ExamGuru IT/.Net Guru : Building A Service on ASPFriends.com 'ngfx-services' list

.NETGURU

Building A Service

Messages

Related Types

This message was discovered on ASPFriends.com 'ngfx-services' list.
Responses highlighted in red are from those people who are likely to be able to contribute good, authoratitive information to this discussion. They include Microsoft employees, MVP's and others who IMHO contribute well to these kinds of discussions.

Jim Davis

I tried posting this to ASPNGFreeForAll but received no really qualified
replies.
I am posting it here hoping to get a little direction.

This article seems to really hit my target end result.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguidnf/ht
ml/cptskCreatingServiceProgrammatically.asp
Does anyone know the best way to keep a service in loop?
Force it to re-run a script without being restarted.

I have done some research under the requested namespace for automation, but
only found information that confused me a bit. I don't have the resources
to go through this namespace to build something from scratch. I have seen
how easy it is to take a class file and turn it into Web Service, I was
hoping that there was similar way to create a ServiceProcess the merely ran
a piece of Code on a designated timed interval (3 minutes). And don't you
have to install services like this on the server?

Does anyone have some sample code regarding this?

Thanks,
Jim Davis

-----Original Message-----
From: Arnold, Jim [mailto:Click here to reveal e-mail address]
Sent: Friday, October 12, 2001 10:26 AM
To: aspngfreeforall
Subject: [aspngfreeforall] RE: Automation .NET

Look at System.ServiceProcess.

Jim

-----Original Message-----
From: Jim Davis [mailto:Click here to reveal e-mail address]
Sent: Friday, October 12, 2001 3:15 PM
To: aspngfreeforall
Subject: [aspngfreeforall] Automation .NET

I am writing an app that will rely on some sort of automation to be run
independently off the server. It needs to be more consistent then just
placing it in the default Page_Load as to be run whenever accessed by an
Anonymous user. I was thinking of WSH but I need the ability to manipulate
a Data Set. Is there anything in ASP.NET that mimics WSH and it's ability
to become a scheduled service running in the background?

Thanks,
Jim Davis

Thanks,

Jim Davis

Reply to this message...

Mitch Denny (VIP)

Jim,

There are a number of good samples in the quickstarts
that come with the Framework SDK, you can find them
at http://docs.aspng.com/QuickStart/, more specifically
they have some examples of services as the following URL:
http://docs.aspng.com/quickstart/howto/doc/simpleservice.aspx

Just to short circut alot of reading which probably
needs further explaination anyway, a service is already
running in a loop. All you need to do is find a way to
trigger your execution periodically. Take a look at
the following code:

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.ServiceProcess;
using System.Timers;

public class Sandpit46Service : System.ServiceProcess.ServiceBase {

    private Timer timer = null;

    public Sandpit46Service() {

        this.ServiceName = "Sandpit46Service";
        this.timer = new Timer(5000);
        this.timer.Elapsed += new
ElapsedEventHandler(this.ticker_Elapsed);

    }

    protected override void OnStart(string[] args) {

        this.timer.Start();

    }

    protected override void OnPause() {

        this.timer.Stop();

    }

    protected override void OnContinue() {

        this.timer.Start();

    }

    protected override void OnStop() {

        this.timer.Stop();

    }

    private void ticker_Elapsed(object sender, ElapsedEventArgs e) {

        EventLog.WriteEntry(
            "Sandpit46Service",
            "Elapsed",
            EventLogEntryType.Information,
            0
            );

    }

    public static void Main() {

        System.ServiceProcess.ServiceBase.Run(new
Sandpit46Service());;

    }

}

Sorry for the undocumented nature, but I will explain
more about it here. Notice that the class that inherits
from ServiceBase has a private instance of a Timer object,
and in the constructor I attach an event handler to
its elapsed event.

The timer is configured (in this example) to go off every
5000 milliseconds, causing the "timer_Elapsed" event handler
to be executed. This is the sort of behaviour that you
are after right? Just at a larger time interval (180000
milliseconds).

Notice how I haven't actually started the timer in the
constructor. A well behaved service doesn't do anything
until its requested to start, so you can see how I have
overrided the four methods:

    OnStart(string[] args);
    OnPause();
    OnContinue();
    OnStop();

And put appropriate code to start and stop the timer.

In the eventhandler, you could put in your own code
quite easily, or make it fire off an external script
using the System.Diagnostics.Process class. If you
wanted to get really tricky, you could create a
configuration file for the service that listed
classes in assemblies which implement an interface
you define and using reflection execute that code,
kind of a generic tool for timed execution of .NET
code. Of course that raises a whole heap of security
issues which can cause audit crews to escort you
from your employeers premises - but the option is
still there regardless.

