[jboss-as7-dev] Limiting Server Thread Usage

[David Bosschaert]

On 15/09/2011 01:10, Remy Maucherat wrote:
> On Wed, 2011-09-14 at 12:03 -0700, Scott Stark wrote:
>> The question of whether this is the right limit is one I have raised,
>> especially since the limit is being imposed via a pam_limits module
>> which actually limits the number of processes a user is allowed. A java
>> thread is mapping to a process in this model, which further blurs the
>> effectiveness/validity.
>>
>> However, this is an issue that does commonly come up with system admins
>> as a way of gauging max requests and therefore some measure of the max
>> resource requirements.
>>
>> Perhaps a global limit is really not an effective approach.
>>
>> Similar to how we have a global view of ports in use, perhaps just
>> having a global view of the thread pools in the domain model stats would
>> be enough. If I can see of the server thread pools with the min/max
>> settings, and there is a base thread pool dsl for min/max settings in
>> every subsystem utilizing a thread pool, one can at least understand the
>> thread usage, and make some choices about how to limit it.
> I think it is a good idea if all subsystems can be configured to use a
> single thread pool for all their application threads. However, I think
> this limit should mean user threads, not including the threads the
> server and JVM already use.
>
> If you say, for example, that there are 50 threads max, it should mean
> that the user can have up to 50 threads running his servlets, not that
> he can have 25 threads used by the server + JVM (that they will never
> let go), and actually only up to 25 that can do something for him.
>
I wonder how that would work for the OSGi subsystem since in OSGi user 
code is allowed to create new java.lang.Thread objects...

Cheers,

David