with the management system itself.
Users that want to understand the 'gold standard' of secure multitenancy should observe the capabilities of IBM's mainframe Resource Access Control Facility (RACF).