Hello, Ask Tom Team.

We have a two-node RAC running a database. The app connects to the database using scan name (best practice), so we are not using vip to connect to database directly. The tnsnames.ora is:

DBPROD =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = scanprod.domain.local)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = dbprod) --default database service
)
)

We recently had an issue with instance 1, Oracle Support was patching node 1 and instance was not starting (it stuck at "STARTING"), it never came up. But the RAC was thinking node 1 was good, so it redirect connections to node 1 when using scan. Then, we got errors like: "shutdown or initialization in progress". All apps using tnsnames above, were not connecting to database.

When Oracle Support shutdown node 1 to patch it, we had a service pointing to node 1 and it automatically moved to instance 2 but the apps pointing to default service, never got connected to db.


DBPROD =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = scanprod.domain.local)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = myservice1)
)
)


1. Do you recommend using this configuration (connect using the default database service when you create the database) or create new services pointing to preferred instances with its available failover instance?