Open/total jdbc connections

Question

With Oracle9iR2 AS installed, I notice that there are always open JDBC connections. I explicitly close them from all my JSP files (and the statement and the resultset objects as well). Actually, the total JDBC connections are always 2 times the open JDBC connections.
The DataSource class I use is com.evermind.sql.DriverManagerDataSource. Is this a problem? Will this be corrected in any future release?
Thanx

Answer 1

Interesting thread. Have also had problems with the connection pool (903 standalone).
One problem in particular is that if min-connections is used, then those pool-connections are really never closed "physically". This means that a lot of open cursors are never released in the db (even though the "connections" used by the code from the pool are closed). Not so good under heavy load.
Posting a snippet from a connection pool entry we have. Maybe it will help some of you guys.
<data-source
class="com.evermind.sql.DriverManagerDataSource"
name="SomeDS"
location="jdbc/SomeDBCoreDS"
xa-location="jdbc/xa/SomeDBXADS"
ejb-location="SomeDB"
connection-driver="oracle.jdbc.driver.OracleDriver"
username="user"
password="pwd"
url="jdbc:oracle:thin:@127.0.0.1:1521:SOMESID"
inactivity-timeout="300" <-- Will close connections after 300 sec of inactivity
min-connections="0"
max-connections="20" <-- Larger on prod machine of course
stmt-cache-size="100"
/>
I have experimented wildly with these settings and this is the most stable. Sure, it's nice to always have connections ready in the pool. But as I said. Open cursors WILL accumulate in your db if you use the min-connections set to a positive number (check your v$). This is our experience anyway. These settings have stopped us from getting db errors such as maximum open cursors exceeded and too many connections open using 903.
Regards,
Jonas