java.sql.SQLException: Listener refused the connection with the following error: ORA-12519, TNS:no appropriate service handler found

Question

I am passing Resultset object to each thread. Each thread is connecting to the database and inserting data. Untill thread 110 it is working fine. After it crosses 111 thread it

Answer 1

I guess the database just don't accept more connections from your host. If I understand your question right you are making maybe 100 threads which each connects to the database in short time. Maybe you don't even close the connection correctly, or the accesses are lasting so long that a huge amount of connections are opened. The database have a limit to which it accepts connections.

You should definitely reduce the number of connections by some clever technique. Maybe reduce the number of concurrent threads and/or use a connection pool.