Hybrid SaaS deployment - SaaS Lens

This whitepaper contains additional guidance not found in the SaaS Lens of the AWS Well-Architected Tool.

Hybrid SaaS deployment

The needs of customers in SaaS environments can vary significantly for a business. While there are significant cost and operational advantages to building a SaaS solution that has all customers running in shared infrastructure model (pool), there might be times when customers are not willing to share infrastructure resources with other tenants.

This need for one-off customers to have their own environment can be challenging for SaaS providers. While SaaS providers feel the business pressure to support this model, they also know that supporting variations of this nature will undermine the overall SaaS goals of the business. Each new one-off customer can add operational overhead and complexity. As each new customer is added in this model, you quickly find yourself sliding further away from the innovation, agility, and cost efficiency benefits that come from a shared infrastructure model.

There are, however, architectural and operational strategies that can embrace this model without fully compromising your SaaS vision. The diagram in Figure 9 provides a conceptual view of how you could address this challenge.

Figure 9: Hybrid deployment model

In this diagram, you’ll notice that we have two separate deployments of our SaaS environment. The left side is deployed in a pooled model with shared infrastructure. The majority of our tenants are running in this environment. However, on the right side, we’ve deployed a separate copy of the multi-tenant environment that is hosting one tenant (tenant 4).

The key to this strategy is that both environments (the left and right) are running the same version of the SaaS application. Any new changes or updates are applied to both environments at the same time. More importantly, you’ll see that we have a single, unified management experience that spans both of these environments. Onboarding, identity, metering, and billing are shared and common to both environments.

This shared experience allows a SaaS organization to manage and operate these environments through a single pane of glass. By fitting these one-off tenants into this model, you’re able to minimize the impact to the overall agility and operational efficiency of your SaaS environment. This model impacts cost efficiency and adds operational complexity. However, it can represent a reasonable compromise for many SaaS companies.