I've created an SNMP listener application for one of our servers that runs as a service and passively listens for any SNMP message alerts sent from another server, and when one is received is sends out a page/email to appropriate staff. I followeda few online tutorials for setting up the application as a windows service since it needs to run constantly and won't require input/interaction from a user, or interaction with any GUI/desktop applications.
For some reason, when I install the application as a service, it installs correctly, but doesn't actually seem to be working. When SNMP messages are sent to the server nothing happens. However, in my app.publish folder there's an SNMPTrapper.exe application,and if I run that exe on its own, then everything works fine. For the time being I'm using a workaround so that the Onstart section of the code for the service basically just launches the SNMPTrapper.exe application, and when the service is stopped, it finds and kills the SNMPTrapper.exe process. At this point though, the service itself doesn't seem to be working/doing anything. It's essentially just a way to get the SNMPTrapper.exe application launched.
Does anyone know what the issue may be? In some of the tutorials I've read through they outline how to setup polling intervals for the service, but I don't think that would be applicable since this service will essentially just run constantly to listen for new messages, it won't need to check for anything at a regular interval.
Right now pretty much all of my code is executed in Sub Main() except for a few function calls.
Any help would be greatly appreciated.
You don’t state how you’re doing any of this. For a windows service you get two messages from the system: OnStart and OnStop. The job of OnStart is to set up all the required code to do the job, then exit. It doesn’t take part in the work so you need a Task or Thread setting up to do that. The Task or Thread should loop until it gets a message, passed by OnStop, that we’re done. If you want a service that you can test from the command line then your Main routine needs to do exactly the same setup, then wait for a key to be pressed before sending an OnStop.
(As an aside, you ARE remembering to start the service once you have installed it?)
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Forgive me if this is a stupid question, I'm fairly new to writing services. I've written a service that runs a timer and the timer code runs some checks to ensure our systems are up and running. It's written in VB.Net, framework 1.1. I then install the service using "sc create". The service works beautifully on the XP Pro machine that I'm developing on. However, when I install the service on a Windows 2003 server 64 bit, the service fails with error 1053 immediately. I put some debugging in to write to a text file as the first line of code in the OnStart function but even that doesn't run, so there must be a problem in the program starting up. Finally in desperation I created a brand new Windows Service in a new VB project in Visual Studio 2003 and compiled an empty service that merely declares and sets the value of a string variable in the OnStart function as follows:
Dim strTmp As String
strTmp = "hello"
Even that failed on the W2K3 server, but works fine on the XP dev machine.
The server has .Net Framework 1.1 installed and working, we use it in our CMS (written in ASP.Net 1.1).
The service runs as the local system account. I tried enabling interaction with the desktop but that didn't help. I ran Process Monitor and there are no access denied events. I emptied the Application Event Log, still doesn't work. No other events to help me out in the logs. Definitely using the Release build of the application. Permissions on the exe file are full control for System and for Admins.
Any ideas anyone? It must be something simple, but I'm damned if I can figure it out!
Thanks in advance.
#DavidHi, many thanks for the suggestions. I don´t think the first point is my problem, partly because the MS article is about stopping or pausing the service, mine fails on starting; but also because the service does not timeout, there is no 30 second wait, it fails immediately. Secondly, when you say add an exception handler to the service startup, do you mean the OnStart sub? I tried adding a debug file write in there, but I'll try adding an event log instead. Regarding the systems checks, it can't be that because the brand new empty test service I created shows the same behaviour and that does not do anything at all. You last point could be the key. My dev environment IS 32bit. I'll do some research on the corflags thing, or perhaps I can build a 64bit dev environment. Many thanks again, you've given me some new things to think about at least!
Ok, have found a workaround. I was putting my exe file in System32. When I put it in a different folder, created by myself, the service ran, albeit briefly. I then had to move the ini file and the log files that it reads/writes to that folder too, rather than System32, and all seems to work nicely. God knows why it doesn't like running from System32 but at least it works now! Thanks for the help guys.
This looks very similar to this question which might help you out:
Starting a windows service fails with error 1053
A couple of other things to look out for:
Make sure you don't have either of the following statements in your deployed service:
System.Diagnostics.Debugger.Launch
System.Diagnostics.Debugger.Break
You may need to run the service with an account other than Local System (depending upon the permissions required by your service).
The 1053 error is a timeout related to the service control manager waiting for the service to respond to your start request. There is a knowledgebase article that refers to managed service stop request issues specifically relating to Framework 1.1-based services, so it is not precisely describing your problem, but it may have relevance in your situation. The link is provided for your reference.
http://support.microsoft.com/kb/839174
The other suggestion I would make to further diagnose the issue is to determine whether the Start is failing due to a "hidden" exception occurring in your service's startup code; the start call would not see the exception and could make you think it was merely timing out.
I would suggest you add an exception handler to your service startup that does nothing more than log a message to the event log with the particulars of the exception if one is caught. That would at least give you an idea that something is going wrong specifically within the service, and give you more information than you have right now.
