SaaS (software as a service) delivered an explosion in muti-tenant deployments. Is multi-tenancy the right choice for every organization? This article will help companies weigh single tenant vs multi-tenant with definitions and explanations of the benefits, challenges, and differences.
What is multi-tenancy?
An assessment of single tenant vs. multi-tenant starts with a definition of multi-tenancy. A multi-tenant architecture, referred to as multi-tenancy, has all users share access to a common set of infrastructure hardware and software resources. With multi-tenancy, a single infrastructure is used in place of multiple environments.
Multi-tenancy environments have each tenant physically integrated, but logically separated. For example, multiple organizations can share a single instance of configurations, data, user management, and other properties while keeping their data and processes private. In another scenario, a single instance of an application runs on one server and is used by multiple tenants whose data and work remain private.
Three common multi-tenancy models are outlined below. Varying levels of complexity and cost will drive discussions and selection. The models are explained in the context of the relationships between applications and databases.
- Single application with a single database
- Easier scaling
- Low cost for tenants
- Potential performance impact based on other tenant’s activities
- Simplest multi-tenancy environment
- Single application with multiple databases
- Difficult to scale
- Higher cost
- Reduces performance impact of neighbors
- Supports different tenants with different requirements
- Multiple applications with multiple databases
- Complex
- Expensive
- Highly secure
- Tenants partitioned according to their criteria
Cases in which multi-tenancy is the right choice for a software application may include:
- Need to support multiple users in a cost-effective cloud environment
- Want to avoid a large infrastructural footprint
- Lack of resources for a large deployment and the associated maintenance and support
- Require seamless scalability options
- Have a team of experienced developers and architects
For users who are purchasing a software application, multi-tenancy may be the right choice if the organization:
- Allows resource or data sharing
- Is trying to balance performance vs. cost graph in favor of cost savings
- Requires relatively minor configurational customizations
What is single tenancy?
The assessment of single tenant vs multi-tenant continues with a review of the definition of single tenancy. A single tenant architecture runs only one instance of an application and supporting infrastructure for one organization.
As with multi-tenancy, varying levels of complexity and cost will drive the selection of a single tenant architecture. Characteristics of a single-tenant architecture include a high level of user control, especially with regard to:
- Backup capabilities
- Flexibility to address specific environment requirements
- Making updates
- Reliability
- Security
Single tenancy may be the right choice when building a software application if the organization:
- Is comfortable with a large infrastructural footprint
- Does not have to support a lot of customers
- Has no budgetary restrictions
- Needs to provide unparalleled performance and throughput
- Possesses the resources for a large deployment and the associated maintenance and support
Single tenancy may be the right choice when purchasing a software application if the organization:
- Can pay a premium for their selection
- Does not allow resource or data sharing
- Requires extensive configurational customizations
- Does not need to automate upgrades
Single tenant vs multi-tenant
| Single-tenant | Multi-tenant | |
| Availability | Computing resources are dedicated | Computing resources are shared |
| Cost | Single user responsible for all operation costs | Multiple tenants share operation costs |
| Customizability | Environment can be customized | Environment customization is limited to align with industry best practices |
| Efficiency | Resources are fixed, so unused capacity is wasted | Resources are dynamically available, so capacity is available as needed |
| Responsibilities | In-house teams are responsible for maintenance, software updates, patches, backup, restore, and disaster recovery | Provider manages all maintenance software updates, patches, backup, restore, and disaster recovery |
| Set up | Requires time and expertise | Out-of-the-box |
| Type of cloud | Private cloud | Public cloud |
| Updates | Each instance updated separately | Make updates to a single, shared instance |
| Use cases | Custom apps Private clouds | Consumer-facing apps SaaS Public clouds |
Benefits of multi-tenancy
Reduced costs
- Flexible payment models: Pay-as-you-go, monthly or annual subscriptions based on the number of users, usage level, or data volume
- Operations costs shared by all tenants (e.g., hardware, software, maintenance, and support)
Flexible scalability
- Increase or decrease resources to extend capacity or eliminate unused resources
- Seamlessly add new users
Does not require maintenance
- All maintenance is included, such as installing software updates and patches, maintaining availability, and managing backups
- No need to have expert resources in-house
Better overall security
- Security and privacy of the data processed on the multi-tenant cloud are supported and maintained by the service provider
- Consolidated resources can more effectively manage threat and intruder detection and prevention
- Physical and logical access controls are more stringent and tightly managed
What’s SaaS got to do with it?
Software as a service (SaaS) is one of the largest examples of multi-tenancy. A SaaS solution can run one instance of its application on one instance of a database, providing multiple tenants access via web access, with each tenant having a unique, private subdomain to access their part of the service.
Challenges with single tenancy
Reasons the single tenant vs. multi-tenant decision leads to multi-tenancy include single tenancy drawbacks such as:
- Cumbersome management and maintenance
- High costs
- Inefficient resource usage
- Requirement for dedicated administrative support
- Time-consuming and complex deployments
Single tenant vs multi-tenant: Take time to make an informed decision
Ultimately, the single tenant v. multi-tenant decision rests on use cases, resources, and budget. Organizations are encouraged to take time to carefully evaluate single tenant vs multi-tenant solutions before making their decisions, as rearchitecting solutions and deployments can be expensive and time-consuming, in some cases even impacting the company’s ability to grow and scale.