Now, incase you don't know how to write one, here
is an installer class for this service so that you
can play around with it:

using System;
using System.Collections;
using System.ComponentModel;
using System.Configuration.Install;
using System.ServiceProcess;

[RunInstallerAttribute(true)]
public class Sandpit46ServiceInstaller : Installer {

    private ServiceInstaller serviceInstaller = null;
    private ServiceProcessInstaller serviceProcessInstaller = null;

    public Sandpit46ServiceInstaller() {

        serviceInstaller = new ServiceInstaller();
        serviceInstaller.ServiceName = "Sandpit46Service";
        serviceInstaller.DisplayName = "Sandpit 46 Service";
        serviceInstaller.StartType = ServiceStartMode.Manual;
        this.Installers.Add(serviceInstaller);

        serviceProcessInstaller = new ServiceProcessInstaller();
        serviceProcessInstaller.Account =
ServiceAccount.LocalSystem;
        this.Installers.Add(serviceProcessInstaller);

    }

}

Once again, I apologise for the undocumented nature
of the source, feel free to ask questions about it.

----------------------------------------
- Mitch Denny
- http://www.warbyte.com
- Click here to reveal e-mail address
- +61 (414) 610-141
-

[Original message clipped]

Reply to this message...

Jim Davis

Mitch,

Thanks for your reply.

I posted the question in hopes that I would get another stable alternative
to a (WSH) VBS file running from the command line and setup to do so by a
scheduling program. So my goal is only to get a script in an event that
re-runs every three minutes or so on the server. I only have a couple of
questions, when the service is running in a loop, does that mean that every
time the service loops it is actually restarting (OnStart/OnStop)? I
understand that any code needing to be executed should go under private void
ticker_Elapsed, but what if I need to run VB (your example seems to be in
C#)? How can incorporate a class file I build in VB? I haven't actually
built a Class File yet, but I have read some really good books and it
doesn't seem that hard. My only stumbling block would be importing that
Class into the Service, then by calling a method of the class during the
ticker_Elapsed my code will be executed in VB (which is the only language I
know).

Going over some of the links you sent me, does this...

http://docs.aspng.com/quickstart/util/srcview.aspx?path=/quickstart/howto/sa
mples/Services/ServiceApplication/SimpleService/SimpleService.src

...cover everything you did in your C# example? If so I do think I will
need the Class file after all.

Thanks for your reply,

Jim Davis

-----Original Message-----
From: Mitch Denny [mailto:Click here to reveal e-mail address]
Sent: Wednesday, October 17, 2001 7:48 PM
To: ngfx-services
Subject: [ngfx-services] RE: Building A Service

Jim,

There are a number of good samples in the quickstarts
that come with the Framework SDK, you can find them
at http://docs.aspng.com/QuickStart/, more specifically
they have some examples of services as the following URL:
http://docs.aspng.com/quickstart/howto/doc/simpleservice.aspx

Just to short circut alot of reading which probably
needs further explaination anyway, a service is already
running in a loop. All you need to do is find a way to
trigger your execution periodically. Take a look at
the following code:

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.ServiceProcess;
using System.Timers;

public class Sandpit46Service : System.ServiceProcess.ServiceBase {

    private Timer timer = null;

    public Sandpit46Service() {

        this.ServiceName = "Sandpit46Service";
        this.timer = new Timer(5000);
        this.timer.Elapsed += new
ElapsedEventHandler(this.ticker_Elapsed);

    }

    protected override void OnStart(string[] args) {

        this.timer.Start();

    }

    protected override void OnPause() {

        this.timer.Stop();

    }

    protected override void OnContinue() {

        this.timer.Start();

    }

    protected override void OnStop() {

        this.timer.Stop();

    }

    private void ticker_Elapsed(object sender, ElapsedEventArgs e) {

        EventLog.WriteEntry(
            "Sandpit46Service",
            "Elapsed",
            EventLogEntryType.Information,
            0
            );

    }

    public static void Main() {

        System.ServiceProcess.ServiceBase.Run(new
Sandpit46Service());;

    }

}

Sorry for the undocumented nature, but I will explain
more about it here. Notice that the class that inherits
from ServiceBase has a private instance of a Timer object,
and in the constructor I attach an event handler to
its elapsed event.

The timer is configured (in this example) to go off every
5000 milliseconds, causing the "timer_Elapsed" event handler
to be executed. This is the sort of behaviour that you
are after right? Just at a larger time interval (180000
milliseconds).

Notice how I haven't actually started the timer in the
constructor. A well behaved service doesn't do anything
until its requested to start, so you can see how I have
overrided the four methods:

    OnStart(string[] args);
    OnPause();
    OnContinue();
    OnStop();

And put appropriate code to start and stop the timer.

In the eventhandler, you could put in your own code
quite easily, or make it fire off an external script
using the System.Diagnostics.Process class. If you
wanted to get really tricky, you could create a
configuration file for the service that listed
classes in assemblies which implement an interface
you define and using reflection execute that code,
kind of a generic tool for timed execution of .NET
code. Of course that raises a whole heap of security
issues which can cause audit crews to escort you
from your employeers premises - but the option is
still there regardless.

