Configuring the CDC Replication Engine for Oracle databases instances for local log reading

You can configure CDC Replication Engine for Oracle databases to use Oracle archive and redo logs that reside locally to the database.

About this task

By default, the product is configured to read both online redo log files and archived log files. This provides for low latency replication as the online log is continuously written by Oracle and read by the CDC Replication Engine for Oracle databases log reader. However, the product can also be configured for reading archive log files only.

Procedure

  1. If you are configuring the first instance of the CDC Replication Engine for Oracle databases after installation, you can proceed to Step 4 of this procedure.
  2. At the command prompt, launch the configuration tool by issuing the following command in the specified directory: 
    \CDC_installation_directory\bin\dmconfigurets
  3. If you are configuring instances subsequent to the first instance, enter 2 and press Enter.

    Proceed to Step 5 of this procedure.

  4. At the welcome message, press Enter to continue.
  5. Enter the name of the instance that you want to add and press Enter.

    The instance name must be unique.

  6. Enter the port number which CDC Replication uses for communication with client workstations running Management Console and other servers. CDC Replication displays a default port of 11001. Press Enter.

    This port number is not applicable for other applications installed on the same server. You will use this port number when specifying access parameters for your datastore in the Access Manager perspective in Management Console.

  7. Enter the maximum amount of disk space that will be utilized by the CDC Replication staging store on your source system. The default value is 100 GB.

    Specify 1 GB if you are creating an instance that will be used as a target of replication. This reduces the disk resources that CDC Replication requires on your target system.

  8. Enter the amount of physically available RAM that you want to allocate for this instance of CDC Replication and press Enter. By default, the configuration tool allocates 1024 MB of RAM for each instance.

    Using values other than the defaults or allocating more RAM than is physically available on your server should only be undertaken after considering the impacts on product performance.

  9. Select the encryption profile from the list.
    If you would like to enable TLS for communication between source and target, you must select an encryption profile with encryption enabled. Click Manage to view and manage the available encryption profiles. Encryption profiles can be shared between multiple instances of CDC Replication.
  10. If you have configured a read-only connection to the Oracle database, then enter y. For Oracle databases with read and write access, enter n.

    Once you have created an instance of CDC Replication with a connection to a read-only database, then this option is set and you cannot connect to the Oracle database with read and write access.

  11. If you want the CDC Replication Engine for Oracle databases to read only archived logs, enter y and press Enter.
  12. If you want to use TCP/IP as the exclusive method of communication between datastores, enter n and press Enter. If you want to have the option to use either a JMS provider or TCP/IP as the communications protocol, perform the following steps:

    A JMS provider should be used when characteristics of your network prevent the existence of a long-term, stable TCP/IP connection.

    1. Ensure that a queue has been created by your system administrator and is named correctly. Each CDC Replication instance that is to use a JMS message provider must have a queue named in the format CDC_<port>, where <port> is the five digit TCP listening port number of the instance. You can left-pad the number with zeroes if necessary to ensure five digits (example, CDC_00123).
    2. Enter y and press Enter.
    3. Enter 2 to add a JMS provider.
    4. Enter the fully qualified path to your JMS provider .jar file and press Enter.
    5. Enter 4 and press Enter to complete the configuration of the JMS providers.
    6. Enter 1 to add a JMS connection.
    7. Enter a JMS remote connection factory name and press Enter. For example, jms/ConnectionFactory. A connection factory encapsulates a set of connection configuration parameters that has been defined by an administrator. CDC Replication uses this to create a connection with your JMS provider.
    8. Enter the user name and press Enter.
    9. Enter the password to authenticate to the JMS server and press Enter.
    10. Enter the password a second time to confirm and press Enter.
    11. Enter the JNDI initial context and press Enter.
    12. Enter the URL that is relative to the JNDI Initial Context and press Enter.
    13. Enter the user name for the JNDI Principal and press Enter.
    14. Enter the JNDI credentials password and press Enter.
    15. Enter the password a second time to confirm and press Enter.
    16. Press Enter again to return to the Engine Communication Connection menu.
    17. Press 5 if you want to verify the connection and then press Enter to return to the Engine Communication Connection menu.

      If the JMS Provider is not configured correctly, CDC Replication will use TCP/IP as the communication protocol between datastores.

    18. Enter 7 to complete the configuration of the engine communication connection.
  13. Enter the path of the Oracle database (ORACLE_HOME environment variable) you want to replicate data to or from and contains all of the tables for replication. This is the database that you configured as part of the preinstallation tasks. Press Enter.

    If you are configuring an instance for an Oracle RAC environment, consider the following:

    • If you are using Oracle ASM to manage your Oracle redo log files, select the Oracle SID of the local node where CDC Replication is installed. Additional ASM information is required in step 20 of this procedure.
    • If you are not using Oracle ASM to manage your Oracle redo log files, select the Oracle global service name that you defined for CDC Replication in the tnsnames.ora file.
  14. Enter the number that corresponds to the TNS name for your Oracle database that you defined for CDC Replication in the tnsnames.ora file and press Enter.
  15. If you want to specify extra JDBC parameters, perform the following steps. Otherwise, enter n and press Enter.
    1. Enter y and press Enter.
    2. Enter the extra JDBC parameters in a semicolon delimited list and press Enter.
  16. At the prompt Use kerberos authentication (y/n), specify the authentication method for the database. Choose one of these options:
    Authentication method Steps
    Kerberos Choose whether to use Kerberos authentication (y) or not (n):
    y
    Enter y and press Enter.

