Choosing a Model
Start with the simplest model that meets your current requirements.
All-In-One is the right default for most new deployments.
Move to Distributed when you need managed database infrastructure or when the database and service tiers need to scale at different rates.
Move to Clustered when individual services need to absorb traffic spikes independently or when your availability requirements exceed what a single replica can provide.
These models are not mutually exclusive.
A production system might use Distributed for its database tier and Clustered for one or two high-traffic microservices while the rest run as single replicas.
Because each component is independent, you can apply the right scaling decision to each piece without committing the entire system to one topology.