Differences between single-tenant and multi-tenant SaaS architectures

The trick about selecting the appropriate SaaS architecture is understanding what database design, isolation model, and resource distribution model align with your goals. But before that, you need to compare single-tenant vs. multi-tenant architectures to understand which one suits your project. And we’re here to help.

Acropolium is a software development company with a team of experienced cloud computing consultants. In other words, we know what we’re talking about. In this article, we’ll cover the benefits of single-tenancy and multi-tenancy architectures in SaaS applications. Plus, we will explain how to migrate an isolated infrastructure to a scalable multi-tenancy environment. Let’s get to it straight away!

Single-tenant database design

Single-tenant SaaS architecture explained

Single-tenant architecture is a cloud computing environment where clients (tenants) have an isolated application, database, and supporting infrastructure. So far so good. Now, let’s dedicate a moment to talk about the concept of tenancy before we explain how the single-tenant structure works.

Tenancy refers to the way customers (tenants) share computing resources in SaaS (Software as a Service) environments. Metaphorically speaking, single-tenant architecture resembles a suburban neighborhood with private houses.

Your data and computing resources are located in isolated clusters in a single-tenant SaaS separated from other tenants. This gives you the freedom to fully customize, upgrade, and manage your environment.

Single-tenancy is typical for private cloud environments and enterprise-grade SaaS services. For example, Oracle Cloud hosts segregated compartments with isolated resources and granular access control. Every customer has a different product version and has to upgrade it manually, making it a single-tenant platform.

Single-tenant SaaS architecture pros and cons

Now, why do organizations choose single-tenant architecture?

Advanced data security

Single-tenant architecture customers store their application instances and databases on dedicated servers. They can also implement proprietary security tools, role-based access control, and multi-factor authentication to boost cybersecurity. This means your infrastructure remains safe even if tenants on the same SaaS platforms suffer from a data breach.

Single-tenant users can have their data continuously backed to an isolated component of the SaaS servers. At the same time, convenient access to dedicated backup storage helps your team restore previous configurations much faster during emergencies.

Complete control

Single-tenancy SaaS users can purpose-built their software around their business needs and have complete control over the customization. You’re not bound to the infrastructure and can upgrade your software individually. Additionally, you can implement any custom and third-party modules into your platform.

Reliable performance

Single-tenancy customers benefit from isolated cloud environments with dedicated databases, applications, memory, and CPU. This means that other clients’ problems and resource consumption won’t affect you. Plus, you are less likely to use overhead resources during software development.

Single-tenancy has its share of shortcomings, though. This model comes at a premium price because there’s only one customer per environment. If you identify inefficiencies in resource usage, you won’t scale the single-tenant infrastructure as easily as you would in a multi-tenant SaaS.

Plus, single-tenant platforms have a complex onboarding process because the SaaS provider and your team must configure the infrastructure around your needs. You’ll also have to regularly maintain and update your systems, adding up to the lists of expenses. Coincidentally, a lot of single-tenancy disadvantages are the perks of multi-tenancy. Have a look.

Multi-tenant database design pros and cons

Architectures of multi-tenant SaaS models

Multi-tenant architecture is a cloud environment where multiple customers share software instances and the supporting infrastructure.

If single-tenancy is comparable to suburban households, multi-tenancy resembles an apartment building. Tenants keep their belongings locked in their flats, but they have the same doorman, corridors, and communal facilities.

Multi-tenancy platforms have to separate their customers to ensure the security and confidentiality of their data. SaaS providers actually use different strategies to isolate tenants:

  • Shared database. Tenants share resources and storage with a single database divided into identifier columns (one for each client).
  • Dedicated database. The model consists of resource groups, with each tenant in a group having a separate database. The vendor moves these databases between resource groups to optimize resource usage.
  • Sharded databases. Tenant data is split into movable “shards” across several databases.
  • Hybrid-sharded databases. Some providers move tenant resources between dedicated and shared databases. This strategy is better suited for platforms with subscription tiers (for example, a free tier and enterprise-level plans).

