I completely agree.

+1 for branch if Aleksey wants to experiment


On 10/27/06, Xiao-Feng Li <[EMAIL PROTECTED]> wrote:

All, I think the problem now is mainly about the class unloading
design not about whether class unloading happens in server
environment.

Class unloading is definitely a feature required in future; but with
the significance of the required modifications in JVM by this class
unloading design 2 (using Java object for Vtable), it is probably
safer to move this work into a branch at the moment until all other
components are ready for it, and after we have thorough evaluation on
it since there are still issues to be resolved or discussed.

Or we can keep it in JIRA and keep the discussion and evaluation going
on before we decide to support the special design (Java Vtable) in
other components.

How about it?

Thanks,
xiaofeng

On 10/27/06, Geir Magnusson Jr. <[EMAIL PROTECTED]> wrote:
>
>
> Rana Dasgupta wrote:
> > My knowledge in this area is limited. But my understanding was that
web
> > servers and other similar hosts recycled processes periodically as
> > standard procedure, thereby tearing down all associated resources.
>
> Yes, but that has nothing to do with what would be happening in the app
> server the web server talked to, if one had an architecture where a web
> server "fronted" for the app server.
>
> > So
> > classes loaded, but not used for a while went away anyway;
>
> Nope - they aren't loaded in the context of the webserver (when using
> httpd).
>
> > this level of
> > resource management was not really urgent. I know that IIS does this,
I
> > am not sure about httpd. I am not sure about other host environments.
>
> But a process fork model (or thread model) of a webserver has nothing to
> do with what's going on in the VM.
>
> I'm talking about servlet engines and app servers like Tomcat and
> Geronimo which have nothing to do with httpd.  Architecturally, they are
> separated from the web server (unless you don't use an external
> webserver, and just use the httpd connector in tomcat) and are separate,
> independent processes.
>
>      httpd  <------>  Tomcat
>
> The java-based app servers are long running processes, running for weeks
> or months.  We need to do clean class unloading.
>
> geir
>
>
> >
> >
> > On 10/27/06, *Geir Magnusson Jr.* <[EMAIL PROTECTED]
> > <mailto:[EMAIL PROTECTED]>> wrote:
> >
> >
> >
> >     Rana Dasgupta wrote:
> >      > Aleksey,
> >      >   I had a couple of questions.
> >      >   You state that DRLVM does not implement the class unloading
> >     optimization,
> >      > and this may create memory pressure on some applications that
> >     load many
> >      > classes. Do we have a real case / example where an application
is
> >     stuck for
> >      > insufficient memory because it uses a lot of classes initially
> >     and then
> >      > stops using them, but these are not unloaded? One can imagine a
> >     web browser
> >      > doing something like this. Is a web browser a typical use case
> >     for the
> >      > Harmony JVM?
> >      >
> >
> >     If I understand what you're asking correctly, you'll find this
pattern
> >     in servlet engines or J2EE servers, where deployed apps can be
dumped
> >     and reloaded repeatedly either during development or during
production
> >     deployment, w/o taking the server down.
> >
> >     geir
> >
> >
>

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