Database Software

Hi all ,
first I hope I've reached the right forum .

we've developed a .net <--> oracle application , which use oracle web services a lot , and it is great since it reduce our development time (no need to setup middle tier application server for webservice)

However , when trying to scale/stress the solution we've encountered serveral issues , which I would like to know if others has them as well:

1. it seems that the servlet is opening a db connection for every call , this seems a little expensive (I've not tested yet if it a logical connection using shared server of dedicate one -- anyone know ?? ) .
it there a way to tell the servlet to work with connection pool ? or keep the connections open ?

2. if i want to profile/debug/monitor the servlet ? where are the logfiles ?
it seems that the listener log is written for every call (which make sence ) but the it grows big

3. I want to know if anyone is using it on production with large scale (about 100 request per min ) ? or should i think on using web-service middle tier .?

thanks amihay .

we are using 11.2.0.1 on windows 2008 64 bit .