• The primary database and all True Caches in the GDS pool must be able to reach (in both directions) every global service manager’s (GSM's) listener and Oracle Notification Service (ONS) ports. The GSM listener ports and ONS ports must also be opened to the application tier, the primary database and all True Caches in the GDS pool, the GDS catalog, and all other GSMs.
• The TNS listener port (default: 1521) of the primary database and all True Caches in the GDS pool must be opened (in both directions) to the GSMs and the GDS catalog.
• If you run GDSCTL from a separate machine, you also must have a port opened (in both directions) from that machine directly to the primary database and all True Caches in the GDS pool.

For detailed information about memory, physical storage, kernel versions and packages required by Global Data Services see Database Installation Guide for Linux.

Install at least one GSM in each region. For high availability, include two GSMs in each region.

To install GSMs, see the following topics in the Oracle Database Global Data Services Concepts and Administration Guide:

• What You Need to Know About Installing a Global Service Manager
• Installing a Global Service Manager

For Oracle DBCA:

1. Prerequisites
2. Creating True Cache with DBCA

For a manual configuration:

1. Prerequisites
2. Creating True Cache Manually

1. Create the GDS administrator account and grant GSMADMIN_ROLE privileges.

   For example:

   CREATE USER gsm_admin IDENTIFIED BY ****

   GRANT gsmadmin_role TO gsm_admin

2. Unlock the GDS system accounts on the catalog database.

   sqlplus / as SYSDBA

   ALTER USER gsmuser ACCOUNT UNLOCK IDENTIFIED BY ****

   ALTER USER gsmcatuser ACCOUNT UNLOCK IDENTIFIED BY ****

3. Start GDSCTL.

   gdsctl

For large-scale GDS configurations, Oracle recommends that the GDS catalog be hosted outside the databases in the GDS configuration.

create catalog -database db_name –region region_list -user user_name/password

For example:

create catalog -database gdscatdb -region DCX, DC_Y -user gsmcatuser/****

If you don't specify a region when setting up the catalog, then a default region named REGIONORA is created. You can optionally add more regions later.

For high availability, include two GSMs in each region.

1. Add a GSM to the region.

   add gsm -gsm gsm_name -pwd password -catalog catalog_db_name -region region_name

   For example:

   add gsm -gsm gsm_dc_x1 -catalog primdb1i -pwd **** -region DC_X

   Note:

   You can run this command only on the system that hosts the GSM. Repeat the command for each GSM on each system that runs the GSM.

2. Start the GSM.

   start gsm -gsm gsm_name

   For example:

   start gsm -gsm gsm_dc_x1

3. Check the status of the GSM.

   status gsm

For high availability, assign a buddy region for each region. Only one buddy region is allowed for each region.

add region –region region_list

modify region -region region_name -buddy region_name

For example:

add region -region DC_X, DC_Y

modify region -region DC_X -buddy DC_Y

add gdspool -gdspool db_pool_list

add database -connect db_name -region region_name -gdspool gds_pool_name

For example:

add gdspool -gdspool sales

add database -connect primdb1i -pwd **** -gdspool sales –region DC_X  // primary

add database -connect tcdb1 -pwd **** -gdspool sales –region DC_X  // True Cache

1. Create the global services for the primary database.

   add service -service service_name.domain_name -gdspool gdspool_name -preferred dbname_list -pdbname primary_pdb_name -role primary

   For example:

   add service -service sales.example.com -gdspool sales -preferred primdb1i -pdbname sales_pdb -role primary

2. Create the global services for True Cache.

   add service -service service_name.domain_name -gdspool gdspool_name -preferred_all -pdbname primary_pdb_name -clbgoal SHORT –rlbgoal SERVICE_TIME –locality LOCAL_ONLY –region_failover -lag lag_value -role true_cache -failover_primary

   For example:

   add service -service sales_tc.example.com -gdspool sales -preferred_all -pdbname sales_pdb -clbgoal SHORT –rlbgoal SERVICE_TIME –locality LOCAL_ONLY –region_failover -lag 15 -role true_cache -failover_primary

   Note:

   The -failover_primary option requires the patch for bug 36740927.

3. Associate the True Cache service with the primary database service.

   • For True Cache and single instance primary databases, use the DBMS_SERVICE_PRVT PL/SQL package.

     On the primary database, connect to the PDB first. The following example uses the sales.example.com and sales_tc.example.com services.

     ALTER SESSION SET CONTAINER=primary_pdb_name;

     DECLARE
         db_params sys.dbms_service_prvt.svc_parameter_array;
         cl_params sys.dbms_service_prvt.svc_parameter_array;
     BEGIN
         -- modify an already existing primary service SALES to set the TRUE_CACHE_SERVICE attribute and associate with SALES_TC
         db_params('true_cache_service') :='sales_tc.example.com';
         DBMS_SERVICE_PRVT.MODIFY_SERVICE('sales.example.com', cl_params, db_params, FALSE, 1);
     END;

   • For Oracle RAC primary databases, use the srvctl command line utility with the -global_override option to alter global services.

     If you configure True Cache with Oracle DBCA, use the following command:

     srvctl add service -db primary_db_unique_name -service primary_db_service_name.domain_name -preferred primary_db_instance_list -pdb primary_pdb_name -global_override

     For example:

     srvctl add service -db primdb1i -service sales.example.com -preferred primdb1i1,primdb1i2 -pdb sales_pdb -global_override

     For manual configuration options, see Create Database Application Services on the Primary Database.

     Note:

     Also disable the True Cache service on the cluster where it was added to prevent errors when stopping and restarting the primary database services. For example:

     srvctl start service -d primdb1i -s sales_tc.example.com

     srvctl stop service -d primdb1i -s sales_tc.example.com

     srvctl disable service -d primdb1i -s sales_tc.example.com

     This doesn't affect standby databases or True Caches because they run outside the cluster where the True Cache service is disabled. The disabled status is not stored in the primary dictionary and DBA_SERVICES, but only in Cluster Ready Services (CRS), and only in the cluster where the True Cache service was added. Other databases outside the cluster can start the service with DBMS_SERVICE.START_SERVICE and aren't affected by this setting.

4. Start the services.

   start service -service service_name.domain_name

   The following example starts the services on the primary database and on all True Caches:

   start service -service sales.example.com

   start service -service sales_tc.example.com