Service Fabric enables us to build applications that consist of microservices. Stateless micro-service doesn’t maintain a mutable state outside a request. Azure Cloud Service’s worker role is an example of a stateless service. Stateful microservice maintains a mutable, authoritative state beyond the request and its response.
In Microsoft Azure Service Fabric, microservices can be categorized into stateful and stateless based on how they manage and store data. Here’s an explanation of stateful and stateless microservices in the context of Azure Service Fabric:
- Stateless Microservices:
- Stateless microservices do not maintain any persistent state or data within the service itself.
- They rely on external data stores or services to manage and store their state.
- Stateless microservices are generally easier to scale horizontally since each instance of the microservice is identical and can handle requests independently.
- Examples of stateless microservices include web frontends, API gateways, and some types of data processing services.
- Stateful Microservices:
- Stateful microservices maintain and manage their own persistent state internally.
- They can store data within the microservice itself or use a dedicated state provider like Azure Service Fabric Reliable Collections to handle state.
- Stateful microservices are suitable for scenarios where maintaining state is crucial, such as maintaining session data, managing workflows, or dealing with complex business processes that require state preservation.
- Scaling stateful microservices may require additional considerations, as the state needs to be managed and synchronized across multiple instances.
In Azure Service Fabric, stateful microservices often leverage the Reliable Services programming model, which provides built-in support for managing state through Reliable Collections. This allows developers to build distributed and scalable applications while ensuring that the state is durable and highly available.
In summary, stateless microservices in Azure Service Fabric don’t maintain internal state and rely on external data stores, while stateful microservices manage their own persistent state, either internally or using dedicated state providers like Reliable Collections. The choice between stateful and stateless microservices depends on the specific requirements and characteristics of the application or system being developed.