Your application is blocked? Perhaps it is due to deadlock on database objects. So, if you have an Oracke DB Server, you can verify this with these few requests I found on the web :
- List blocked sessions : select sid, serial#, username, command, lockwait, osuser from v$session where lockwait is not null
- Find SQL requests concerned : select sql_text from v$sqltext where (address,hash_value) in (select sql_address,sql_hash_value from v$session where lockwait is not null) order by address, hash_value, piece
- Kill concerned session (you need to have dba priviledges) : alter system kill session 'sid, serial#';