ASP .NET Application vs. Windows Service

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Untitled

I have an ASP .NET web application that displays information. At the
same time, i have a web service that collects information from various
client applications. This data needs to be processed continuously in
many ways and stored in the database. I need timers to poll the data
and process on it and write to the database. I need to have lots of
data cached as objects in memory as it is being used all the times. I
need to generate weekly reports from data in the database.

My question is this. Can I do this all in ASP .NET or do I need to have
a windows service? Can i keep my web application alive and all the
timers working? Has anyone done this before, actually used an ASP .NET
Application in this way?

Thanks

Mark
 
I have an ASP .NET web application that displays information. At the
same time, i have a web service that collects information from various
client applications. This data needs to be processed continuously in
many ways and stored in the database. I need timers to poll the data
and process on it and write to the database. I need to have lots of
data cached as objects in memory as it is being used all the times. I
need to generate weekly reports from data in the database.

My question is this. Can I do this all in ASP .NET or do I need to have
a windows service? Can i keep my web application alive and all the
timers working? Has anyone done this before, actually used an ASP .NET
Application in this way?

Thanks

Mark
Click to expand...

You can do it either way.

But, if as you describe, your data source supports webservice protocols (ie,
SOAP), and there is to be no user interaction at the receiver, then you'd
probably want to implement as a webservice.

-- ipgrunt
 
For important timed background tasks as you describe, a Windows Service is
the best tool for the job. You might be able to coax ASP.NET into doing it,
but it would be a bit like trying to fit a square peg into a round hole.
 
Steve C. Orr said:
For important timed background tasks as you describe, a Windows Service is
the best tool for the job. You might be able to coax ASP.NET into doing
it, but it would be a bit like trying to fit a square peg into a round
hole.
Click to expand...

I wish there was an easy way to do this in IIS, since it forces you to
either run your code in two processes or use remoting.

If you web site is doesn't need the security and other services of IIS you
could host ASP.NET inside your service. Currently you must also supply an
HTTP server, but you can download Cassini for this. Just add a reference in
your service to Cassini.dll and start a server an unused port of your
choice.

http://www.asp.net/Projects/Cassini/Download/Default.aspx?tabindex=0&tabid=1

In .NET 2.0 you will be able to use the same HTTP server stack that IIS uses
in a process of your choice. So you will have all the performance and
security of IIS, without having to run your application under IIS.

http://msdn.microsoft.com/msdnmag/issues/04/12/ServiceStation/default.aspx



David
 
Thanks David, that was a very good post. Cassini seems like a good idea
untill .NET 2.0.

However, the ideal choice for development, performance and security
remains to do everything in the ASP .NET Web Application. I need to get
some information concerning that. I know it is possible because I have
tried it, but only for a short period of time. I simply need some sort
of documentation concerning this that would help me make a descision;
maybe an MSDN article that would compare Windows Services to Web
Applications. Or maybe an an article by someone who has done this
before.

Thanks guys
 
Untitled said:
Thanks David, that was a very good post. Cassini seems like a good idea
untill .NET 2.0.

However, the ideal choice for development, performance and security
remains to do everything in the ASP .NET Web Application. I need to get
some information concerning that. I know it is possible because I have
tried it, but only for a short period of time. I simply need some sort
of documentation concerning this that would help me make a descision;
maybe an MSDN article that would compare Windows Services to Web
Applications. Or maybe an an article by someone who has done this
before.
Click to expand...

The problem is that the ASP.NET process model doesn't really support this.
Your application is not started automatically when IIS is started. It only
starts when the first HTTP request is made. So you must have a mechanism
to "tickle" your application every time IIS restarts. Furthermore you must
make sure that IIS never recycles your application, which it may do on
regular intervals or on reaching certian memory thresholds.

David
 
Another question comes to mind from the Cassini post by David. Even if
I did use Cassini. How would I host ASP .NET inside my Windows Service?
ASP .NET runs under its own service.

Mark
 
I am aware of these problems and I do have a "tickling" system that
should garantee both those things.

I'm looking for other potential problems, or live examples of this in
action. Our company cannot take such a blind risk. Strangely enough i
have found NO documentation or articles ANYWHERE concerning this.

ASP .NET does have timers. It is possible to start your own threads in
ASP .NET. Everything I want to do seems possible.