The common examples of a multi-tenant SaaS include non-corporate emails clients (Gmail and Yahoo), cloud hosting services (Google Drive and OneDrive), and website builders (Shopify). Enterprise-level platforms like Amazon Web Services (AWS) offer a multi-tenancy infrastructure but also have dedicated single-tenant and mixed options.

Read also: Cloud cost optimization strategies we follow.

Benefits of multi-tenant SaaS architecture

So, what are the advantages of a multi-tenant cloud platform? Let’s go through the main ones:

Resource distribution

Multi-tenant SaaS providers use load balancers to allocate application data between databases and servers. This ensures that the infrastructure makes the most of the available resources to handle heavier workloads.

Fast scaling

Scaling has fewer infrastructure implications for multi-tenancy because clients use the same software and hardware. With multi-tenancy, you can quickly add or remove resources based on your computing and business needs.

Automated maintenance

Maintenance is included in the price of the subscription in multi-tenant SaaS models. The vendor takes care of the servers, security, and software updates, so their tenants can focus on other goals.

Lower cost

Multi-tenancy platforms give you access to complex infrastructure with large amounts of computational power for a smaller price. For example, a single Amazon data node can hold application data for millions of tenants. As you can imagine, maintaining one node with multiple clients is far cheaper than taking care of every client individually.

Compliance management

Multi-tenancy platforms adhere to major regulatory standards, so you don’t have to worry about compliance. Some SaaS solutions offer policy templates to help you develop compliant software (for example, PCI DSS for FinTech or HIPAA for healthcare apps).

Easy onboarding

Multi-tenant SaaS environments have straightforward setup and configuration processes. Often you just have to sign up to start using the platform. In addition to that, the user-friendly interface allows you to easily customize the accounts, add users, and implement third-party services without the provider’s administrative support.

Migration

Moving your data and code between databases in a single environment is nearly hassle-free. Plus, a multi-tenant infrastructure isn’t tailored for specific configuration (like in single-tenant architecture). This means you don’t have to re-architect your environment when migrating your workload to another platform. However, the multi-tenant model is not without its limitations. Customers share databases and servers, which creates cybersecurity concerns. You also have to depend on the provider to fix the system’s vulnerabilities. On top of that, this architecture is limited in terms of customization and third-party integrations.

Key differences between single-tenant and multi-tenant architecture types

Comparison of single-tenant and multi-tenant architectures

For your convenience, we summed up the main features of single-tenant and multi-tenant SaaS architectures in this table.

Single-tenant SaaSMulti-tenant SaaS
IsolationA dedicated software application, server, and database for every clientA single database or application instance shared between clients
AffordabilityPremium price and the need to invest in maintenance, setup, hosting, and infrastructure updatesClients spend less money because providers maintain and update the infrastructure
PerformanceThe application’s performance doesn’t depend on other clientsThe application performance depends on your tier, provider, and resources used by other clients
SecurityReliable and isolated databases with convenient backup solutionsClients share the same environment and depend on the vendor’s security measures
ScalabilityReliable and isolated databases with convenient backup solutionsClients share the same environment and depend on the vendor’s security measures
CustomizabilityClients can fully customize their software and user interfaceCustomization is limited but easier to implement with supported tools
OnboardingThe onboarding process is costly and time-consumingMulti-tenant solutions have automated setup and intuitive configuration

In short, single-tenancy architectures have robust cybersecurity, a dedicated resource pool, and reliable performance for a premium price. Multi-tenant platforms are riskier, but they are much cheaper, flexible, and virtually maintenance-free.

Now you have a lot of information to process before you answer the main question: what type of architecture is the best one for your project?

Read also: Best backend frameworks we recommend.

Should you choose single-tenancy or multi-tenancy?

Architectures of single-tenant vs. multi-tenant and their use cases

Allow us to help you answer the question.

Single-tenant SaaS works for large enterprises that want full control and robust security. This model works for healthcare and FinTech companies responsible for client’s personally identifiable information. Single-tenancy is also an excellent solution for B2B businesses whose eCommerce platforms rely on complex workflows and ERP tools.

