ORA-12519, TNS:no appropriate service handler found

Caused by: oracle.net.ns.NetException: Listener refused the connection with the following error:
ORA-12519, TNS:no appropriate service handler found  

SQL> set lines 200

SQL> select * from v$resource_limit where resource_name = 'processes';

RESOURCE_NAME                  CURRENT_UTILIZATION MAX_UTILIZATION INITIAL_ALLOCATION                       LIMIT_VALUE                                  CON_ID

------------------------------ ------------------- --------------- ---------------------------------------- ---------------------------------------- ----------

processes                                      988            1000       1000                                     1000                                        0

SQL> select count(1) FROM v$session;

  COUNT(1)

----------

       969

SQL> select status,count(1) FROM v$session group by status;

STATUS     COUNT(1)

-------- ----------

ACTIVE           46

INACTIVE        923

We have seen lots if INACTIVE sessions which we need to kill.  After killing sessions that were INACTIVE for a very long time. We don't see the errors anymore after re-executing the deployment.

SQL> select status,count(1) FROM v$session group by status;

STATUS     COUNT(1)

-------- ----------

ACTIVE           46

INACTIVE        310

SQL> select count(1) FROM v$session;

  COUNT(1)

----------

       356

SQL>