Now, incase you don't know how to write one, here
is an installer class for this service so that you
can play around with it:

using System;
using System.Collections;
using System.ComponentModel;
using System.Configuration.Install;
using System.ServiceProcess;

[RunInstallerAttribute(true)]
public class Sandpit46ServiceInstaller : Installer {

    private ServiceInstaller serviceInstaller = null;
    private ServiceProcessInstaller serviceProcessInstaller = null;

    public Sandpit46ServiceInstaller() {

        serviceInstaller = new ServiceInstaller();
        serviceInstaller.ServiceName = "Sandpit46Service";
        serviceInstaller.DisplayName = "Sandpit 46 Service";
        serviceInstaller.StartType = ServiceStartMode.Manual;
        this.Installers.Add(serviceInstaller);

        serviceProcessInstaller = new ServiceProcessInstaller();
        serviceProcessInstaller.Account =
ServiceAccount.LocalSystem;
        this.Installers.Add(serviceProcessInstaller);

    }

}

Once again, I apologise for the undocumented nature
of the source, feel free to ask questions about it.

----------------------------------------
- Mitch Denny
- http://www.warbyte.com
- Click here to reveal e-mail address
- +61 (414) 610-141
-

[Original message clipped]

| [ngfx-services] member Click here to reveal e-mail address = YOUR ID
| http://www.asplists.com/asplists/aspngbeta.asp = JOIN/QUIT
| http://www.asplists.com/search = SEARCH Archives

Reply to this message...

Mitch Denny (VIP)

Jim,

Actually. I did wonder why you didn't just use a VBScript
with a Scheduler. In my experience that is pretty stable
if you have your operational processes in order.

On to answering your questions. When a service starts, the
executable containing the service code is run. This isn't
actually when the service is "started", what actually happens
is that the service is "put out there" and the operating
system tells it what to do (start, stop etc).

This is actually called a message loop. It is convienient
to thinking of a message loop as something akin to juggling,
the object is kept up in the air, but the juggling process
isn't actually changing its state.

In the same way, the message loop doesn't start or stop
the service, it just keeps it in the air. It is up to the
service control manager whether that service starts or stops.

The message loop takes messages from the operating system
and passes them to the service object, if the operating
system has no messages for the service, then the message
loop just sits there and spins its wheels - this is what
it is usually doing all the time.

I see that you found the VB sample in the SDK samples,
that should step you though creating a VB version of
pretty much the same service. The C# sample isn't the
same as the one in the SDK samples, but its pretty close,
at list similar in function.

VB.NET, C# and almost all other languages which currently
run on the .NET Framework are based on the concepts of
classes and objects, so it is highly likely that you are
going to need to write classes from time to time.

----------------------------------------
- Mitch Denny
- http://www.warbyte.com
- Click here to reveal e-mail address
- +61 (414) 610-141
-

[Original message clipped]

Reply to this message...

	System.ComponentModel.RunInstallerAttribute
	System.Diagnostics.EventLog
	System.Diagnostics.EventLogEntryType
	System.Diagnostics.Process
	System.ServiceProcess.ServiceAccount
	System.ServiceProcess.ServiceBase
	System.ServiceProcess.ServiceInstaller
	System.ServiceProcess.ServiceProcessInstaller
	System.ServiceProcess.ServiceStartMode
	System.Threading.Timer
	System.Timers.ElapsedEventArgs
	System.Timers.ElapsedEventHandler
	System.Timers.Timer
	System.Windows.Forms.Timer

ExamGuru IT Solutions - .Net Guru is owned and operated by ExamGuru, Inc., the man behind .Net Guru. If you're in the market for bespoke software or software consultancy, why not get him and his highly trained team to help? - www.examguru.net/ITCertification

Need Dot Net Interview Questions?
Ask ExamGuru, Inc. for advice and help on Passing .Net Interviews

.Net Projects
Best-of-breed application framework for .NET projects, developed by ExamGuru, Inc. and ExamGuru IT

Free .net Help
Commission ExamGuru, Inc. and his team for your next bespoke software project

FogBUGZ
The only bug tracking system carefully crafted with one goal in mind: helping teams create great software.

Awesome Tools
If you don't know about these, you're missing out... IT Certification Questions
IT Interview Questions
Free Oracle 10g Training
MCSE Boortcamp
Cisco Study Guides
Cheap Study Guides
Exact Questions
Dot Net Interview Questions
Oracle OCP
Cheap Travel
Designer Perfumes - Wholesale Prices
Free Programming Tutorials

	Copyright © ExamGuru, Inc. 2001-2006
	Contact Us - Terms of Use - Privacy Policy - www.dot-net-guru.com - www.examguru.net - www.oraclesource.net - www.itinterviews.net - www.examguru.net/ITCertification