On the other hand, multi-tenancy solutions are perfect for companies that want an easily configurable and reasonably priced solution with fewer hardware requirements. This is a great option for startups, medium businesses, and larger companies that constantly readjust their scaling expenses.

Have you made your decision yet? If you’re going for multi-tenancy, it’s important to learn how to implement it.

How to implement multi-tenant architecture

Illustration of a SaaS application in a multi-tenant environment

Businesses can use on-demand cloud computing platforms like AWS to build a multi-tenant SaaS application. The most popular options you can go with include:

  • Amazon ECS (microserver architecture). ECS has a loosely coupled architecture, meaning their components aren’t dependent on each other. This gives your teams the possibility to code, scale, and deploy code independently. However, you won’t port your data to another cloud without re-architecting the whole infrastructure.
  • Amazon EKS (Elastic Kubernetes Services). EKS adds a layer of complexity to Amazon ECS and allows deeply customizable SaaS configurations. You can also isolate tenants in different Kubernetes clusters to boost security.
  • Amazon Serverless Computing. Serverless is a fully scalable and cost-effective AWS architecture where they charge based on the resources you use. This is also the most complex architecture that might require you to refactor the entire SaaS application.

You also need to implement an authorization server and domain route module to segregate users in your SaaS application.

Authorization (identity) server

AcroSSO authentication tool for multi-tenant SaaS environments

The authorization server identifies tenants as they access the SaaS application. However, the system has to do much more than just verify credentials. When someone wants to access your environment, the server must check his affiliation and role in the organization. Then, the system passes the information to the application and issues a token based on the user’s access rights.

Companies use third-party tools to optimize resource-heavy authentication & authorization processes. Many of our clients rely on AcroSSO — a backend authorization management service made by Acropolium. This solution is designed to easily manage and control user and service rights in corporate information networks (primarily multi-tenant SaaS environments).

Domain route

You need to implement the right URL design for a multi-tenant SaaS. Organizations with fewer clients can go with logical and keyable URLs to separate their domains. But global businesses that prioritize security can go with cryptic addresses lines or block access requests made without a valid session. Now, if you’ve seen that multi-tenant architecture works best for your existing SaaS, migrating to it isn’t a big problem.

Learn more: Microservices Architecture Implementation.

Migrating from single-tenant to multi-tenant cloud architecture

Types of migration models according to AWS

Migration from single-tenant environments to multi-tenancy isn’t uncommon because many projects started with isolated cloud infrastructures. Here’s how you can make the transition as resource- and cost-effective as possible.

To convert your on-premise or single-tenant infrastructure to the multi-tenant environment, you have to start with the migration model and methodology. The common approaches include:

  • Silo migration: moving the existing stack with minimal restructuring
  • Layered migration: moving web and app tiers and partially optimizing them in phases
  • Service-by-service migration: restructuring and optimizing every component of your architecture in increments

You’ll have to choose the database isolation model based on the number of user groups and the required level of security. Next, you’ll need to add the authorization server and ensure its compatibility with all your apps or services that access dedicated databases or a shared one.

But before all that, a successful SaaS migration requires a detailed product roadmap, an efficient methodology, an experienced team with an appropriate tech stack. Acropolium has all of that and can help you move your infrastructure with minimal disruption to your business.

Conclusion

There’s always a tradeoff when it comes to selecting an architecture type. You have to choose between the security compliance and reliability of single-tenancy vs. the flexibility and cost-efficiency of multi-tenancy.

Most importantly, companies need to be meticulous when planning their infrastructure. You must consider resource usage needs, budget, partition (isolation) model, and cybersecurity tools. Thankfully, Acropolium can help.

Our company can supply you with teams of cloud computing consultants, web developers, architects, and project managers. With our skills and tech stack, you can migrate your entire infrastructure or build a successful multi-tenant system from scratch. Get in touchto see what we have to offer!