Configuring Persistence

Configuration

Atoti Limits provides a set of services that allow you to manage objects that exist within the application at runtime.

Managed objects

Atoti Limits manages three types of objects:

1. Limit Structures
2. Limits
3. Incidents

These objects may be loaded from an external database, where they can be managed from within Atoti Limits and any changes will be propagated to the external database of choice.

To work with persistent data in Atoti Limits, you need to specify the load mode and configure the connection to the external datasource.

1. Specifying the load mode

You can specify one of three modes when loading data into Atoti Limits:

1. CSV
2. PERSISTENT
3. CSV_TO_PERSISTENT

CSV load mode

This is the default load mode for Atoti Limits. In this mode, data is loaded from CSV files, similar to previous versions of Atoti Limits. You don’t need to configure the external datasource in this mode. You don’t need to explicitly enable this mode, however it can be done so by setting the property limits.data.mode=csv.

Persistent load mode

This is the load mode required to work with persistent data in Atoti Limits. In this mode, data is loaded from an external database using JPA (Java Persistence API), specifically Spring’s Data JPA. To use this load mode:

1. Enable it by setting the property limits.data.mode=persistent
2. Configure the external datasource

2. Configuring the external datasource

Generating the DDLs

To generate the DDL (Data Definition Language) for any of the datasources, use Spring properties. For example, to generate the DDLs for the limits-application datasource, you can set the following properties:

limits:  
    application:
        datasource:
          url: "your-url"
          username: your-username
          password: your-password
          properties:
            jakarta:
              persistence:
                schema-generation:
                  create-source: metadata
                  drop-source: metadata
                  scripts:
                    action: drop-and-create
                    create-target: create-limits.sql
                    drop-target: drop-limits.sql

Once you start Atoti Limits this will generate two files, create-limits.sql and drop-limits.sql, in the root directory of the server project. If you are not using Liquibase, the DDL can then be used to create your database.

Configuring the connection to the external datasource

The connection to an external datasource is configured using properties. The default properties are as follows:

limits:
  application:
    datasource:
      url: "jdbc:h2:mem:limits-application;DB_CLOSE_DELAY=-1;"
      username: app
      password:
      properties:
        hibernate:
          dialect: org.hibernate.dialect.H2Dialect
          format_sql: true
          hbm2ddl:
            auto: update
          globally_quoted_identifiers: true
      hikari:
        connectionTimeout: 30000
        idleTimeout: 60000
        minimumIdle: 1
        maximumPoolSize: 10
        poolName: "limits-application"

Let’s discuss some of these in more detail:

• The properties are prefixed by limits.application.datasource. This follows the Spring Boot convention for configuring datasources and is what we expect when the datasources are configured in LimitsJpaConfig.java.

• The url property specifies the JDBC URL for the database. In this case, we are using an in-memory H2 database named limits-application.

  warning

  This is not recommended in production. H2 is only intended for development purposes and is not a production grade database. We expect users to use another database. See the MSSQL example for an example of how to configure a connection to a Microsoft SQL Server database.

• The hibernate.hbm2ddl.auto property specifies the behavior of the database schema. In this case, we are using update, which means that the schema will be updated based on the entities in the application.

  warning

  This is not recommended in production. We expect users to manage their own database schema.

• The globally_quoted_identifiers property is set to true. This is to escape reserved keywords in the database when defining columns. For example, the LimitStructure field group will be mapped to the column name group, which is a reserved keyword in H2, so we delegate to Hibernate to escape.

For more information on the available properties, please see the Spring documentation.

CSV to Persistent load mode

This mode is used to migrate limits from the CSV sources to the external database. For more information, see Limits Data Migration.

For information on extending persistence in Atoti Limits, see Adding Custom Persistence.