I am trying to set up an R.net WCF service as a server to run R commands on.
I have set up a test WinForms application where everything works.
This is how I use it:
void init()
{
SetupPath()
engine = REngine.GetInstanceFromID("test");
if (engine == null) engine = REngine.CreateInstance("test");
engine.Initialize();
}
...
results.Add(engine.Evaluate(command).AsCharacter().ToArray());
I created an equivalent WCF service which should work exactly the same;
REngine.CreateInstance() returns a valid REngine object,
engine.Initialize() silently crashes my service. Try-Catch section is ignored so I cannot see what exactly is happening.
What is the correct way to use R.net within a WCF service?
What could be the reason of different behaviours?
Where can I see detailed logs of the crash?
Service calls which don't use R.net complete successfully.
Both winforms test application and WCF service are 64 bit (i need them to be). (I did not manage to set up a 64-bit IIS express application, so am using IIS instead).
I did not manage to find the reason of the problem, however, switching to R.NET.Community package did the trick.
Related
I've created the WCF service and some simple WPF application consuming it. When I'm running the project from within Visual Studio, the WCF Test Client opens and the application works just fine, method defined in service work.
But I need to host this WCF service in a Windows Service. I've followed this, installed the services using Installutil.exe and the ran the service. Everything went fine, it's working.
Yet, when I'm trying to open the executable file with WPF application directly from the debug folder of the app, I'm getting this error:
zad8. has stopped working
After choosing the option to debug it with new instance of VS I get
XamlParseException occured in PresentationFramework.dll
The stack trace shows something like:
connection can't be started, because the target computer is actively refusing it
Do you have any idea what could go wrong?
Fortunately, I've managed to come up with solution. I think I should post it, maybe one day it will help somebody:)
I actually did two mistakes, but one of them was unfortunately caused by the mentioned tutorial (here) in connection with my temporary blackout.
In step 5, point 8 of this tutorial, there's an example of overriding OnStart() method:
protected override void OnStart(string[] args)
{
if (myServiceHost != null)
{
myServiceHost.Close();
}
myServiceHost = new ServiceHost(typeof(Service1));
myServiceHost.Open();
}
Beware, that Service1 is ambiguous in this context, because it's name of the Windows Service project class as well as the name of WCF Service class. It should be written with fully qualified name (here it is WcfServiceLibrary1.Service1). In my case, the service name was different, and I just put the Service1 in there in a hurry. Anyway..
In case, someone has it all behind and still encounters the same problem (with app stopped working), I think that you should try open the project in Visual Studio and try to debug the client consuming application as a new instance (right click on the project-> Debug -> Start as new instance...).
It might seem trivial, but when u hit F5 or Ctrl+F5 then even if u have only those project set as startup project, VS will host it's client anyway. In my case it did matter, because I needed to use isolation storage file. And as it was kept on the service side, then I had this file created in IIS server created by VS. Somehow, my method of creating such file had set FileMode.Open() and it was causing the crush, because in Windows Service it didn't exist and the new one couldn't be created and that was neccessary to run it correctly.
What's more it just showed me that this question couldn't be answered properly, cause the data I've provided was not enough and it was delicate.
Cheers:)
I have a simple web service that looks something like this:
[WebMethod]
public OrderForecastItem GetOrderForecast(int shipTo, string catalogName, bool showPricing)
{
return OrderForecastManager.GetOrderForecast(shipTo, catalogName, showPricing);
}
I'm calling it from another place in a fairly simple way:
using (OrderForecastWS.OrderForecastWS service = new OurSite.Web.Reporting.OrderForecastWS.OrderForecastWS())
{
OrderForecastItem orderForecastItems = service.GetOrderForecast(2585432, "DENTAL", false);
}
After some gymnastics to get the systems to understand that I'm talking about the same type of objects on the client and server sides (I had to open the Reference.cs file inside my Web References, delete the generated OrderForecastItem and add a link to our real OrderForecastItem), the system runs and attempts to get the item.
Unfortunately, it now bombs during the service call, claiming:
Exception There is an error in XML document (1, 1113).(InvalidOperationException)
I can go to the web service in a browser, put in the same values, and I get a seemingly valid XML response. (It looks okay to me, and I ran it through the XML parser at W3Schools, and it cleared it.)
I think the numbers in the error are supposed to be the line and character number...but the browser seems to reformat the xml document, so I can't easily see what the original (1, 1113) location is.
I don't see an easy way to intercept the response and examine it, since it seems to be blowing up as soon as it gets it.
How can I debug this?
If you control the service, you can step into it. If it is a part of your solution and hosted in VS WebDev on your local box, just F11 from Visual Studio, if service is hosted remotely (eg by IIS on other computer) run remote debugging tool on service host msdn, and then you will be able to step in to the service remotely.
By the way, you can tell Visual Studio to re-use objects from referenced libraries for types from the service: just pick configure Service Reference from service context menu and tell which libraries to re-use.
