Birds View
+ +A Strolch agent's architecture can be seen as a simple three-tier architecture. The presentation layer is + mostly a web frontend, where the communication with the agent is done via REST API calls.
+ +The agent itself implements the business logic using Services, Commands, Queries etc.
+ +The agent can communicate with other 3rd systems using any API, where it is preferred to use JSON over + REST.
+ +The agent can use a standard RDBMS as a storage system, where currently DAOs have been implemented only for + PostgreSQL. Should it be required, then any JDBC cabable RDBMS can be used, as no PostgreSQL specific SQL + commands are used.
+ +The following diagram helps visualize this:
+ +
+
+ + +
Squirrel View
+ +The following diagram shows a more detailed view of the architecture of a Strolch Agent.
+ +
+
+ A Strolch agent consists of the following main parts:
+-
+
- REST Endpoints → expose an API to access the Strolch agent outside of the Java VM +
- Services and Commands → implements business logic +
- Queries → implements specific queries against the Strolch model +
- Components → Implements additional logic, which is best implement as a component. E.g. active + components which have threads, etc. + +
- Realms → implements multi-tenant capabilities +
In addition to the main parts, Strolch contains inherit capabilities, which gives Strolch unique features + when compared to other Java Frameworks:
+-
+
- Privileges → Strolch is user agnostic and any action, i.e. Service, Query, etc. is authorized + against the authenticated user. + +
- Transactions → Transactions handle locking/unlocking of objects, updating the model and are the + central API for the developer. + +
- Observers → modifications to the model are propagated to listeners using the observer pattern. +
- Versioning → modifications to objects are versioned and thus can be rolled back at a later time. + +
- Policies → Policies allow injecting different algorithms. All root elements can store Policy + definitions, so that a service can delegate to a Policy and thus behave differently, depending on the + element being accessed. + +