Bosch’s Residential IoT Services GmbH (RIoT) uses Dapr actors and Java SDK to build a large scale smart home IoT solution.
Dapr is set of unified APIs with built-in best practices to build cloud-native event-driven applications. Dapr increases your developer productivity by 20-40% with out-of-the-box features such as workflow, pub/sub, state management, secret stores, configuration stores, bindings, actors and distributed lock and covers cross-cutting concerns including security, observability and resiliency.
Dapr workflow is simplifying complex, stateful coordination requirements in event-driven applications.
Workflow makes it easy to implement orchestration patterns such as task chaining, fan-out/fan-in, monitor, and external system interaction. Workflow can be combined with the other Dapr APIs so developers can automate business processes quickly.
Modern cloud-native applications are inherently async and react to events. Dapr enables the creation of event-driven applications by providing a unified set of APIs across 100+ cloud-native back-ends and brokers. It offers guaranteed message delivery, built-in resiliency, observability and security.
Dapr's component model decouples technology choices from your code making it agnostic to hosting environments and enabling application portability. Dapr runs as a sidecar wherever your application runs whether hosted on Kubernetes, VMs, deployed on the cloud, on-premises or on the edge.
Dapr can be introduced into an existing architecture incrementally. Dapr applications can call non-Dapr endpoints while still having the Dapr benefits of having resiliency policies, observability, security access through scoping and more.
Service invocation enables applications to communicate with each other through well-known endpoints in the form of http or gRPC messages. Dapr provides an endpoint that acts as a combination of a reverse proxy with built-in service discovery, while leveraging built-in distributed tracing and error handling.
Pub/Sub is a loosely coupled messaging pattern where senders (or publishers) publish messages to a topic, to which subscribers subscribe. Dapr supports the pub/sub pattern between applications.
Application state is anything an application wants to preserve beyond a single session. Dapr provides a key/value-based state and query APIs with pluggable state stores for persistence.
An actor is an isolated, independent unit of compute and state with single-threaded execution. Dapr provides an actor implementation based on the virtual actor pattern which provides a single-threaded programming model and where actors are garbage collected when not in use.
The Workflow API enables you to define long running, persistent processes or data flows that span multiple microservices using Dapr workflows or workflow components. The Workflow API can be combined with other Dapr API building blocks.
Dapr provides a secrets building block API and integrates with secret stores such as public cloud stores, local stores and Kubernetes to store the secrets. Services can call the secrets API to retrieve secrets, for example to get a connection string to a database.
The Configuration API enables you to retrieve and subscribe to application configuration items for supported configuration stores. This enables an application to retrieve specific configuration information, for example, at start up or when configuration changes are made in the store.
A binding provides a bi-directional connection to an external cloud/on-premise service or system. Dapr allows you to invoke the external service through the Dapr binding API, and it allows your application to be triggered by events sent by the connected service.
The distributed lock API enables you to take a lock on a resource so that multiple instances of an application can access the resource without conflicts and provide consistency guarantees.
Dapr provides end-to-end security with the service invocation API, with the ability to authenticate an application with Dapr and set endpoint access policies. For pub/sub components, you can limit which topic types and applications are allowed to publish and subscribe to specific topics.
Dapr can be configured to emit tracing data using the widely adopted protocols of Open Telemetry (OTEL) and Zipkin. This makes it easily integrated with multiple observability tools.
Dapr provides a capability for defining and applying fault tolerance resiliency policies to your application. You can define policies for following resiliency patterns: timeouts, retries/back-offs, circuit breakers. These policies can be applied to any Dapr API calls when calling components with a resiliency spec.
