Re: connection pooling dilemma

Lew <>
Thu, 07 Feb 2008 10:36:12 -0500
josh wrote:

Hi, I wrote an application that interact with a database and first
every page like


had the following code:


conn =

so every time I reloaded the driver and so on...

You don't actually reload the driver, nor do you need to call the forName()
for the driver more than once in an application.

Subsequent calls to load a class that's already loaded through the same class
loader do not reload the class.

so I learned some concepts to configure Tomcat to use connection
pooling to improve my db application
and now every page has the following code:

Context initContext = new InitialContext();
Context envContext = (Context)initContext.lookup("java:/comp/env");
DataSource ds = (DataSource)envContext.lookup("jdbc/articoli");
conn = ds.getConnection();

but the mystery for me is that the first time I load the page I have a
net speed measurement of 200 to 400 ms
and then a speed of 10 to 20 ms. But the same I have with no
connection pooling! How is possible?

Do you mean the first time after the application has started in Tomcat? If
so, then most likely you are seeing the overhead to translate the JSP into
Java and compile it into bytecode. You might see this go away if you
pre-compile the JSPs before executing the app.

What is the mystery for me is why you have any Java code (a.k.a. "scriptlet")
in your JSP at all.


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