ERROR : Connection was refused with error ORA-12519

Please check MOS id:552765.1


One of the most common reasons for the TNS-12516 and/or TNS-12519 errors being reported is the configured maximum number of PROCESSES and/or SESSIONS limitation being reached. When this occurs, the service handlers for the TNS listener become "Blocked" and no new connections can be made. Once the TNS Listener receives an update from the PMON process associated with the Database instance telling the TNS Listener the thresholds are below the configured limit, and the database is now accepting connections connectivity resumes.

In this case please check v$resource_limt view to find maximum utilization and available utilization.

For this,


Select resource_name,current_utilization,max_utilization ,limit_value from v$resource_limit;

If current utilization reaches the limit then increase the appropriate value, then if necessary bounce back the database.

In my case it processes limit has been exceeded,  so i increase both nodes and restarted the RAC DB.

Check lsnrctl status,

It may show status is blocked.

In my case;

On both nodes ---
SQL> alter system set sessions=800 scope=spfile;

Sistema modificado.

SQL> alter system set processes=1000 scope=spfile;


shutdown immediate
startup ------------  using svctl

processes integer 1000
sessions integer 1500
Because sessions are derived from processes.. Keep in mind...