    You are prompted to enter any additional JVM parameters to enable Kerberos authentication. The following example shows a JVM parameter that you might be prompted to enter:

    -Djava.security.auth.login.config=JAAS-conf-file-location

    The JAAS-conf-file-location must have the following format:

    JDBC_DRIVER_01 {
com.ibm.security.auth.module.Krb5LoginModule required
useDefaultCcache=true
credsType=both
useKeytab="/IIDRForOracle/krboracle.tab"
principal="krboracle@KERBEROS.DOMAIN.COM";
};

    JDBC_DRIVER_01 is the required entry name. Because the CDC Replication Engine for Oracle databases bundles the IBM® JVM with the product, the parameter and format must follow IBM Java™ format.

    n
    Enter n to specify that you do not want to use Kerberos authentication, then press Enter.
    External secret store through Java user exit Choose whether to use an external secret through Java user exit authentication (y) or not (n):
    y
    1. Enter y and press Enter. You are prompted to enter the Java class name of the external secret store user exit, for example com.datamirror.ts.external.keystore.VaultExternalSecretStoreTest.
    2. Enter the case-sensitive database user key from external secret store for the specified database and press Enter.
    3. Enter the case-sensitive database password key from external secret store for the specified database and press Enter.

    See Creating an instance by using database credentials stored in an external secret store for more details.

    n
    Specifies to not use an external secret store.
    User name and password
    1. Enter n and press Enter.
    2. Enter the user name for the specified database and press Enter. If you configured an Oracle database with a read-only connection, specify the read-only user for that database.
    3. Enter the case-sensitive password for the specified database and press Enter.
    After you select and configure the authentication method, the configuration tool searches the database for schemas.
  17. Enter the number that corresponds to the database schema used by CDC Replication for metadata tables and press Enter. You can specify any schema except those in use by other installed instances of CDC Replication for the given database.

    If the number of detected schemas is large, you will be offered the option of entering the schema name directly or you can press Enter to view the pages of schema names.

    You will not be asked for this information if you choose a read-only database.

    Note: CDC Replication metadata tables contain important configuration information and should be backed up as part of your database backup strategy.
  18. If you do not want to replicate encrypted columns/tables, enter n and press Enter. If you want to replicate encrypted columns/tables, perform the following steps:
    1. Obtain the Oracle master key from your Oracle DBA. For an Oracle 12c container database, obtain both the root database master key and the pluggable database master key.
    2. Enter y and press Enter.
    3. Enter the Oracle master key and press Enter.
  19. Enter 1 to choose Local log reading as your configuration mode and press Enter.
  20. If you are using ASM exclusively to manage your Oracle redo logs, CDC Replication will detect it automatically and request the following information. If ASM is not being used exclusively, you will be asked if you want to provide ASM connection details. Enter y and press Enter to provide details or enter n and press Enter to continue to the next step.
    1. Enter the path information for the ASM instance (ASM ORACLE_HOME environment variable) that is installed on the local node and press Enter.
    2. Enter the path for the ASM TNSNAMES.ORA file.
    3. Enter the number that corresponds to the TNS name for your ASM Oracle database that you defined for CDC Replication in the tnsnames.ora file and press Enter.

      If the number of detected TNS names is large, you will be offered the option of entering the TNS names directly or you can press Enter to view the pages of TNS names.

    4. Enter your ASM user name and press Enter. If External Secret Store Authentication is selected, enter the ASM user name key.
    5. Enter your ASM password and press Enter. If External Secret Store Authentication is selected, enter the ASM password key.
    6. If you want to specify extra JDBC parameters for ASM, perform the following steps. Otherwise, enter n and press Enter.
      1. Enter y and press Enter.
      2. Enter the extra JDBC parameters separated by semicolons and press Enter.
    7. Linux: Enter the ASM Disk Label path and press Enter.

      If the ASM database uses ASMLib or ASM Filter Driver (AFD) to access the disk groups, you must specify the ASM Disk Label. This label is the disks folder under the path where the ASM manager is mounted, for example ASM_manager_mount_point/disks.

      For assistance in determining your ASM Disk Label path, contact your database administrator.

  21. If CDC Replication detects an unsupported encoding, an error message will be displayed and you will be asked to choose an alternate encoding.
    1. Enter y to proceed.

      If you enter n and press Enter to cancel, the instance will not be created.

    2. Enter a value to choose how the alternate encodings will be displayed:
      1
      Displays the available alternate encodings that are the closest match to the database.
      2
      Displays the available alternate encodings in order of byte length.
      3
      Displays all available alternate encodings.
    3. Enter the number for the encoding to be used and press Enter.
  22. The configuration tool creates the CDC Replication instance and prompts you to start the instance. Enter y to start the instance.

    The configuration tool will prompt you if your configuration is about to overwrite the metadata for an existing instance.