About Data Sources

The Oracle WebLogic Server domain in an Oracle Java Cloud Service instance is automatically configured with several JDBC data sources. You can customize these data sources and also create additional ones.

Java Database Connectivity (JDBC) data sources in WebLogic Server provide database access and database connection management. Each data source contains a pool of reusable database connections that are created when the data source is created and at server startup. Applications reserve a database connection from the data source and then return it back to the pool when finished using it.

Topics

Predefined Data Sources

When you create an Oracle Java Cloud Service instance you provide the locations of one or more databases in Oracle Cloud.

These databases are used for different purposes:

Infrastructure Schema Database — Oracle Java Cloud Service provisions this Oracle Database or Pluggable Database (PDB) with the required Oracle Fusion Middleware schema and data. By default, this schema is automatically deleted when you delete the service instance.
Application Schema Database (optional; up to 4) — You can provision this Oracle Database or PDB with any business data that your applications require, and using any standard Oracle Database tools. This feature is supported only if you associate the service instance with an Oracle Database Cloud Service deployment. It is not available for other database services.

During the service instance creation process, Oracle Java Cloud Service creates JDBC data sources in the WebLogic Server domain in order to provide connectivity to these databases.

Data Source Types

WebLogic Server provides several types of data sources.

Generic — Connects to a single database node.
Multi — Provides load balancing and failover across a group of Generic data sources.
GridLink — Provides dynamic load balancing and failover across an Oracle Database RAC cluster, and also receives notifications from the cluster when nodes are added or removed. This type of data source can only be used with Oracle Database.

The type of data source that Oracle Java Cloud Service creates in your domain depends on the following:

The Software Edition of your service instance.
Whether or not the selected database is RAC-enabled. See Using Oracle Real Application Clusters (RAC) in Oracle Database Cloud Service.

Software Edition	RAC Database?	Data Source Type
Standard	No	Generic
Standard	Yes	Generic
Enterprise	No	Generic
Enterprise	Yes	Multi
Enterprise with Coherence (Suite)	No	Generic
Enterprise with Coherence (Suite)	Yes	GridLink See Configure an Oracle Java Cloud Service Instance for an Oracle RAC Database.

Custom Data Sources

You can modify and tune the existing data sources that were created by Oracle Java Cloud Service, and you can also create additional data sources in your WebLogic Server domain to provide connectivity to other databases or PDBs.

Create and configure data sources using standard tools like the WebLogic Server Administration Console, Fusion Middleware Control, or WebLogic Scripting Tool (WLST).

For more information on the different types of data sources and how to configure them, refer to Configuring JDBC Data Sources in one of the following publications:

Data Source Network Connectivity

When you create an Oracle Java Cloud Service instance, it is automatically configured with the necessary security rules to enable connectivity to the specified databases.

These rules allow the WebLogic Servers in your service instance to connect to your databases through the Oracle Cloud network. If you create additional data sources in your service instance, and these data sources connect to databases that are running outside of the nodes in your Oracle Java Cloud Service instance, then you must create custom security rules to explicitly permit this database network traffic. Security rules are not required if the database to which you are connecting is running on the nodes in your Oracle Java Cloud Service instance.

For service instances on Oracle Cloud Infrastructure regions, see Security Lists in the Oracle Cloud Infrastructure documentation.
For service instances on Oracle Cloud Infrastructure Classic regions, see Create an Access Rule.