Persistence

The FA³ST Registry currently supports two different persistence implementations.

• In-Memory persistence

• JPA-based persistence (relational database)

In-Memory Persistence

The In-Memory Persistence keeps the AAS and Submodel Registry in the local memory. At startup, the Registry always starts empty. All registered AASs or Submodels will be stored in the local memory. When the application is stopped, all registered AASs and Submodels will be lost.

Configuration

The In-Memory Persistence doesn’t require specific settings in the application.properties file.

The property spring.profiles.active must be empty or not set, as the default profile is In-Memory Persistence.

JPA (Java Persistenc API) Persistence

The JPA Persistence keeps the AAS and Submodel Registry in a relational database. When the Registry is restarted, all registered AASs and Submodels will still be availabe, unless you use an In-Memory database like H2. So, when an AAS or Submodel is not available anymore, it’s important to delete it from the Registry.

Currently, the JPA Persistence is configured and tested with PostgreSQL and H2. But other relational databases supported by JPA should also work. In that case, you must make sure, that the corresponding database driver dependency is included in the pom.xml of the service.

Configuration

The JPA Persistence requires some settings in the application.properties file:

Here an example of the settings required for PostgreSQL:

##### RDBS via JPA (external PostgresDB) #####
spring.profiles.active=jpa
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
spring.datasource.driver=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://localhost:5432/fa3st-registry
spring.datasource.username=fa3st-registry
spring.datasource.password=ChangeMe

Here an example of the settings required for H2:

##### RDBS via JPA (in-memory H2) #####
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect
spring.profiles.active=jpa
spring.datasource.driver=org.h2.Driver
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.username=sa
spring.datasource.password=

An example of these settings is already prepared in comments in the application.properties.

The property spring.profiles.active must be set to jpa.

Please make sure, that the database, referenced by spring.datasource.url, exists in your PostgreSQL database (in this example fa3st-registry).

Please make sure, that you add username and password of your PostgreSQL database in this section (properties spring.datasource.username and spring.datasource.password).