# Setting up Oracle GoldenGate
To set up Oracle GoldenGate using Amazon RDS, configure the hub on an Amazon EC2 instance, and then configure the source and target databases. The following sections give an example of how to set up Oracle GoldenGate for use with Amazon RDS for Oracle.
**Topics**
+ [Setting up an Oracle GoldenGate hub on Amazon EC2](#Appendix.OracleGoldenGate.Hub)
+ [Setting up a source database for use with Oracle GoldenGate on Amazon RDS](#Appendix.OracleGoldenGate.Source)
+ [Setting up a target database for use with Oracle GoldenGate on Amazon RDS](#Appendix.OracleGoldenGate.Target)
## Setting up an Oracle GoldenGate hub on Amazon EC2
To create an Oracle GoldenGate hub on an Amazon EC2 instance, you first create an Amazon EC2 instance with a full client installation of Oracle RDBMS. The Amazon EC2 instance must also have Oracle GoldenGate software installed. The Oracle GoldenGate software versions depend on the source and target database versions. For more information about installing Oracle GoldenGate, see the [Oracle GoldenGate documentation](https://docs.oracle.com/en/middleware/goldengate/core/index.html).
The Amazon EC2 instance that serves as the Oracle GoldenGate hub stores and processes the transaction information from the source database into trail files. To support this process, make sure that you meet the following requirements:
+ You have allocated enough storage for the trail files.
+ The Amazon EC2 instance has enough processing power to manage the amount of data.
+ The EC2 instance has enough memory to store the transaction information before it's written to the trail file.
**To set up an Oracle GoldenGate classic architecture hub on an Amazon EC2 instance**
1. Create subdirectories in the Oracle GoldenGate directory.
In the Amazon EC2 command line shell, start `ggsci`, the Oracle GoldenGate command interpreter. The `CREATE SUBDIRS` command creates subdirectories under the `/gg` directory for parameter, report, and checkpoint files.
```
prompt$ cd /gg
prompt$ ./ggsci
GGSCI> CREATE SUBDIRS
```
1. Configure the `mgr.prm` file.
The following example adds lines to the `$GGHOME/dirprm/mgr.prm` file.
```
PORT 8199
PurgeOldExtracts ./dirdat/*, UseCheckpoints, MINKEEPDAYS 5
```
1. Start the manager.
The following example starts `ggsci` and runs the `start mgr` command.
```
GGSCI> start mgr
```
The Oracle GoldenGate hub is now ready for use.
## Setting up a source database for use with Oracle GoldenGate on Amazon RDS
Complete the following tasks to set up a source database for use with Oracle GoldenGate.
**Topics**
+ [Step 1: Turn on supplemental logging on the source database](#Appendix.OracleGoldenGate.Source.Logging)
+ [Step 2: Set the ENABLE\$1GOLDENGATE\$1REPLICATION initialization parameter to true](#Appendix.OracleGoldenGate.Source.enable-gg-rep)
+ [Step 3: Set the log retention period on the source database](#Appendix.OracleGoldenGate.Source.Retention)
+ [Step 4: Create an Oracle GoldenGate user account on the source database](#Appendix.OracleGoldenGate.Source.Account)
+ [Step 5: Grant user account privileges on the source database](#Appendix.OracleGoldenGate.Source.Privileges)
+ [Step 6: Add a TNS alias for the source database](#Appendix.OracleGoldenGate.Source.TNS)
### Step 1: Turn on supplemental logging on the source database
To turn on the minimum database-level supplemental logging, run the following PL/SQL procedure:
```
EXEC rdsadmin.rdsadmin_util.alter_supplemental_logging(p_action => 'ADD')
```
### Step 2: Set the ENABLE\$1GOLDENGATE\$1REPLICATION initialization parameter to true
When you set the `ENABLE_GOLDENGATE_REPLICATION` initialization parameter to `true`, it allows database services to support logical replication. If your source database is on an Amazon RDS DB instance, make sure that you have a parameter group assigned to the DB instance with the `ENABLE_GOLDENGATE_REPLICATION` initialization parameter set to `true`. For more information about the `ENABLE_GOLDENGATE_REPLICATION` initialization parameter, see the [Oracle Database documentation](https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/ENABLE_GOLDENGATE_REPLICATION.html).
### Step 3: Set the log retention period on the source database
Make sure that you configure the source database to retain archived redo logs. Consider the following guidelines:
+ Specify the duration for log retention in hours. The minimum value is one hour.