On second thought this error may happen if returned XML could not be deserialized into your business object. May happen when class is changed on either side, or you are trying to use different version of business library than service is using.
If you use Firefox, I'd recommend Firebug. You'll be able to easily view the response from the website in its original format, which might get you closer to the line and position you're looking for.
I need to change my unit test from local to remote tests and so far I thought that all I had to do is change UrlToTest to point to another server... But VS keeps on insisting to create a Development Web Server instead of using the one that is already running.
So after reading some docs my question actually is do I have install Test Controller and Test Agent on both remote and local computer or what? What if the WebService is on Linux...
Note that I don't want to debug the application that I'm testing. I simply want tests to be executed for a WebService that is already running, that is deployed.
I probably should mention that all my tests consists of WebService calls and some checks like this:
[TestMethod()]
[HostType("ASP.NET")]
[AspNetDevelopmentServerHost("MainProjectName", "/")]
[UrlToTest("http://servername:port/websitename/TestingOnlyWebForm.aspx")]
public void LoginEmptyDataTest()
{
IUserService userService = CreateIUserService();
string email = "";
string password = "";
ReturnMessage<User> actual;
actual = userService.Login(email, password);
Assert.AreNotEqual(true, actual.Status);
Assert.AreNotEqual("db_error", actual.Info);
}
But I have also more complicated tests in which I change some data and send it to another WebService and so on.
Note that UrlToTest previously was pointing to localhost at which point it works but starts a developer server which is not what I want.
What you are trying to is not possible. All that generated unit test is trying to do is to run the test locally on the machine either using the development server by specifying AspNetDevelopmentServerHost or by using local IIS, when AspNetDevelopmentServerHost is not present.
If you want to test remote services right click your unit test project and add a service reference. Point to your service give it a namespace, say Services, and generate the proxies. Once you have the proxies generated just instantiate them and call the methods. Also remove all the unneeded attributes from your test. Your test should roughly look like this:
[TestMethod]
public void LoginEmptyDataTest()
{
using (var userServiceClient = new Services.UserServiceClient(
"BasicHttpBinding_IUserService",
"http://someremotehost/userservice.svc"))
{
var result = userServiceClient.Login("user", "password");
// asserts go here
}
}
This may solve your immediate problem however you should re-think what you are doing as #eglasius said. what happens if the code you call changes state internally? Next test might fail because of that so you need clean-up strategies otherwise your tests will be very brittle and you'll end up ignoring them.
Update: passing an address at run-time. Change the first parameter to whatever enpoint configuration name you have in your config file.
I'll take a stab in the dark at this one because I did something similar recently.
In my case my test project referenced the service project to provide visibility of the service and data contracts the Web Service implements and consumes.
To resolve this - though it can be ignored - move the contracts to a new project. Then have the service and test projects reference the new project, and remove the test projects' reference to the service.
Hope that makes sense!
Once the reference is removed, VS will no longer feel the need to start up your service when you run your tests.
You can disable the startup of the Service Host in the Project settings of your WCF Service Project. Right Click - WCF Options - Uncheck "Start WCF Service Host when debugging another project in the same solution".
You really have to consider the nature of what you're trying to achieve here.
It's hard to tell exactly what you're hitting of the code. I have the impression, you have is a website that calls a web service. You're testing the client code in that context, instead of just testing the service.
If that's the case, remove the attributes and point the url to the correct service like UrbaEsc guided you to. If you don't remove the attributes, you're running the calling code in the context of the site.
Even if the above is not the scenario, and based on what you replied to UrbanEsc in the comments, you'd then be testing an external call to the webservice initiated from the same site process.
You said:
"Found it, but VS still starts something on localhost and then trys to reach external server... Seems like VS is just not designed for real remote testing of webservices"
Read the above. I'd say you need to better understand what you're enabling. You can certainly test remote web services, like you can do pretty much anything you can code. You do that from client code that knows nothing different that what any other external client of the service would know. Support doesn't stop there, as you can do load testing of the service.
Note that what you're doing aren't unit tests, these are integration tests. Or depending on the scope of your system, full system tests.
I have a WCF service that is hosted on a c# console application. Is there a way to restart this service, preferably by calling an endpoint in the service itself (ex. myService.Restart()).
Thanks
I have to do something similar when I perform an automatic update of a remote WCF service. In your Restart() method, close the host:
try
{
host.Description.Endpoints.Where(x => !x.Address.ToString().EndsWith("MEX")).ForEach(endpoint => _log.InfoFormat("Closing {0}", endpoint.Address));
host.Close(TimeSpan.FromSeconds(5));
}
catch (Exception)
{
host.Abort();
}
I wait for my update to apply, and then after a success or failure, I re-open the host using the same code I used to start it in the first place.