One last thought: Does the service check the systems you describe over a network connection? If so, LocalSystem won't have sufficient privileges to perform network access.
Good luck!
EDIT One other possibility:
Is your development environment/execuable 32-bit? You mention your server is 64-bit, so you may need to use the "corflags" tool that forces 32bit operation on your executable
corflags /32bit+ YourServiceExectubable.exe
The source for this information was the following SO post:
32-bit Windows services in 64-bit environment
**Unfortunately, it appears corflags is applicable only for 2.0 assemblies, and was designed for specifically this type of problem. **
I'm writing a VB.NET application that I want to load at Windows start up before the user logs in. It's going to run on a server and launch other process and kill and restart them as needed to get around a memory leak issue. It also needs to have a GUI to view the current status of the processes its managing.
Now, I can get the application to load when the user logs in but that's not very helpful because the server could reboot for some reason and no user would be logged on, but this application still needs to run in the background.
How do I do this? Do I need to write it as a service, or is there another way? I tried writing a WinForms app but it wouldn't load until after the user logs in.
You need to write a service. Also, probably best to write a second app that will interact with the service and provide a GUI to control what it does.
I have a Silverlight 4 application which talks to a 'manager' class, which talks to a WCF Service ( .net 4) , which uses the Microsoft.ApplicationBlocks.Data library to talk to my SQL database.
My issue is with exceptions not bubbling up to the Silverlight App.
What happens is, an insert to the database fails, creating an SQLException, this then throws the error further, to the generated service reference code used by the Manager, which, in the completed event handler, finds that the Error property is not null. This throws an event to the Silverlight app which displays a message to the user saying that an error has occured.
This works when I am locally debugging my application but fails silently when the appliaction is on the live/production server, no error message gets displayed.
If I generate the service reference from the wcf service running on the server (not locally), and use a local instance of my Silverlight App, it also works correctly which makes me think that the error is happening in the service reference (generated code) and Silverlight communication.
The service is hosted in a 'hand-coded' host application and the Silverlight app on the server is hosted in IIS. They both use http and not https.
I have scoured the Internet but found nothing that relates to this situation. I do not kill off objects, therefore preventing exceptions being returned to non-existant objects.
In short, the Manager correctly recieves and throws an event on my local system but not when deployed on the server.
WCF Experts needed please!
So, after some more fruitless searching, my collegue built a test app where he built a custom silverlight Fault Contract class based on this example:
http://msmvps.com/blogs/theproblemsolver/archive/2009/01/27/returning-exception-information-to-a-silverlight-client-through-wcf.aspx
Although this helped alot with getting the specific error from the service instead of the generic garbage Silverlight spews, we could still not get the error to display on the screen.
My previous guess that the communication was failing was incorrect. Instead, it was simply the fact that the result did not have any effect on the UI Thread. We used the Dispatcher to jump back onto the UI Thread:
Deployment.Current.Dispatcher.BeginInvoke(
() =>
{
//throw event to window which shows error window
}
);
which displayed the true error. I still do not know exactly why this was required for the app on the Production server but it worked fine on my localhost, in debug mode or not.
If anyone with more knowledge about the technicalities of this occurance reads this, please be so kind as to explain what really happened here.
I have a WCF service that I wrote, and I am trying to debugg some problems that I am having with it. I can attach to the process every now and again, but it is a very much hit or miss kind of thing. Why on earth is it so hard to attach to a process?
I clean the bin folders of my project before I compile, then copy the whole thing over to the server where my WCF process runs... Shouldn't that be enough to correctly load all the symbols?
To get the right process I run a utility, C:\Windows\System32\inetsrv\AppCmd.exe list wps...
It list all the WCF processes that are running on the server, I pick the process ID that is associate with my service.
To attach to the process I go the debug menu, click attach to process find the process ID that matches my service, and click attach to process.
Let me ask a general question, when you attach to a process do your symbols always load?
I want to pop a browser with a given url from within a windows service. Like so:
System.Diagnostics.Process.Start("http://www.venganza.org/");
Works fine when running in a console but not from within the service. No error messages, no exceptions, the Process.Start() command just seem to do nothing. It smells of some security issue, maybe something with the service properties and/or logon options? Annoying stuff this... Anybody? (Oh, and on windows 7/.NET framework 3.5.)
A service should never pop up anything to the user. Don't do this with a service.
You will problably need elevated rights to do this aswell. You will have to sign in as the user.
Even if you manage to do this, don't. This is not what services is ment for and it is really bad practise. If you really want someting to pop up, have a seperate process instead.
It is popping up, but on the Window Station associated with the service.
I would suggest that you tweak your design such that your service doesn't need to interact in this manner. There are ways to get it to appear on an interactive desktop (you'd have to cope with issues such as impersonating the relevant user, targeting the correct desktop if nobody is logged on or if more than one person is logged on, etc.)
Just on a side note Windows services aren't built for interactivity. They are used to process behind-the-scenes type stuff. However, have you tried enabling the Interact with Desktop option on the service itself?