+ Set the duration to exceed any potential downtime of the source DB instance, any potential period of communication, and any potential period of networking issues for the source instance. Such a duration lets Oracle GoldenGate recover logs from the source instance as needed.
+ Ensure that you have sufficient storage on your instance for the files.
For example, set the retention period for archived redo logs to 24 hours.
```
EXEC rdsadmin.rdsadmin_util.set_configuration('archivelog retention hours',24)
```
If you don't have log retention enabled, or if the retention value is too small, you receive an error message similar to the following.
```
2022-03-06 06:17:27 ERROR OGG-00446 error 2 (No such file or directory)
opening redo log /rdsdbdata/db/GGTEST3_A/onlinelog/o1_mf_2_9k4bp1n6_.log for sequence 1306
Not able to establish initial position for begin time 2022-03-06 06:16:55.
```
Because your DB instance retains your archived redo logs, make sure that you have sufficient space for the files. To see how much space you have used in the last *num\$1hours* hours, run the following query, replacing *num\$1hours* with the number of hours.
```
SELECT SUM(BLOCKS * BLOCK_SIZE) BYTES FROM V$ARCHIVED_LOG
WHERE NEXT_TIME>=SYSDATE-num_hours/24 AND DEST_ID=1;
```
### Step 4: Create an Oracle GoldenGate user account on the source database
Oracle GoldenGate runs as a database user and requires the appropriate database privileges to access the redo and archived redo logs for the source database. To provide these, create a user account on the source database. For more information about the permissions for an Oracle GoldenGate user account, see the [Oracle documentation](https://docs.oracle.com/en/middleware/goldengate/core/19.1/oracle-db/establishing-oracle-goldengate-credentials.html#GUID-79122058-27B0-4FB6-B3DC-B7D1B67EB053).
The following statements create a user account named `oggadm1`.
```
CREATE TABLESPACE administrator;
CREATE USER oggadm1 IDENTIFIED BY "password"
DEFAULT TABLESPACE ADMINISTRATOR TEMPORARY TABLESPACE TEMP;
ALTER USER oggadm1 QUOTA UNLIMITED ON administrator;
```
**Note**
Specify a password other than the prompt shown here as a security best practice.
### Step 5: Grant user account privileges on the source database
In this task, you grant necessary account privileges for database users on your source database.
**To grant account privileges on the source database**
1. Grant the necessary privileges to the Oracle GoldenGate user account using the SQL command `grant` and the `rdsadmin.rdsadmin_util` procedure `grant_sys_object`. The following statements grant privileges to a user named `oggadm1`.
```
GRANT CREATE SESSION, ALTER SESSION TO oggadm1;
GRANT RESOURCE TO oggadm1;
GRANT SELECT ANY DICTIONARY TO oggadm1;
GRANT FLASHBACK ANY TABLE TO oggadm1;
GRANT SELECT ANY TABLE TO oggadm1;
GRANT SELECT_CATALOG_ROLE TO rds_master_user_name WITH ADMIN OPTION;
EXEC rdsadmin.rdsadmin_util.grant_sys_object ('DBA_CLUSTERS', 'OGGADM1');
GRANT EXECUTE ON DBMS_FLASHBACK TO oggadm1;
GRANT SELECT ON SYS.V_$DATABASE TO oggadm1;
GRANT ALTER ANY TABLE TO oggadm1;
```
1. Grant the privileges needed by a user account to be an Oracle GoldenGate administrator. Run the following PL/SQL program.
```
EXEC rdsadmin.rdsadmin_dbms_goldengate_auth.grant_admin_privilege (
grantee => 'OGGADM1',
privilege_type => 'capture',
grant_select_privileges => true,
do_grants => TRUE);
```
To revoke privileges, use the procedure `revoke_admin_privilege` in the same package.
### Step 6: Add a TNS alias for the source database
Add the following entry to `$ORACLE_HOME/network/admin/tnsnames.ora` in the Oracle home to be used by the `EXTRACT` process. For more information on the `tnsnames.ora` file, see the [Oracle documentation](https://docs.oracle.com/en/database/oracle/oracle-database/19/netrf/local-naming-parameters-in-tns-ora-file.html#GUID-7F967CE5-5498-427C-9390-4A5C6767ADAA).
```
OGGSOURCE=
(DESCRIPTION=
(ENABLE=BROKEN)
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=TCP)(HOST=goldengate-source.abcdef12345.us-west-2.rds.amazonaws.com)(PORT=8200)))
(CONNECT_DATA=(SERVICE_NAME=ORCL))
)
```
## Setting up a target database for use with Oracle GoldenGate on Amazon RDS
In this task, you set up a target DB instance for use with Oracle GoldenGate.