If you just wanted to restart immediately, you could just call host.Open(), or you could set up a timer to call it, etc.
try
{
host.Open();
host.Description.Endpoints.Where(x => !x.Address.ToString().EndsWith("MEX")).ForEach(endpoint => _log.InfoFormat("Host opened at: {0}", endpoint.Address));
}
catch (Exception ex)
{
_log.Error("Unable to open host.", ex);
}
To answer my question, I have solved the problem by doing the following:
Separating the code that loads the DLL files from the WCF service code into another class library project
Create an interface with the same method signatures as the ones that load DLL files in the new project (this interface is used by both projects now)
In the web service, load the other project in a new application domain. This way the DLL files are locked by the new application domain not the default.
If I want to update my nunit DLL files now, all I have to do is unload the application domain from the web service, update the files and finally create a new application domain.
AppDomain remoteDomain = AppDomain.CreateDomain("New Domain");
IClass1 class1 = (IClass1)remoteDomain.CreateInstanceFromAndUnwrap(
"Test1.dll", "Test1.Class1");
Note: IClass1 is the common interface between the projects.
you definitely are not going to be able to 'restart' a faulted service from calling that same service itself. In theory you could host 2 services in the same process. put the one you want to be 'restartable' in a public static variable and restart it within the other service. The problem would be restarting the restarter service if it faults... :) and you definitely want 'administrator-like' restrictions on your restarter service so unauthorized users can't do it.
It's a bit kludgy, but I suppose you could expose a callback on your service that the host could attach to and take appropriate action when it's triggered. That would give your host the ability to decide what a "restart" really means and how it needs to be executed. More importantly, it lets your decide whether it should do something extreme like spawn off a watcher process and then off itself or gracefully trash and reinstantiate your service (preferable).
Mmmmmm... kludge....
You cannot ask a service to restart itself. Consider a windows service (a service hosted in windows provided container) which has a RESTART functionality. Here RESTART functionality is provided not by the service but by the container. The container controls how to stop the service and start it.
Similarly in your case, you should try to look out for options if your container can provide the functionality you need. Since you want to control it remotely, the container should also be available remotely, which cannot be possible if the container is a console application. Instead it has to be another web service or web application.
I have a project that is deployed to production as a windows service. However for local development purposes it would be useful to run it as a console application. At the moment I have a class Called ReportingHost that provides my core functionality, And a class called ReportingServiceHost that inherits from ServiceBase and allows me to run the application as a service. There is also a program class with a main method that calls ServiceBase.Run on my ReportingServiceHost.
I think I need to write a ReportingConsoleHost class that allows me to run the functionality in a console. Then I need to modify my Main to react to a command line switch and choose one or the other. These are the two bits I am having trouble with.
I have had a look at this and attempted to use that code but my app exits immediately, it doesn't show a console window and it doesn't wait for Enter before closing.
Part of the problem is that I dont have a deep understanding of how these things work. a definitive pattern for splitting my functionality, my two different ways of running that functionality, and a main method that chooses one of these ways based on a command line argument is what I am hoping to achieve.
I suspect your test project was configured as a windows exe, not a console exe. With a windows exe Console.ReadLine will return immediately.
To have a console exe that works both as a service and at the command line, start it as a service project (in Visual Studio) - and add a check on Environment.UserInteractive - i.e.
static void Main() {
if(Environment.UserInteractive) {
// code that starts the listener and waits on ReadLine
} else {
// run the service code that the VS template injected
}
}
You can of course also use a command line switch. I have example on microsoft.public.dotnet.languages.csharp that acts as:
an installer / uninstaller
a service
a console-mode app
depending on the switches
I have done this before by implementing a normal Windows Service (by deriving from ServiceBase), but putting a check in the main method to check for a command line argument.
If the args contain /console, start the console version, otherwise start the service.
Something like this:
internal class MyService : ServiceBase
{
internal static void Main(string[] args)
{
if (args.Length == 0)
{
// run as a service....
ServiceBase[] servicesToRun = new ServiceBase[] {new MyService()};
Run(servicesToRun);
}
else
{
// run as a console application....
}
}
}
My advise? Put all your logic for your service in a separate assembly. (A class library or DLL.) Then create one project as service which references your class library and puts the code to use as services. Create a second console project which also references your class library but which will make it available as a console application.
You would end up with three different projects in your solution but it does allow you to keep things separate. Actually, this would make it possible to extend your service in several other shapes too. You could, for example, create a 4th project as a web service and thus call your service from a web browser on a client system. Because the software logic is separated from the usage logic, you gain lots of control over it.
Be aware that a service will possibly run with more limitations than a console application. In general, services don't have network access by default, don't have a monitor assigned to them to display error messages and in general run with a limited user account or system account. Your service might work as a console yet fail as a service because of this.
There are already two good answers above - but I thought I'd post a link to Brian Noyes' Debuggable Self-Host Windows Service Project blog post - it talks about WCF but should apply to any 'Windows Service'.
The best thing is the sample code - if you can't figure out where the above examples 'fit', grab the complete project and see how it works. Thanks Brian!