D H wrote:
Oleg and Ortwin,
On Mon, Jun 15, 2009 at 4:07 PM, Oleg Kalnichevski <[email protected]> wrote:
David,
Another big issue is that a new instance of HttpClient is created for each
new request. This is enormously wasteful, as every time there likely to be
an open connection going out of scope, which needs to be GC-ed in order to
free up system resources.
Thank you for all of the advice, I've been talking with my boss quite a bit
and he wants me to document the best practices for HttpClient so that we can
have the developers fix the problems with their code. The application is a
website that uses well over a hundred different URLs. I found a
MultiThreadedExample at
http://svn.apache.org/viewvc/httpcomponents/oac.hc3x/trunk/src/examples/MultiThreadedExample.java?revision=608014but
it looks like you have to declare all of the URLs that it is going to
use?
No, you certainly do not have to.
Could I just declare a static MultiThreadedHttpConnectionManager in a
Servlet, statically set the parameters to initialize it and then use it like
this:
You will be much better off using ServletContextListener to create and
shut down MultiThreadedHttpConnectionManager and ServletContext to store
the reference to that instance.
HttpClient client = new HttpClient(connectionManager);
PostMethod post = new PostMethod(inUrl);
try {
post.setRequestEntity(new StringRequestEntity(inPayload, null,
null));
int statusCode = client.executeMethod(post);
payload = SlowUtilities.readPayload(post);
} finally {
post.releaseConnection();
}
Or do you recommend using the SimpleHttpConnectionManager for situations
like ours?
One should definitely use MultiThreadedHttpConnectionManager in a
servlet container.
You should re-use HttpClient instance for multiple request and shut down
its connection manager when it is no longer used.
I'm not sure when the connection manager would be shut down though, this is
a 24/7 application for a medical center and really only goes down when this
slowdown problem occurs that renders the site unusable.
ServletContextListener is your friend.
Could I just call
closeIdleConnections() every once in a while to do some cleanup?
Yes, you should.
Besides, upgrading to Httpclient 4.0 may be a big jump, but there is no
excuse for not upgrading to HttpClient 3.1
I'm working on getting them to agree to upgrade to HttpClient 3.1. The
application depends on a lot of different libraries so I don't know how
easily they could upgrade to HttpClient 4.0 but I'll look into it.
HttpClient 4.0 is _massively_ better than 3.x version and is better
documented. You should tell your boss to seriously consider upgrading.
Besides, 3.x code line is effectively at the end of life.
It is just a matter of time I _personally_ will stop answering any
questions about HttpClient 3.x
Cheers
Evil Comrade Oleg
I greatly appreciate everyone's help,
David Hamilton
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
