Connecting to GDS Configuration Databases When No Global Service Managers Are Running

Troubleshoot GSM by using three address lists: regional GSM, buddy GSM, and then the local/SCAN; fall back only if GSM is down.

When troubleshooting GSM connectivity, check the configuration and connect using your region's GSM listeners first. This first list should be exclusively regional global service manager listeners. The second list contains global service manager listeners of the buddy region. The third list should be your local or SCAN listeners. With these three lists, connections use GSM when it's available and only fall back to local listeners if all GSM listeners are down.

You can always connect through a global service manager while it is up, and only fail over to local listeners when all global service manager listeners are down.

Template

Use this template as a model.

(DESCRIPTION=
  (FAILOVER=on)
  (ADDRESS_LIST=
    (LOAD_BALANCE=ON)
    (ADDRESS=(global_protocol_address_information))
    (ADDRESS=(global_protocol_address_information))
    (ADDRESS=(global_protocol_address_information))
   )
  (ADDRESS_LIST=
    (LOAD_BALANCE=ON)
    (ADDRESS=(global_protocol_address_information))
    (ADDRESS=(global_protocol_address_information))
    (ADDRESS=(global_protocol_address_information))
   )
  (ADDRESS_LIST=
    (LOAD_BALANCE=ON)
    (ADDRESS=(local_protocol_address_information))
    (ADDRESS=(local_protocol_address_information))
   )
  (CONNECT_DATA=
   (SERVICE_NAME=global_service_name)
   (REGION=region_name)))

Note that this example uses three address lists, where gsmhost1, gsmhost2 and gsmhost3 are the regional GSMs. gsmhost4, gsmhost5 and gsmhost6 are buddy GSMs. Finally, server1 has the local listener.

(DESCRIPTION=
     (FAILOVER=on)
     (ADDRESS_LIST=
       (LOAD_BALANCE=ON)
       (ADDRESS=(HOST=gsmhost1)(PORT=1523)(PROTOCOL=TCP))
       (ADDRESS=(HOST=gsmhost2)(PORT=1523)(PROTOCOL=TCP))
       (ADDRESS=(HOST=gsmhost3)(PORT=1523)(PROTOCOL=TCP))
      )
     (ADDRESS_LIST=
       (LOAD_BALANCE=ON)
       (ADDRESS=(HOST=gsmhost4)(PORT=1523)(PROTOCOL=TCP))
       (ADDRESS=(HOST=gsmhost5)(PORT=1523)(PROTOCOL=TCP))
       (ADDRESS=(HOST=gsmhost6)(PORT=1523)(PROTOCOL=TCP))
      )
     (ADDRESS_LIST=
       (LOAD_BALANCE=ON)
       (ADDRESS=(HOST=server1)(PORT=1521)(PROTOCOL=TCP))
      )
     (CONNECT_DATA=
      (SERVICE_NAME=sales_read_service.dbpoolora.oradbcloud)
      (REGION=WEST)))

Note:

In the case of an Oracle RAC enabled GDS database, the third address list contains the local Oracle RAC database's SCAN listeners.

Parent topic: Troubleshooting GDS Issues