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@gmail.com> wrote:
I am using Wildfly.

Thanks,

Mohammed.

On Wed, Aug 12, 2015 at 10:55 AM, Stuart Douglas <sdouglas@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@gmail.com>
> To: "Jason Greene" <jason.greene@redhat.com>
> Cc: undertow-dev@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@redhat.com >
> wrote:
>
>
>
> > On Aug 11, 2015, at 4:42 AM, Mohammed ElGhaouat < melghaouat@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
>
>
>
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