Sorry didnt put subject earlier,
Seems like my question is not clear. I am using connection pooling, though
not an application server, but one provided by oracle driver.
There is a servlet which starts the connection pool when the server is
started i.e. loaded on start up. I initialize the pool, and put it in the
servers context by
ServletContext context = getServletContext();
context.setAttribute("CONNECTION_POOL", cpl);
and then through the servlet i get the connection as.
ServletContext context = getServletContext();
OracleConnectionPool ocpl =
(OracleConnectionPool)context.getAttribute("CONNECTION_POOL");
OracleConnection tmpDbCon = (OracleConnection)ocpl.getConnection();
So now i am saying which method is much better, related to design, number of
clicks on the site.
Putting the connection in the init() method and assigning it the connection
permanently until the server is shutdown. Or getting a connection everytime
a user requests the servlet doPost() and then release it.
Regards,
Vikramjit Singh,
Systems Engineer,
GTL Ltd.
Ph. 7612929-1031
-----Original Message-----
From: It, Cockpit (CAP, Contractor) [mailto:[EMAIL PROTECTED]]
Sent: Monday, June 24, 2002 11:05 PM
To: [EMAIL PROTECTED]
Subject:
Hi Vikramjit,
IMHO, both the practices are not much laudable.
Yes its overhead to the resources to open and close the physical connection
to the database for each request that arrives to your application.
So, this is not better practice to use it.
What your colleague is doing is also wrong. It might look right in one point
that He/She is allotting a single connection to a servlet which will be used
for all the request that particular servlet receives. But just think of a
scenarios
1. where in more than one requests are coming to that servlet.......your
servlet will keep the request in a web server's queue.
Though your servlet is capable of handling more than one request at a time,
it won't. Because it does not have a database connection in hand, which
might be used by some other request arrived just before to this request.
2. Just think your application is having around 200 servlets which have to
interact with the database. so when all your servlets have been accessed by
the users at least for one time. Then your database will have 200
connections open till your webserver/app server restarts which will destroy
your servlets as well as connections. So Ideally you are locking the
connections. Just think that one of your servlet is being accessed once in a
week, that servlet will have a open connection till it's next request
reaches.
So the ideal way of handling connections would be ConnectionPooling. If you
use App Server you can make use of it, because all the app server, that I
know of, are providing facility for connection Pooling.
If you are working with Web server just try to implement your own connection
pooling concept, or just find one from the web, which are surely available
on the net.
But inefficient connection pool handling will also be a problem, so just
take care of it.
Basically in connection pool that has been implemented by your app server
vendor would have a wrapper class to your connection object. so when you say
connection.close() it basically tells the app server that you are done with
using your connection, so it will collect your connection back to the pool.
So using as minimum as 10 connections u can serve more than 100 users. Just
search for Connection pool on google. you will get more about it.
All the best.
Yogaraj
-----Original Message-----
From: Vikramjit Singh [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 25, 2002 11:00 AM
To: [EMAIL PROTECTED]
Subject:
Hi all,
I have a doubt in which method is the proper way of getting connections. I
am putting the connections in the server context, and getting the
connections from the context by
ServletContext context = getServletContext();
OracleConnectionPool ocpl =
(OracleConnectionPool)context.getAttribute("CONNECTION_POOL");
OracleConnection tmpDbCon = (OracleConnection)ocpl.getConnection();
First Method:
I usually get the connection by the above method by putting it in the doPost
method of the servlet.
like public void doPost(HttpServletRequest req, HttpServletResponse res){
ServletContext context = getServletContext();
OracleConnectionPool ocpl =
(OracleConnectionPool)context.getAttribute("CONNECTION_POOL");
OracleConnection tmpDbCon = (OracleConnection)ocpl.getConnection();
}
My colleague says that this method has its overheads since each and
everytime you fetch and release a connection. Which should be avoided.
So she tried the second method
Second Method:
Instead of fetching the connection from doPost method, she put it in the
init() method of the servlet like this
public void init()
{
ServletContext context = getServletContext();
OracleConnectionPool ocpl =
(OracleConnectionPool)context.getAttribute("CONNECTION_POOL");
OracleConnection tmpDbCon = (OracleConnection)ocpl.getConnection();
}
Now the servlet will always have a connection. This connection shall be
released only when the destroy() method of the servlet is called. She says
this is better, since you dont everytime have to get and release the
connection. You have assigned one connection to it. If many users access
this servlet, then the service method shall handle it.
Could some java gurus throw some light on this.
Regards,
Vikramjit Singh,
Systems Engineer,
GTL Ltd.
Ph. 7612929-1031
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