The only question is "Can I really do all these things in ASP .NET and
expect it to work just the same? Or is there something i'm unaware of?
Is there something else that is different between a Windows Service and
an ASP .NET Web Application that i do not know about"

Thanks Guys you have been really helpful

Mark
 
The only question is "Can I really do all these things in ASP .NET and
expect it to work just the same? Or is there something i'm unaware of?
Is there something else that is different between a Windows Service and
an ASP .NET Web Application that i do not know about"
Click to expand...

You can hammer a nail with a screwdriver, but it's a lot harder to do.
You're describing a Service, regardless of what tools you used to build it.
It should be built as a Service.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Neither a follower nor a lender be.
 
Well its not just a Service. It's also a Web Service and a Web
application. I need to somehow have all three in one.

Either i'm able to make my Service a Web Service and a Web application,
maybe using Cassini as David described. Or i'm able to make my Web
application a Service as i'm suggesting.
 
Untitled said:
Another question comes to mind from the Cassini post by David. Even if
I did use Cassini. How would I host ASP .NET inside my Windows Service?
ASP .NET runs under its own service.
Click to expand...

Cassini.dll allows you to host ASP.NET in your own service. You could not
run the Cassini web server on the same port as IIS, of course.

Here's a discussion of hosting Cassini.dll in a windows service:

http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=560232

David
 
A Swiss army knife has quite a few tools in the same package. However, the
nail clippers are not good for carving.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Neither a follower nor a lender be.
 
I read the posts. I understand how it is done. But I don't see anything
about NOT having the ASP .NET process run on its own. It still has to
be its own process running under its own memory space. This means I
cannot share objects with the Windows Service except through remoting.
This in turn means, when the ASP .NET recieves thousands of datasets
from my clien applications they have to be serialized again to be sent
to the Windows Service (because the windows service is the one doing
all the work). This also means whenever the user makes changes to data,
the changes have to go through remoting to my windows service and then
to the database. And finally, this also means that though I have lots
of data loaded in memory on my windows service, my ASP .NET Web
application still has to query the data from the database, or through
more remoting calls.

These are the things i'm trying to avoid.

Thanks again guys, I really apreciate it

Mark
 
Untitled said:
I read the posts. I understand how it is done. But I don't see anything
about NOT having the ASP .NET process run on its own.
Click to expand...

If you write your own windows service and reference the cassini.dll, as
described in that post, ASP.NET will be running in your service process.
You will be able to share objects between ASP.NET and your service. The
only wrinkle is that ASP.NET will be hosted in a seperate AppDomain. You
can modify the cassini code to return your main service class a reference to
the created AppDomain and start the rest of your service code in that
AppDomain too. Then you won't have to marshal between the AppDomains.

Just add the following method to Cassini.Host.cs

public System.AppDomain GetDomain()
{
//Host is MarshalByRef and lives in the web app's AppDomain
//so this call is marshalled and run on a thread in the other AppDomain
return Thread.GetDomain();
}

And this to Cassini.Server.cs

public Host GetHost()
{
return _host;
}


Then you can get the AppDomain for your web application with

Server.GetHost().GetDomain()

And you can fire up your service types over there.

David

David
 
Apparently, even though I have access to the Domain i don't think i can
access its contents.

"Code running in one application cannot directly access code or
resources from another application. The common language runtime
enforces this isolation by preventing direct calls between objects in
different application domains. Objects that pass between domains are
either copied or accessed by proxy."

<http://msdn.microsoft.com/library/d...uide/html/cpconapplicationdomainsoverview.asp>
 
Untitled said:
Apparently, even though I have access to the Domain i don't think i can
access its contents.

"Code running in one application cannot directly access code or
resources from another application. The common language runtime
enforces this isolation by preventing direct calls between objects in
different application domains. Objects that pass between domains are
either copied or accessed by proxy."

<http://msdn.microsoft.com/library/d...uide/html/cpconapplicationdomainsoverview.asp>
Click to expand...

Right, but with a reference to an AppDomain you can create an instance of
any MarshalByRef object in the AppDomain using
AppDomain.CreateInstanceAndUnwrap.

You would implement your main service class as a MarshalByRef object, put a
single .Run method on it, create it using AppDomain.CreateInstanceAndUnwrap,
and the hit Run. It will run in the target AppDomain.

http://msdn.microsoft.com/library/d...ppdomainclasscreateinstanceandunwraptopic.asp

David
 
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