Re: Server detection of client crash

Thanks. I think Joseph said it before and I agree with him. If it's
something of that nature, I would likely try to stay from web stuff.
However, that doesn't mean is not possible or there are no ways to
ensure what you want.

I recently had the chance to speak with a few guys at RedHat about a
project they have been working on based on GWT. I've been meaning to
let people know about it because I was really impressed by a couple of
things I saw. One of them can truly help you and make your requirement
easier or a lot easier to implement.

http://www.jboss.org/errai

A few things:

a) You don't need jboss to use it.
b) Take special attention to CDI (crazy cool and useful).
c) They've done something really interesting where you truly have a
transparent web/server application, blurring completely the lines
between server and UI. Via an annotation you have Server Push. Their
Dependency Injection I thought was also nicer than GIN for the UI.
Although I use GIN and love it!

So what you could do, assuming that you truly want to keep this web
based is to have the server contacting the UI every x amount of
seconds. If no response is received from the UI, then you know that
something is not right. That would be better I think than polling the
server.

Again, this could be done without errai, but take a look at it if you
get a chance.

Best regards,

Alfredo

On Fri, Apr 27, 2012 at 4:44 PM, mmorckos <mikey.morckos@gmail.com> wrote:
> What I meant by "crash" is that the client doesn't "cleanly". For
> instance, the user can simply close the web-page, or the client's
> machine can lose connection to the server. I'm asking if there is a
> way that the server can detect that instantly (some sort of a
> heartbeat ping between the client and the server, unlike a session
> timeout).
>
> On Apr 27, 10:47 am, Alfredo Quiroga-Villamil <laww...@gmail.com>
> wrote:
>> Can you please define or explain what you mean by "whenever a client crashes"?
>>
>> Thank you in advance,
>>
>> Alfredo
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Fri, Apr 27, 2012 at 1:49 AM,mmorckos<mikey.morc...@gmail.com> wrote:
>> > Hello,
>>
>> > I'm intending to develop a web-based frontend UI for a control system
>> > in a research lab. For safety purposes, it's vital that when a client
>> > crashes, the server is notified immediately and dispatches a stop
>> > signal to all connected machinery.
>>
>> > I'm new to gwt and would like to know if there is a way to know
>> > whenever a client crashes on the server side, specifically inside a
>> > "RemoteServiceServlet".
>>
>> >  Regards,
>> > Michael
>>
>> > --
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>> --
>> Alfredo Quiroga-Villamil
>>
>> AOL/Yahoo/Gmail/MSN IM:  lawwton
>
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--
Alfredo Quiroga-Villamil

AOL/Yahoo/Gmail/MSN IM:  lawwton

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