Installation Steps

<Resource name="jdbc/flexdbDS" auth="Container"
    type="oracle.ucp.jdbc.PoolDataSource"
    factory="oracle.ucp.jdbc.PoolDataSourceImpl"

    connectionFactoryClassName="oracle.jdbc.pool.OracleDataSource"
    minPoolSize="0"
    maxPoolSize="100"
    initialPoolSize="0"
    autoCommit="false"

    url="jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=tcp)(HOST=**HOSTNAME**)(PORT=**PORT**)))(CONNECT_DATA=(SERVICE_NAME=**SERVICE_NAME**)))"
    user="fd_admin"
    password="**FD_ADMIN_PASSWORD**"

    fastConnectionFailoverEnabled="true"

    validationQuery="select 1 from dual"
    testOnBorrow="true"

    useLocalSessionState="true"
    defaultAutoCommit="false"/>

Key Points

url="jdbc:oracle:thin:@(DESCRIPTION = CONNECT_TIMEOUT=120) (RETRY_COUNT=20) (RETRY_DELAY=3) (TRANSPORT_CONNECT_TIMEOUT=3) (ADDRESS_LIST =(LOAD_BALANCE=on) (ADDRESS = (PROTOCOL = TCP) (HOST=primary-scan) (PORT=1521))) (ADDRESS_LIST =(LOAD_BALANCE=on) (ADDRESS = (PROTOCOL = TCP) (HOST=secondary-scan) (PORT=1521))) (CONNECT_DATA=(SERVICE_NAME = gold-cloud)))"

References