ORA-12505 error with oracle 11.2.0.2 RAC Grid

Question

Hi,
We have just installed Oracle 11.2.0.2 with oracle clusterware. Every thing went well during the installation, How ever after install we can not connect to the RAC instance from clients, through jdbc OR oracle sql developer.
We get following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor.
After the installation we created service (myrac) through OEM Cluster Managed Database Services tab. and We are using service name as following:
jdbc:oracle:thin:@orap-cluster.mydomain.com:1521:myrac
Here below is Service TNS string:
myrac = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = orap-cluster.mydomain.com)(PORT = 1521))(LOAD_BALANCE = YES)(CONNECT_DATA = (SERVER = DEDICATED)(SERVICE_NAME = myrac)))
Any help..??
Cheers

Answer 1

HI,
to clarify:
if you try with
<SERVER>:<PORT>:<SID> you are accessing the server with a database SID, whereas
<SERVER>:<PORT>/<SERVICE> will access a service.
The SCAN Listener only know of services, and not of database SIDs.
This is the reason you should always create separate services for your RAC databases, since only they are registered. If you connect via. a service the listener will forward you to (one of) the corresponding instances servicing the service.
Database SIDs are only known to the local listener on the node (not to the SCAN listener). And SIDs actually should not be used anymore.
However if you still need to access the SID you can use the virtual hostname of the server resp. the VIP address of the server in the connection and this will work:
<VIP>:<PORT>:<SID>
Note the SID of a RAC database is either myrac1 or myrac_1 (depending on administrator or policy managed database).
I still would recommend using services and not SIDs.
Furthermore the SCAN can only be resolved correctly by 11.2 clients.
Any pre 11.2 client should use an address_list containing the SCAN VIPs:
PRE112 =
(DESCRIPTION =
(LOAD_BALANCE=ON)
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.41)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.42)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.43)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = pre112)
If a application server does not understand / then try using the TNSNAMES entry directly:
jdbc:oracle:thin:@(DESCRIPTION = (LOAD_BALANCE=ON)(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.41)(PORT = 1521))(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.42)(PORT = 1521))(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.43)(PORT = 1521))(CONNECT_DATA = (SERVER = DEDICATED)(SERVICE_NAME = pre112)))
Hope that helps
Regards
Sebastian