nested exception is java.sql.SQLException: Io exception: NL Exception was genera

Question:  I'm trying to connect to multiple Oracle 10g databases (failover) over the JDBC thin client, and when I run the following, I get:

java.sql.SQLException: Io exception: NL Exception was generated

connection = DriverManager.getConnection("jdbc:oracle:thin:@DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP) (HOST = dbdev) (PORT = 1521))) (CONNECT_DATA = (INSTANCE_NAME = orcldev)))", "scott", "tiger");

I eventually want to put multiple addresses in that string.  Right now I'm trying to get it to work with one! I've tried multiple variations of this and using the internal IP address for the HOST dbdev (see below). Here's the tnsnames.ora file used by SQL*Plus on the same client machine that the NL Exception Error in RZC is occurring:

ORCLDEV.world =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.132)(PORT = 1521))
(CONNECT_DATA =
(SID = orcldev)
)
)

Answer:  Try This to solve your oracle NL Exception error on 10g RAC:

jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)))(HOST=host
)(PORT=port)
(CONNECT_DATA=(SERVICE_NAME=sid)(SERVER=DEDICATED))

Adding SERVER=DEDICATED should clear up this NL Exception error (see below)



MOSC Note:139775.1 has information available on the oracle NL Exception error:


"To verify whether you are hitting this problem, verify whether the
Oracle instance is configured for Multithreaded Server (MTS).
If the Oracle instance is not configured for MTS, you are probably
encountering a different problem. Otherwise, continue."



MOSC goes on about the NL Exception error:

"To understand why this problem occurs, one must first understand the differences in how the listener handles connections to shared servers versus dedicated servers."

MOSC also goes on to describe the solutions to an NL Exception error:

"Obviously, one solution is to use dedicated servers. However, this
may not always be feasible. The key is to make sure the hostname on both the client and server agree."