[undertow-dev] Resizing undertow thread pool size dynamically

[Stuart Douglas]

----- Original Message -----
> From: "Mohammed ElGhaouat" <melghaouat at gmail.com>
> To: "Stuart Douglas" <sdouglas at redhat.com>
> Cc: "Jason Greene" <jason.greene at redhat.com>, undertow-dev at lists.jboss.org
> Sent: Tuesday, 20 October, 2015 2:22:58 AM
> Subject: Re: [undertow-dev] Resizing undertow thread pool size dynamically
> 
> Is this valid for Wildfly? (I am using 8.2.1)

Yes, this is valid for all Servlet deployments, in both Wildfly and embedded Undertow. 

Wildfly will still create its worker thread pool, but it should not get used for this deployment. 

Stuart

> 
> From the previous replies, I understood that the ServletExtension could be
> used for embedded Undertow not for Wildfly. Anyway, I gave it a try, but
> still having Wildfly using task-max-threads and io-threads parameters from
> (subsystem=io/worker=default/).
> 
> To test this solution, I created a simple wepapp with one simple Servlet
> and my ServletExtension.handleDeployment is executed by the Wildfly.
> 
> 
> Thanks
> 
> On Sat, Oct 17, 2015 at 3:01 PM, Stuart Douglas <sdouglas at redhat.com> wrote:
> 
> > Like I said, you can use any thread pool you want if you modify it using a
> > ServletExtension.
> >
> > Code looks like:
> >
> >
> > public class MyExtension implements ServletExtension {
> >
> >     @Override
> >     public void handleDeployment(DeploymentInfo deploymentInfo,
> > ServletContext servletContext) {
> >        Executor myThreadPool = {my thread pool};
> >        deploymentInfo.setExecutor(myThreadPool);
> >     }
> > }
> >
> > Then add a META-INF/services entry for the extension.
> >
> > Stuart
> >
> > ----- Original Message -----
> > > From: "Mohammed ElGhaouat" <melghaouat at gmail.com>
> > > To: "Stuart Douglas" <sdouglas at redhat.com>
> > > Cc: "Jason Greene" <jason.greene at redhat.com>,
> > undertow-dev at lists.jboss.org
> > > Sent: Wednesday, 14 October, 2015 12:22:20 PM
> > > Subject: Re: [undertow-dev] Resizing undertow thread pool size
> > dynamically
> > >
> > > Hello,
> > >
> > > I would like to share with you some more details about our situation. We
> > > are using some big machines that are shared by many software(many Wildfly
> > > instances, Databases, ERPs ..) If i don't set pools sizes i end up with
> > big
> > > pools as the default size is dependent on the number of CPU cores and out
> > >  system administrator is complaining about the OS spending time checking
> > if
> > > the threads have something to do and this impact the other softwares
> > > installed on the same machine. If I set a small pool size which could
> > > sufficient in the 90% of time, i am afraid that  Wildfly couldn't handle
> > > the 10% of time when the applications are used by a large number of user.
> > >
> > > Is there any workaround or are you planning to let the user to set a
> > > specific ThreadPoolExecutor ? so we can evict idle threads
> > >
> > >
> > > Thanks,
> > >
> > > Mohammed.
> > >
> > >
> > > On Wed, Aug 12, 2015 at 11:03 AM, Mohammed ElGhaouat <
> > melghaouat at gmail.com>
> > > wrote:
> > >
> > > > I am using Wildfly.
> > > >
> > > > Thanks,
> > > >
> > > > Mohammed.
> > > >
> > > > On Wed, Aug 12, 2015 at 10:55 AM, Stuart Douglas <sdouglas at redhat.com>
> > > > wrote:
> > > >
> > > >> Are you using Wildfly or embedded Undertow?
> > > >>
> > > >> If it is the later you can just use
> > > >> io.undertow.servlet.api.DeploymentInfo#setExecutor to use whatever
> > > >> executor
> > > >> implementation you want.
> > > >>
> > > >> The reason why most executors don't reduce the number is because
> > there is
> > > >> generally very little point, a parked thread is generally very cheap,
> > > >> while
> > > >> creating new threads is relatively expensive.
> > > >>
> > > >> Stuart
> > > >>
> > > >> ----- Original Message -----
> > > >> > From: "Mohammed ElGhaouat" <melghaouat at gmail.com>
> > > >> > To: "Jason Greene" <jason.greene at redhat.com>
> > > >> > Cc: undertow-dev at lists.jboss.org
> > > >> > Sent: Wednesday, 12 August, 2015 6:19:11 PM
> > > >> > Subject: Re: [undertow-dev] Resizing undertow thread pool size
> > > >> dynamically
> > > >> >
> > > >> > We are using the servlet API and I am referring to worker pool.
> > Simply
> > > >> we
> > > >> > don't want keeping bunch of idle threads in the JVM consuming some
> > > >> resources
> > > >> > without doing any thing useful.
> > > >> >
> > > >> > So with the bounded queue executor, when the value of the
> > > >> task-max-threads
> > > >> > parameter is reached, the number of threads in the worker pool
> > couldn't
> > > >> be
> > > >> > decreased ?
> > > >> >
> > > >> > Thank you.
> > > >> >
> > > >> >
> > > >> > Mohammed.
> > > >> >
> > > >> > On Tue, Aug 11, 2015 at 9:50 PM, Jason Greene <
> > jason.greene at redhat.com
> > > >> >
> > > >> > wrote:
> > > >> >
> > > >> >
> > > >> >
> > > >> > > On Aug 11, 2015, at 4:42 AM, Mohammed ElGhaouat <
> > > >> melghaouat at gmail.com >
> > > >> > > wrote:
> > > >> > >
> > > >> > >
> > > >> > > Hi,
> > > >> > >
> > > >> > > I would like to know if there is a way to make undertow reducing
> > the
> > > >> size
> > > >> > > of the thread pool when the server is less loaded. Is there any
> > > >> > > parameter(or other way) that make an idle thread die after some
> > > >> inactivity
> > > >> > > time ?
> > > >> >
> > > >> >
> > > >> > Are you referring to the worker pool or the I/O pool? The I/O pool
> > is
> > > >> special
> > > >> > and is fixed. The worker pool currently uses a JDK
> > ThreadPoolExecutor
> > > >> with
> > > >> > an unbounded queue which is a behavior pattern typically desired
> > for web
> > > >> > servers. That’s not pluggable at the moment, but it could be
> > possible.
> > > >> >
> > > >> > If you are using the HttpHandler APIs, there is a method on
> > > >> > HttpServerDispatch that allows you to use your own custom executor
> > for
> > > >> > blocking tasks (which would allow you to tune the default worker
> > task
> > > >> pool
> > > >> > very small). If you are using servlet APIs though that uses the
> > standard
> > > >> > pools we provide.
> > > >> >
> > > >> > Is there a particular reason you want to kill idle threads? Threads
> > are
> > > >> cheap
> > > >> > unless you are storing massive amounts of thread local data.
> > > >> >
> > > >> > --
> > > >> > Jason T. Greene
> > > >> > WildFly Lead / JBoss EAP Platform Architect
> > > >> > JBoss, a division of Red Hat
> > > >> >
> > > >> >
> > > >> >
> > > >> > _______________________________________________
> > > >> > undertow-dev mailing list
> > > >> > undertow-dev at lists.jboss.org
> > > >> > https://lists.jboss.org/mailman/listinfo/undertow-dev
> > > >>
> > > >
> > > >
> > >
> >
>