Hello,

> One thing you have to do with pooling is be sure to close all statements and
> result sets on a connection.

That's what i do...
try {
Connection c = ds.getConnection();
String sql = "SELECT USER_ID FROM US_USER WHERE USERNAME = ?;";
PreparedStatement ps = c.prepareStatement(sql);
ps.setString(1, "smue");
ResultSet rs = ps.executeQuery();
if (rs.next()) {
write("next() succeeded...");
}
rs.close();
ps.close();
c.close();
}
catch (SQLException e) {
write(e.getMessage());
}

> In a non-pooling environment closing a
> connection closes all result sets and statements. If you close a connection
> in a pooling environment the connection is not actually closed but returned
> to the pool, so open statements and results sets survive.
>
> This will eat up all the available connections. To keep it from tying up
> your entire system you can set the number of open connections to a non-zero
> number. That way only Firebird will run out of resources rather than your
> system.
>
> The real fix is to go through your code and find all instances of closing a
> connection and add the code to explicitly close the statements and result
> sets used by the connection before closing the connection itself.
>

I don't agree with you.
After executing the above code i do not have any open statements or
resultsets.
The connection returns to the pool and after idleTimeout in
ConnectionPool is gone, the pool tries to return the connection to
firebird (this is where the problem is, the connection is not properly
returned to the firebird engine).
The connectionpool immediately tries to fetch a new connection (because
minSize is set to >0 and returns it again after idleTimeout is gone.
Even if i do not use any connections they are created (because minSize)
and destroyed again (because idleTimeout).
You can try to create a FBWrappingDataSource with idleTimeout set to
1000 ms. After opening and closing a connection (you have to do this
only once for initialisation), your firebird-server will after 10
seconds have 10 open connections!!
I don't think that's correct.

Greetings

Stefan