Monthly Archives:September 2021

The Mixed-Mode Deployment Model – Multi-Tenant Deployment Models

September 17th, 2021 / Categories: AWS Certification Exam, Exams of Microsoft, Introducing the Silo and Pool Models, Picking Technologies for Your Planes / No Comments »

The Mixed-Mode Deployment Model

To this point, I’ve focused heavily on the full stack models. While it’s tempting to view multi-tenant deployments through these more coarse-grained models, the reality is that many systems rely on a much more fine-grained approach to multi-tenancy, making silo and pool choices across the entire surface of their SaaS environment. This is where we look more at what I refer to as a mixed mode deployment model.

With mixed mode deployments, you’re not dealing with the heavy absolutes that come with full stack models. Instead, mixed mode allows us to look at the workloads within our SaaS environment and determine how each of the different services and resources within your solution should be deployed to meet the specific requirements of a given use case.

Let’s take a simple example. Imagine I have two services in my e-commerce solution. I have an order service that has challenging throughput requirements that are prone to noisy neighbor problems. This same service also stores data that is going to grow significantly and has strict compliance requirements that are hard to support in a pooled model. I also have a ratings service that is used to manage product ratings. It doesn’t really face any significant throughput challenges and can easily scale to handle the needs of tenants–even when a single single tenant might be putting a disproportionate load on the service. Its storage is also relatively small and contains data that isn’t part of the system’s compliance profile.

In this scenario, I can step back and consider these specific parameters to arrive at a deployment strategy that best serves the needs of these services. Here, I might choose to make both the compute and the storage of my order service siloed and the compute and storage of my rating service pooled. There might even be cases where the individual layers of a service could have separate silo/pool strategies. This is the basic point I was making when I was first introducing the notion of silo and pool at the outset of this chapter.

Equipped with this more granular approach to silo and pool strategies, you can now imagine how this might yield much more diverse deployment models. Consider a scenario where you might use this strategy in combination with a tiering model to define your multi-tenant deployment footprint.

The image in Figure 3-11 provides a conceptual view of how you might employ a mixed mode deployment model in your SaaS environment. I’ve shown a variety of different deployment experiences spanning the basic and premium tier tenants.

Figure 3-11. A mixed mode deployment model

The Mixed-Mode Deployment Model 2 – Multi-Tenant Deployment Models

September 16th, 2021 / Categories: AWS Certification Exam, Exams of Microsoft, Introducing the Silo and Pool Models, The Full Stack Pool Model / No Comments »

On the left-hand side of this image, we have our basic tier services. These services cover all the functionality that is needed for our SaaS environment. However, you’ll note that they are deployed in different silo/pool configurations. Service 1, for example, has siloed compute and pooled storage. Meanwhile, Service 2 has siloed compute and siloed storage. Services 3-6 are all pooled compute and pooled storage. The idea here is that I’ve looked across the needs of my pooled tenants and identified, on a service-by-service basis, which silo/pool strategy will best fit the needs of that service. The optimizations that have been introduced here were created as baseline strategies that were core to the experience of any tenant using the system.

Now, where tiers do come into play is when you look at what I’ve done with the premium tier tenants. Here, you’ll notice that Services 5 and 6 are deployed in the basic tier and they’re also deployed separately for a premium tier tenant. The thought was that, for these services, the business determined that offering these services in a dedicated model would represent value that could distinguish the experience of the system’s premium tier. So, for each premium tier tenant, we’ll create new deployments of Service 5 and 6 to support the tiering requirements of our tenants. In this particular example, Tenant 3 is a premium tier tenant that consumes a mix of the services on the left and these dedicated instances of Services 5 and 6 on the right.

Approaching your deployment model in this more granular fashion provides a much higher degree of flexibility to you as the architect and to the business. By supporting silo and pool models at all layers, you have the option to compose the right blend of experiences to meet the tenant, operational, and other factors that might emerge throughout the life of your solution. If you have a pooled microservice with performance issues that are creating noisy neighbor challenges, you could silo the compute and/or storage of the service to address this problem. If your business wants to offer some parts of your system in a dedicated model to enable new tiering strategies, you are better positioned to make this shift.

This mixed mode deployment model, in my opinion, often represents a compelling option for many multi-tenant builders. It allows them to move away from having to approach problems purely through the lens of full stack solutions that don’t always align with the needs of the business. Yes, there will always be solutions that use the full stack model. For some SaaS providers, this will be the only way to meet the demands of their market/customers. However, there are also cases where you can use the strengths of the mixed mode deployment model to address this need without moving everything into a full stack silo. If you can just move specific services into the silo and keep some lower profile services in the pool, that could still represent a solid win for the business.