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Posted to httpclient-users@hc.apache.org by Javier Ramos <jr...@gmail.com> on 2010/12/15 17:44:09 UTC
Re: HttpCore/HttpClient services integration in a J2EE Servlet container
Thanks, Oleg
I understand that reusing an HttpClient instance is a recommended practice,
¿right?
If we push this reuse strategy to the limit then it should be best to have
just one HttpClient with a ThreadSafeClientConnManager in a servlet only
J2EE application (no EJB's).
I am thinking of wrapping this client in a singleton with
1.- A method to configure the conection manager, to be called at context
initialisation (max connections per host, max total connections, etc).
2.- A getter for the HttpClient instance, to be used everywhere in the
application where an HttpClient is required
3.- A method to cleanup everything, to be called on context destroy (would
call shutdown on the connection manager).
Does this setup make sense ?
If it does, having just one instance of HttpClient would provide the
opportunity to monitor it from a servlet. Being able to check the number of
connections established with each host would be a very nice feature, for
example. Or modifying the max connections per host at runtime. However, in
the javadocs I do not find any methods that can allow this information to be
obtained. Is it by design or am I missing something ?
Thanks a lot,
Javier
2010/11/15 Oleg Kalnichevski <ol...@apache.org>
> On Mon, 2010-11-15 at 13:21 +0100, Javier Ramos wrote:
> > Thanks for your feedback, Oleg
> >
> > We are doing with just a servlet container (Tomcat)
>
> My apologies, Javier. I mis-interpreted the subject of your message and
> assumed you were using a full-blown J2EE application server.
>
>
> > I guess that to follow your recommendation with minimal changes to our
> > productive environment we would have to try OpenEJB.
> > Using ThreadSafeClientConnManager inside a servlet container is also
> > discouraged, right ?
> >
>
> There is absolutely no need to drag in OpenEJB with all its dependencies
> just to maintain a pool of HTTP connections. I do not think the Servlet
> specification imposes any restrictions on thread synchronization in the
> web tier components.
>
> > Is anybody using such configurations, or is willing to drop a comment ? (
> > Tomcat + OpenEJB + HttpClient, or Tomcat + ThreadSafeClientConnManager )
> >
>
> I have used HttpClient 3 and HttpClient 4 with a pooling connection
> manager inside various servlet containers such as Tomcat and WebLogic
> without any issues.
>
> Oleg
>
>
>
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Re: HttpCore/HttpClient services integration in a J2EE Servlet container
Posted by Javier Ramos <jr...@gmail.com>.
Hi Oleg,
Yes, it is nice to be able to monitor the number of connections in use.
Would be even better to have it per host.
Thanks again,
Javier
2010/12/15 Oleg Kalnichevski <ol...@apache.org>
> On Wed, 2010-12-15 at 17:44 +0100, Javier Ramos wrote:
> > Thanks, Oleg
> >
> > I understand that reusing an HttpClient instance is a recommended
> practice,
> > ¿right?
> >
> > If we push this reuse strategy to the limit then it should be best to
> have
> > just one HttpClient with a ThreadSafeClientConnManager in a servlet only
> > J2EE application (no EJB's).
> >
> > I am thinking of wrapping this client in a singleton with
> >
> > 1.- A method to configure the conection manager, to be called at context
> > initialisation (max connections per host, max total connections, etc).
> > 2.- A getter for the HttpClient instance, to be used everywhere in the
> > application where an HttpClient is required
> > 3.- A method to cleanup everything, to be called on context destroy
> (would
> > call shutdown on the connection manager).
> >
> > Does this setup make sense ?
> >
>
> Makes sense to me.
>
> > If it does, having just one instance of HttpClient would provide the
> > opportunity to monitor it from a servlet. Being able to check the number
> of
> > connections established with each host would be a very nice feature, for
> > example. Or modifying the max connections per host at runtime. However,
> in
> > the javadocs I do not find any methods that can allow this information to
> be
> > obtained. Is it by design or am I missing something ?
> >
>
> What about ThreadSafeClientConnManager#getConnectionsInPool?
>
>
> http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/impl/conn/tsccm/ThreadSafeClientConnManager.html#getConnectionsInPool%28%29
>
> http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/impl/conn/tsccm/ThreadSafeClientConnManager.html#getConnectionsInPool%28%29
>
> Oleg
>
>
>
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> To unsubscribe, e-mail: httpclient-users-unsubscribe@hc.apache.org
> For additional commands, e-mail: httpclient-users-help@hc.apache.org
>
>
Re: HttpCore/HttpClient services integration in a J2EE Servlet
container
Posted by Oleg Kalnichevski <ol...@apache.org>.
On Wed, 2010-12-15 at 17:44 +0100, Javier Ramos wrote:
> Thanks, Oleg
>
> I understand that reusing an HttpClient instance is a recommended practice,
> ¿right?
>
> If we push this reuse strategy to the limit then it should be best to have
> just one HttpClient with a ThreadSafeClientConnManager in a servlet only
> J2EE application (no EJB's).
>
> I am thinking of wrapping this client in a singleton with
>
> 1.- A method to configure the conection manager, to be called at context
> initialisation (max connections per host, max total connections, etc).
> 2.- A getter for the HttpClient instance, to be used everywhere in the
> application where an HttpClient is required
> 3.- A method to cleanup everything, to be called on context destroy (would
> call shutdown on the connection manager).
>
> Does this setup make sense ?
>
Makes sense to me.
> If it does, having just one instance of HttpClient would provide the
> opportunity to monitor it from a servlet. Being able to check the number of
> connections established with each host would be a very nice feature, for
> example. Or modifying the max connections per host at runtime. However, in
> the javadocs I do not find any methods that can allow this information to be
> obtained. Is it by design or am I missing something ?
>
What about ThreadSafeClientConnManager#getConnectionsInPool?
http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/impl/conn/tsccm/ThreadSafeClientConnManager.html#getConnectionsInPool%28%29
http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/impl/conn/tsccm/ThreadSafeClientConnManager.html#getConnectionsInPool%28%29
Oleg
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