[Yanel-dev] Running background jobs in the background using threads

[Balz Schreier]

Hi Michael,
I have just quickly read your mail and I think it would be a great idea to
look into the Glassfish Application Server, as one framework in there
(called Grizzly) is solving this properly (uses NIO for the threading part
and leverages protocols like Comet / Bayeux Protocol for the front end part,
and)... and as far as I know, Grizzly is reusable as a single component...
sounds ideal to me for Yanel?

http://grizzly.java.net/

The advantage of this would be that it is heavily tested and used already in
large productive applications... on top of that, I have the greatest respect
from "threading in java" :-) I know it got much more convenient with the
advent of java.util.concurrent by JDK 1.5, but none the less: Brian G=F6tz
still writes: "it does not matter how good you are in programming, a
threading application has always bugs":

By the way: His book is great:
http://www.briangoetz.com/pubs.html

I can bring it to the office once, if you're interested.

Cheers
Balz

On Mon, Nov 22, 2010 at 10:16 PM, Michael Wechner <michael.wechner at wyona.com
> wrote:

> Hi
>
> Quite often one has to process something which can take more time than
> which is expected from
> a regular request. Hence it's nice if one can start threads running in the
> background and Yanel
> already sends a response with a note saying "hey, we are working on it ...
> please stay tuned ...".
>
> Yanel does offer such a component which simplifies such threads:
>
>
> src/impl/java/org/wyona/yanel/impl/resources/usecase/thread/ThreadUsecase=
Resource.java
>
> and in order to stay tuned the thread ID is attached to the HTTP session.
> But the problem with this
> approach is that the session might expire before the job is finished, hen=
ce
> I have added a note to
>
> Index:
> src/impl/java/org/wyona/yanel/impl/resources/usecase/thread/ThreadUsecase=
Resource.java
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> ---
> src/impl/java/org/wyona/yanel/impl/resources/usecase/thread/ThreadUsecase=
Resource.java
>    (revision 54828)
> +++
> src/impl/java/org/wyona/yanel/impl/resources/usecase/thread/ThreadUsecase=
Resource.java
>    (working copy)
> @@ -123,6 +123,7 @@
>      * @return thread or null if the thread is not attached to the sessio=
n.
>      */
>     public UsecaseThread getThread() {
> +        // TODO: Is it really a good idea to set/get the thread ID within
> the session, because what if the session expires?!
>         HttpSession session =3D getEnvironment().getRequest().getSession(=
);
>         return UsecaseThread.getThreadFromSession(session, getThreadID());
>     }
>
> I think it probably would be safer to attach it to the user profile which
> has started it (in case it has been started
> by a user).
>
> WDYT?
>
> Cheers
>
> Michael
> --
> Yanel-development mailing list Yanel-development at wyona.com
> http://lists.wyona.org/cgi-bin/mailman/listinfo/yanel-development
>
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