[dba-VB] Is it possible to develop active ASP.NET Web Services?

Hi Shamil

No I don't think you are missing anything! Perhaps my mind is just missing to see the idea of this? What could such a Cron ASP.NET do to call a web service that you can't do with a tiny console app with a timer?

Is this just for fun or the thinking, or are you looking for a clever way to meet a special challenge?

/gustav

>>> shamil at smsconsulting.spb.ru 09-12-2008 12:55 >>>
Hi Gustav,

But my variation of the "hack" is to have Cron ASP.NET/ASP.NET web service
application, which only duty will be to *ping/wake-up* another ASP.NET web
service to perform recurrent/scheduled tasks: for this architecture/scenario
I do not see currently any problems except that recurrent/schedule tasks
shouldn't be very lengthy - and I do not plan to have them running longer
than several seconds/half-minute/minute - that should be OK with
ASP.NET/ASP.NET web service apps as they are multi-threaded and my
recurrent/scheduled threads will be written assuming they are running in
such environment...

Am I missing something?

Thank you.

--
Shamil

-----Original Message-----
From: dba-vb-bounces at databaseadvisors.com 
[mailto:dba-vb-bounces at databaseadvisors.com] On Behalf Of Gustav Brock
Sent: Tuesday, December 09, 2008 1:13 PM
To: dba-vb at databaseadvisors.com 
Subject: Re: [dba-VB] Is it possible to develop active ASP.NET Web Services?

Hi Shamil

Well, I would run some kind of service, native of Windows or otherwise
external in relation to the site. 
Like many other commenters calling the idea a "hack", I can't see anything
but potential troubles by letting the site itself simulate a Cron job.

/gustav


>>> shamil at smsconsulting.spb.ru 08-12-2008 22:55 >>>
Thank you for your responses Gustav, Drew and William.

Here is what I have just found:

Easy Background Tasks in ASP.NET
http://blog.stackoverflow.com/2008/07/easy-background-tasks-in-aspnet/ 

IOW, the subject task was questioned several months before on StackOverflow,
and a follow-up discussion (on the same referred above page) highlighted all
pluses and minuses of proposed simple solution: I'd try to make it like that
now:

- use proposed above simple solution on "cron" ASP.Net web site/service,
which will query URL on another main ASP.NET web site/service to perform
recurrent tasks...

It should work, shouldn't it?

Thank you.

--
Shamil

-----Original Message-----
From: dba-vb-bounces at databaseadvisors.com 
[mailto:dba-vb-bounces at databaseadvisors.com] On Behalf Of William Hindman
Sent: Monday, December 08, 2008 9:38 PM
To: Discussion concerning Visual Basic and related programming issues.
Subject: Re: [dba-VB] Is it possible to develop active ASP.NET Web Services?

...I don't think you can do this as a pure web service ...but you can invoke
a "with events" protocol from an outside timer/event based call to invoke 
asynchronous Web Service method calls to implement callback events from a 
Web Service to its clients ...hope that makes sense.

William

--------------------------------------------------
From: "Shamil Salakhetdinov" <shamil at smsconsulting.spb.ru>
Sent: Saturday, December 06, 2008 1:22 PM
To: "'Access-D - VB'" <dba-vb at databaseadvisors.com>
Subject: [dba-VB] Is it possible to develop active ASP.NET Web Services?

> Hi All,
>
> ASP.NET Web Services are known to be passive IOW they are activated when
> called from outside, they do some work, and quit until another web request
> comes...
>
> ...I wonder is it possible to develop active web service, which will be
> activating itself once in a while (e.g. by using a kind of schedule
> controlled by timer + some programmatic logic)...
>
> ...that active service could be something like endlessly
> running/sleeping/running... between resets web service method IOW a web
> service method with timeout set to infinitum...
>
> ...because ASP.NET web services application is by definition multi-threaded
> having one thread like the questioned/requested above shouldn't be an issue
> for the other IMO...
>
> ...this thread could be started by outside call or even (I guess) by web
> service itself calling its own method with infinitum timeout on start-up
> *via loopback web service call not directly* or something like that...
>
> ...that questioned/requested solution should be pure ASP.NET web service one
> as it's planned to be used on ASP.Net hosting without access to the host
> operating system to run scheduled Windows Service etc...
>
> ...it could happen that questioned/requested Web Service solution is
> built-in ASP.NET feature: I must say I didn't investigate the docs/I didn't
> try to make a POC solution - I expect somebody here might have done
> something like that already - all I need is an answer: yes, it can be done,
> RTFM => {{URL}}} ...
>
> Thank you.
>
> --
> Shamil
>
> P.S. Sorry, I didn't do in advance investigation - I just didn't want to get
> negative answer by myself - and if positive answer exists I'd be glad to
> share it with you, and you'll be ready for such a "tricky"/unusual (?)
> solution using Web Services in advance...