Two weeks ago I needed a way to communicate a wcf service with a windows service running on the same computer. The windows service had to get data from a external source and share it with the wcf service (hosted in IIS) who had to give it when a client made a request. I chose to do that with ipc.
I done it and now the windows service is the ipc server and the wcf service is the ipc client. This goes well but I think I made a mistake doing this because to make it run right the windows service must to be executed with the ASPNET account, for this the ASPNET password account must be assigned and when I do that the IIS does not work correctly.
I am thinking on different alternatives, but in all of them the problem persists. Some ideas?
Edit:
What I needed was a system that made public, in a web service hosted in IIS, data gotten through telnet from another old system, what is a little unstable. How the response of this second system was slow I chose to put a process (the windows service) between the web service and the old system. The windows service had to save the data collected from the old system and when the wcf service asked it give it all at once through ipc.
Why does the windows service need to run as the ASPNET user? Is that because you're using an IPC connection that requires authentication from the caller?
Another alternative (if you have control over the windows-service code) would be to make that a WCF service as well (using a ServiceHost in the windows service). The IIS service could connect to the windows service using a NetTcp or NetNamedPipe binding if you need the IPC-like performance.
Why not just create another account with the same permission set of the ASPNET user which both the WCF service and your other service run under? That way, you have control over the password.
Ideally, the windows service should run as a WCF service, that way its easy for the client to communicate with it.
The next question is weather the 'client' needs to be a WCF service. If this client needs to serve other applications then it is appropriate, otherwise it may not be nessesary. I don't know enough about your system, so its up to you to decide what's best!
Related
I've gone through some tutorials on creating a WCF service. I'm using Visual Studio 2012. I got a very simple WCF Service Library (vb.net) and Windows Application (vb.net) communicating via WCF. That's a start.
However, my project requires I do the following:
My Windows Service - This is already an application that has it's tasks.
My Application - This is an application that is already developed as well.
I need the service to talk to the application. The service will need to send the following information to the windows application:
Status Updates
Metric Information (mostly integers for counts)
I need the application to send information to the service. It would need to send:
Reload Configuration command
Should be relatively simple, but I've never worked with WCF until today. So I have some questions...
Do I need to re-work my current windows service into a WCF Service?
Since it won't be in IIS, do I also create a WCF Service Library or do I roll this into the windows service somehow?
What is the best way to set up the different types of communication? (i.e., sending over specific metrics and reload commands)
Probably the main question is what components, in addition to my current windows service and application, will I need to make this work?
I hope that was clear :( I think I'm confusing it all... but I hope not
Your Windows service can host the WCF service. Similarly, if you want, your application can host a WCF service. The application could talk to the WCF service in the Windows Service, and the Windows Service's WCF could talk to the one in the application. Depending on the nature of the communication, you could also just use a callback channel to permit the Windows Service's WCF to call back to the application.
I suppose you should configure your WCF windows service to use named pipes. If your windows service is already built then the easiest way to do it would be to build another one as a WCF windows service and wrap the already existing functionality.
Hope I helped!
I have a Windows Azure Cloud Service with a single worker role. The worker role's App.config file specifies NTLM credentials should be used for the WCF authentication (Gist for all of this : http://goo.gl/wFCLv7 ).
Everything works as expected locally but when I deploy my CloudService to Azure, though I am prompted to enter my NTLM credentials (which are successfully audited according to the Windows Event Security logs of the Worker Role's machine which I RDP onto), invocations of the WCF service return null. (I don't know how to gather further debugging information)
After verifying with colleagues, sure enough the host machine for the WCF service is private, and not publicly facing - this probably explains why I can't query it from my application when it is hosted on the cloud, even with my Windows Authentication credentials.
How to I leverage non-public, NTLM-secure WCF services from Windows Azure? What do I need to change on the WCF server in order to consume the services from Azure? An easy answer may be to make the WCF host public - however the company is very fearful of "The Cloud" as it is -- is there a smaller alternative that can used for proof of concept?
Best,
networking/security/Azure noob
I have found some basic information about hosting a WCF service in a Windows service, but not much. All of my experience thus far with WCF has been in Web projects. I have a few simple questions.
I have a project which creates a windows service application. I have done a right click -> add WCF Service. This creates Service1.cs and IService1.cs.
I'm wondering why no SVC file is created in this scenario? When I add services to Web projects i get an SVC file which I can navigate to and use to consume the service.
Adding the service adds some configurations to the app.config under the services element. I'm seeing a default base address of
http://localhost:8732/Design_Time_Addresses/WindowsServiceName.services/WCFServiceName/
What does this mean? It's sort of an odd looking address. Am I supposed to change it to whatever I want?
Navigating to this address in a browser results in an unable to connect message. Does the windows service itself have to be running to talk to the WCF service?
How do I go about consuming this service from another application without an svc file?
I'm taking a guess on this first one, but I'm thinking the .svc file when hosting in IIS is to tell IIS, "Hey I have a WCF service here, please handle accordingly".
The base address is as it should be and yes you can change it if I'm not mistaken.
You can't hit the WCF service unless the Windows service is running, which is one of the dangers of hosting in a Windows service, because if the service dies somehow your WCF service is offline until you get the Windows service running again.
You consume the service the same way you do any other WCF service, just using that base address to get at it.
I have built a Windows forms application in C# using WCF for client -> server communication. I have recently begun toying with Silverlight and built a web front end for the application which still uses the same WCF service for web client to server application. What I'd like to do is have my WCF behind a firewall on a different machine and then build an "intermediary" WCF service which would live in a DMZ between IIS hosting my Silverlight client and the WCF box.
Essentially I want to seperate the WCF service which runs my windows forms application from also acting as a webserver. Does it make sense to build this intermediary app to increase security?
Can't see how that would increase security other than forcing connections to the WCF service to go through the DMZ ... but a straight forward http proxy server would do the trick.
The intermediary becomes more useful when you have a whole bunch of services and you want to centralize things like aunthentication, message logging in a single location or if you want to do some fancy (or not so fancy) message routing such as load balancing between a few services.
I am currently working on a silverlight client, making use of a web server, and an application server.
Most of the users sit within our firewall, so they do not have any problems accessing the WCF service running on the application server (through a Service.svc file).
However, some users will sit outside of our firewall, and only have access to the web server, and not to the application server (Where the WCF service is).
I am hoping someone could tell me if there is a way for the client to use the WCF service on the application server, through the web server, without rewriting the WCF service on the web server, and only relaying the calls through that server.
I hope this is a clear enough description of what I need.
Thanks
Sounds like what you want is a router service. Unfortunately, there's nothing built-in into WCF to do that (at least until .NET 4.0 with its RoutingService.).
You can certainly build it yourself, either by building a specific, one-off routing service (i.e. you implement the same contract and manually forward each operation to the service inside the firewall), or by building a generic, reusable routing service.
If you choose the second option, a couple of articles might help get you started.
Rather than have your Silverlight clients accessing the application server directly, route all the requests through a proxy service on the web server.
An example of this is the "Cross Domain Proxy" pattern.