Handling "XForms error: Unable to retrieve XForms engine state from session cache."

>
>  You could have a javascript timer that fires dummy XForms submission events
> to keep the session alive?
>
>  If your session timeout is long (eg 20 min) it would have to fire very
> infrequently.
>
>  Adrian
>
>
>  Larry T. Chen wrote:
>  Fellow Orbeon Forms Users,
>
>  Recently there was a question regarding this issue, but there seemed to be
> no working solution yet.
>  When the session times out, the familiar error "XForms error: Unable to
> retrieve XForms engine state from session cache." shows up in red.
>  The only way to fix this that I know so far is to do a Shift-Reload on the
> page.
>
>  Obviously telling users to do a Shift-Reload will not be satisfactory in a
> production environment.  How is everyone
>  handling this right now?  Are there any working solutions that are useable
> and deployable in production?
>
>  Before I was using client state handling to avoid this problem .. but I've
> discovered that it's much slower ...
>  so for performance reasons we must use session state handling.
>
>  Larry T. Chen
>  Intelenet Communications, Inc.
>
>
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>
>

> Larry,
>
> Also using a JavaScript timer, another approach is to take the user to
> a "your session has expired" page. On that page you can explain what
> happened, and provide a few links on what to do next. Optionally you
> can log the user out, for additional security.
>
> I think I prefer the method presented by Adrian, as it is more
> transparent to the user. One drawback though is that if you have a lot
> of people just leaving their browser open but not using the
> application, you will end up keeping a lot of sessions open on the
> server.
>
> Alex
>
> On 4/25/07, Adrian Baker <[hidden email]> wrote:
>>
>>  You could have a javascript timer that fires dummy XForms submission
>> events
>> to keep the session alive?
>>
>>  If your session timeout is long (eg 20 min) it would have to fire very
>> infrequently.
>>
>>  Adrian
>>
>>
>>  Larry T. Chen wrote:
>>  Fellow Orbeon Forms Users,
>>
>>  Recently there was a question regarding this issue, but there seemed
>> to be
>> no working solution yet.
>>  When the session times out, the familiar error "XForms error: Unable to
>> retrieve XForms engine state from session cache." shows up in red.
>>  The only way to fix this that I know so far is to do a Shift-Reload
>> on the
>> page.
>>
>>  Obviously telling users to do a Shift-Reload will not be satisfactory
>> in a
>> production environment.  How is everyone
>>  handling this right now?  Are there any working solutions that are
>> useable
>> and deployable in production?
>>
>>  Before I was using client state handling to avoid this problem .. but
>> I've
>> discovered that it's much slower ...
>>  so for performance reasons we must use session state handling.
>>
>>  Larry T. Chen
>>  Intelenet Communications, Inc.
>>
>>
>> --
>> You receive this message as a subscriber of the [hidden email]
>> mailing list.
>> To unsubscribe: mailto:[hidden email]
>> For general help: mailto:[hidden email]?subject=help
>> ObjectWeb mailing lists service home page: http://www.objectweb.org/wws
>>
>>
>
>

> Recently we have done some load and performance testing of our application
> which uses OF  mostly for the purpose of transforming XForms to HTML (plus
> couple more XSLT transforms which gives us few of our own components).
> The results have been somewhat disappointing.
> As most of the time, according to JProbe, is spend in the XSLT engine we
> have tried to optimize all XSLT transformations which gave us only about 10%
> speed increase. We are thinking the biggest increase would come from
> optimizing XForms to HTML transformation.
> So my question is would it make sense to try compiling this XSLT into a
> translet?
> If so, this is only supported for XSLT 1.0, would it be even possible to
> port form XSLT 2.0 back to XSLT 1.0?
>
> Also, is there some optimization roadmap for OF, if so what is it?
>
> -peter
>
>
>
>
> --
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> To unsubscribe: mailto:[hidden email]
> For general help: mailto:[hidden email]?subject=help
> ObjectWeb mailing lists service home page: http://www.objectweb.org/wws
>
>

> Hi Peter,
>
> Yes, performance is one of our top priorities You are saying that most
> of the time is spent in XSLT code when generating the page. What XSLT
> is that?
>
> Orbeon Forms ships out of the box with a processor which uses the
> Xalan XSLTC implementation. This will compile your stylesheets, and in
> theory give you better performance. However, the drawbacks with XSLTC
> is that it does not support XSLT 2.0, and also have a number of other
> bugs/limitations. My experience with XSLTC dates from a couple of
> years ago so things might have changed since then.
>
> Alex
>
> On 4/27/07, Peter Kolarov <[hidden email]> wrote:
>> Recently we have done some load and performance testing of our
>> application
>> which uses OF  mostly for the purpose of transforming XForms to HTML
>> (plus
>> couple more XSLT transforms which gives us few of our own components).
>> The results have been somewhat disappointing.
>> As most of the time, according to JProbe, is spend in the XSLT engine we
>> have tried to optimize all XSLT transformations which gave us only
>> about 10%
>> speed increase. We are thinking the biggest increase would come from
>> optimizing XForms to HTML transformation.
>> So my question is would it make sense to try compiling this XSLT into a
>> translet?
>> If so, this is only supported for XSLT 1.0, would it be even possible to
>> port form XSLT 2.0 back to XSLT 1.0?
>>
>> Also, is there some optimization roadmap for OF, if so what is it?
>>
>> -peter

> Hi,
>
> while i hope to get help on another thread i was searching and found
> this one.
> Is there a chance to catch this "XForms error - Event" and redirect to a
> start page i.e.?
> This point was mentioned some mails ago in this thread, but i think
> there was no working solution or answer yet how this can be
> established!? A redirect to a start-page showing the user the
> information, that his session-time hast gone out would be great!
>
> Best wishes,
> Marcus
>

> Marcus,
>
> We have an RFE for this:
>
> http://forge.objectweb.org/tracker/index.php?func=detail&aid=306868&group_id=168&atid=350207
>
> But no implementation yet!
>
> We are also planning to improve the way the session cache works so that
> it causes this message to appear less often. I just entered this bug,
> which we have discussed recently:
>
> http://forge.objectweb.org/tracker/index.php?func=detail&aid=307056&group_id=168&atid=350207
>
> -Erik
>
> Marcus wrote:
>> Hi,
>>
>> while i hope to get help on another thread i was searching and found
>> this one.
>> Is there a chance to catch this "XForms error - Event" and redirect to a
>> start page i.e.?
>> This point was mentioned some mails ago in this thread, but i think
>> there was no working solution or answer yet how this can be
>> established!? A redirect to a start-page showing the user the
>> information, that his session-time hast gone out would be great!
>>
>> Best wishes,
>> Marcus
>>
>
>
> --
> Orbeon Forms - Web Forms for the Enterprise Done the Right Way
> http://www.orbeon.com/
>
>