Multitenant Resource Allocation

Multitenant resource allocation is the distribution and assignment of application instances to individual software tenants. It is primarily used in cloud computing, where multitenancy is the backbone architecture. The possibility for multiple users to be assigned unique instances of a single software application in a shared environment offers considerable cost savings.

Dispensing resources can be a tricky affair. Back in the days of the mainframe computer, access to processing was allocated in small slices of time. Now that cloud computing is available, users share resources through what is called a multitenancy architecture. How cloud computing applications are shared is the nature of multitenant resource allocation.

Multitenancy makes it possible for each user to have his or her own instance of a shared application. This attribute can apply to any or all three layers of the cloud, IaaS, PaaS and SaaS. Involved in this process are various controlling practices such as secured access and metered usage. Each tenant must have his or her own individual secure computing environment. Various scenarios are possible, but each tenant remains isolated and invisible to other tenants.

Degrees of multitenancy can be defined in the architecture. It is possible for IaaS and PaaS to be multitenant, while SaaS is not. Multitenancy is accomplished through the creation of a database schema. There are different approaches to managing a multitenant data architecture. Microsoft identifies three:

• Separate databases
• Shared database, separate schemas
• Shared database, shared schema

How multitenancy is configured differs with each provider. The granularity of tenancy applies to the application level. Separate instances of software are defined in the data.