[undertow-dev] Resizing undertow thread pool size dynamically

[Stuart Douglas]

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
> >>
> >
> >
>