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Don Burleson Blog 







ORA-30683: failure establishing connection to debugger tips

Oracle Database Tips by Donald BurlesonApril 15, 2015

We are getting the ORA-30683 error when attempting to connect via SQL Developer:

Connecting to the database TEST.
Executing PL/SQL: CALL DBMS_DEBUG_JDWP.CONNECT_TCP( '****', '4000' )
ORA-30683: failure establishing connection to debugger
ORA-12535: TNS:operation timed out

What is the fix for this ORA-30683 error?

Answer:   The oerr command shows this for the ORA-30683 error:

ORA-30683: failure establishing connection to debugger

Cause: An error was indicated when trying to establish a connection to a debugger. Usually a TNS error will display along with this message to further explain the problem, although this TNS error will likely be hidden if you choose to trap the error. In your case you also get the ORA-12535 operation timed out error.

Action: Correct the indicated parameter value and try again.

First, make sure all the ports set in the PL/SQL Debugging Options page can be opened for external access. 

1 - You could have a firewall issue.  The SQL Debugger by default uses ports 40000 to 49000. If you cannot get the debugger to start, make sure that you are not being blocked by a firewall on these ports.  Test by turning-off software firewall or define SQL Developer to a specific port number.

2 - Change SQL Developer preferences.

From main menu-->'Tools --> preferences --> debugger'

Check the box titled  'Prompt for debugger host for database debugging'.
With this option SQL Developer ask the IP address where it is installed; this should resolve ORA-30683 errors if you are using TNS connection ;


3 - Ensure that the hostname (or IP address) are in this line

Executing PL/SQL: CALL DBMS_DEBUG_JDWP.CONNECT_TCP( 'hostname', '4000' )

Note: You may need to use a hostname instead of an IP address to fix the ORA-30683 error.

4 - Missing privileges:


5 - Your listener process is not running or it not accepting connections.  Issue the lsnrctl start command.

6 - Make sure that you are not using shared servers (the multi-threaded server)

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