**Topics**
+ [Step 1: Set the ENABLE\$1GOLDENGATE\$1REPLICATION initialization parameter to true](#Appendix.OracleGoldenGate.Target.enable-gg-rep)
+ [Step 2: Create an Oracle GoldenGate user account on the target database](#Appendix.OracleGoldenGate.Target.User)
+ [Step 3: Grant account privileges on the target database](#Appendix.OracleGoldenGate.Target.Privileges)
+ [Step 4: Add a TNS alias for the target database](#Appendix.OracleGoldenGate.Target.TNS)
### Step 1: Set the ENABLE\$1GOLDENGATE\$1REPLICATION initialization parameter to true
When you set the `ENABLE_GOLDENGATE_REPLICATION` initialization parameter is to `true`, it allows database services to support logical replication. If your source database is on an Amazon RDS DB instance, make sure that you have a parameter group assigned to the DB instance with the `ENABLE_GOLDENGATE_REPLICATION` initialization parameter set to `true`. For more information about the `ENABLE_GOLDENGATE_REPLICATION` initialization parameter, see the [Oracle Database documentation](https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/ENABLE_GOLDENGATE_REPLICATION.html).
### Step 2: Create an Oracle GoldenGate user account on the target database
Oracle GoldenGate runs as a database user and requires the appropriate database privileges. To make sure it has these privileges, create a user account on the target database.
The following statement creates a user named `oggadm1`.
```
CREATE TABLESPSACE administrator;
CREATE USER oggadm1 IDENTIFIED BY "password"
DEFAULT TABLESPACE administrator
TEMPORARY TABLESPACE temp;
ALTER USER oggadm1 QUOTA UNLIMITED ON administrator;
```
**Note**
Specify a password other than the prompt shown here as a security best practice.
### Step 3: Grant account privileges on the target database
In this task, you grant necessary account privileges for database users on your target database.
**To grant account privileges on the target database**
1. Grant necessary privileges to the Oracle GoldenGate user account on the target database. In the following example, you grant privileges to `oggadm1`.
```
GRANT CREATE SESSION TO oggadm1;
GRANT ALTER SESSION TO oggadm1;
GRANT CREATE CLUSTER TO oggadm1;
GRANT CREATE INDEXTYPE TO oggadm1;
GRANT CREATE OPERATOR TO oggadm1;
GRANT CREATE PROCEDURE TO oggadm1;
GRANT CREATE SEQUENCE TO oggadm1;
GRANT CREATE TABLE TO oggadm1;
GRANT CREATE TRIGGER TO oggadm1;
GRANT CREATE TYPE TO oggadm1;
GRANT SELECT ANY DICTIONARY TO oggadm1;
GRANT CREATE ANY TABLE TO oggadm1;
GRANT ALTER ANY TABLE TO oggadm1;
GRANT LOCK ANY TABLE TO oggadm1;
GRANT SELECT ANY TABLE TO oggadm1;
GRANT INSERT ANY TABLE TO oggadm1;
GRANT UPDATE ANY TABLE TO oggadm1;
GRANT DELETE ANY TABLE TO oggadm1;
```
1. Grant the privileges needed by a user account to be an Oracle GoldenGate administrator. Run the following PL/SQL program.
```
EXEC rdsadmin.rdsadmin_dbms_goldengate_auth.grant_admin_privilege (
grantee => 'OGGADM1',
privilege_type => 'apply',
grant_select_privileges => true,
do_grants => TRUE);
```
To revoke privileges, use the procedure `revoke_admin_privilege` in the same package.
### Step 4: Add a TNS alias for the target database
Add the following entry to `$ORACLE_HOME/network/admin/tnsnames.ora` in the Oracle home to be used by the `REPLICAT` process. For Oracle Multitenant databases, make sure that the TNS alias points to the service name of the PDB. For more information on the `tnsnames.ora` file, see the [Oracle documentation](https://docs.oracle.com/en/database/oracle/oracle-database/19/netrf/local-naming-parameters-in-tns-ora-file.html#GUID-7F967CE5-5498-427C-9390-4A5C6767ADAA).
```
OGGTARGET=
(DESCRIPTION=
(ENABLE=BROKEN)
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=TCP)(HOST=goldengate-target.abcdef12345.us-west-2.rds.amazonaws.com)(PORT=8200)))
(CONNECT_DATA=(SERVICE_NAME=ORCL))
)
```