In a computing environment, the idea of tenancy applies at different levels from infrastructure
(like storage) at the lowest layer up to application interface at the top. Similarly in cloud
computing, the multi-tenancy is not limited at IaaS level, rather it covers PaaS and SaaS also.
The consumers there enjoy the facility at various levels depending on the degree of multi
tenancy offered by a cloud service. However it is evident that by incorporating multi-tenancy at
the infrastructure level, all layer of cloud services automatically become multi-tenant to some
degree; but that should not encourage anyone to limit multi-tenancy at IaaS level only, rather it
should be implemented to its highest degree.
At IaaS level, the multi-tenancy provides shared computing infrastructure resources like
servers, storages etc. At this level, multi-tenancy is achieved through virtualization of resources
and different consumers share same set of resources through their virtual representation
without affecting or being aware about one another.
At PaaS level, the multi-tenancy means sharing of operating system by multiple applications.
Applications from different vendors (tenants) can be run over same OS instance (to be offered
as SaaS). This removes the need of allocating separate virtual machines per application by
improving the maintenance and utilization of OS level capabilities.At SaaS level, the multi-tenancy refers to the ability of a single application instance and/
or database instance (that is one database instance being created in some database servers)
in order to serve multiple consumers. Consumers (tenants) of SaaS share same application
code base as well as database tables and codes (like procedure, functions etc.). Data of multiple
consumers which are stored in same set of tables are differentiated by the respective consumer
numbers. Here, the separation of data is logical only although consumers get the feeling
of physical separation. For application, the tenants may have the capability of customizing
application functionalities or view of application interface but they cannot edit application
code as the same application instance serves other consumers (tenants) also. Multi-tenancy
eases application maintenance (like updates) and makes it economical for provider as well as
for the consumers. In single-tenancy model, each consumer can be given the rights of the edit
to application code as separate application instance is maintained for every consumers.
Not only at IaaS layer, multi-tenancy also works at all other levels of cloud services.
In a computing environment, the idea of tenancy applies at different levels from infrastructure
(like storage) at the lowest layer up to application interface at the top. Similarly in cloud
computing, the multi-tenancy is not limited at IaaS level, rather it covers PaaS and SaaS also.
The consumers there enjoy the facility at various levels depending on the degree of multi
tenancy offered by a cloud service. However it is evident that by incorporating multi-tenancy at
the infrastructure level, all layer of cloud services automatically become multi-tenant to some
degree; but that should not encourage anyone to limit multi-tenancy at IaaS level only, rather it
should be implemented to its highest degree.
At IaaS level, the multi-tenancy provides shared computing infrastructure resources like
servers, storages etc. At this level, multi-tenancy is achieved through virtualization of resources
and different consumers share same set of resources through their virtual representation
without affecting or being aware about one another.
At PaaS level, the multi-tenancy means sharing of operating system by multiple applications.
Applications from different vendors (tenants) can be run over same OS instance (to be offered
as SaaS). This removes the need of allocating separate virtual machines per application by
improving the maintenance and utilization of OS level capabilities.At SaaS level, the multi-tenancy refers to the ability of a single application instance and/
or database instance (that is one database instance being created in some database servers)
in order to serve multiple consumers. Consumers (tenants) of SaaS share same application
code base as well as database tables and codes (like procedure, functions etc.). Data of multiple
consumers which are stored in same set of tables are differentiated by the respective consumer
numbers. Here, the separation of data is logical only although consumers get the feeling
of physical separation. For application, the tenants may have the capability of customizing
application functionalities or view of application interface but they cannot edit application
code as the same application instance serves other consumers (tenants) also. Multi-tenancy
eases application maintenance (like updates) and makes it economical for provider as well as
for the consumers. In single-tenancy model, each consumer can be given the rights of the edit
to application code as separate application instance is maintained for every consumers.
Not only at IaaS layer, multi-tenancy also works at all other levels of cloud services.