Can someone help me in understanding the role of self-hosting in WCF?
Is this only for testing and development purpose? or can this also be useful any sort of real time application??
Why do we actually need service if we self-host it and limit it to a application?
WCF can be self hosted as a windows service (like what SPereyaslov suggested) or as an IIS service. The reason to host the WCF program (or any program) as windows service is so that the program starts and runs no matter who is logged on. In fact, if you have your program running as a windows service, the service can restart automatically if the server is restarted. That's the advantage.
Your question: Why do we need to make code as service when we have both client and service on the same machine? You don't need it to run as a service if both the client and web service are on the same machine. You could run compile and run the WCF program as an executable, but in a normal commmercial environment, you wouldn't have the WCF program and client on the same machine.
For example, you can host WCF service inside Windows Service. I think this case more natural if you need only tcp binding without http binding
Related
I am creating a web app. I want to create a listening service (TCP) that listens continuously and updates web page according to that.
A Windows service or a WCF service?
At the end I just want a background service that listens on a socket continuously and update data in database. and when database is updated I will use signal r to show that in my page.
Right now I am trying with WCF but I am wondering if it can be done with Windows service also. And right now this application will work on LAN. But in the future, it can also be in the cloud.
First of all, it is important to understand that a Windows service and a WCF service are not the same.
A Windows service is a specialized executable that runs in the background on Windows.
A WCF service is a specialized piece of code that exposes some functionality through a well-defined endpoint. It does not run on its own, but instead must be hosted by some parent process, like IIS, a desktop application, or even a Windows service.
In thinking about the problem you've described, I suppose the most fundamental question to ask is whether or not you have control over the data that will be received via the TCP connection. WCF is built on the notion of the ABCs (Address, Binding, and Contract), all of which have to match in order to facilitate data exchange between WCF endpoints. For example, if you wish to expose a WCF endpoint via IIS that accepts TCP connections from some remote WCF endpoint, the remote WCF endpoint needs to send data to your IIS-hosted WCF endpoint using the agreed-upon data contract. Absent that, WCF will not work. So, if you cannot define the data contract to be used between WCF endpoints, then you'll need to find another option. An option that will work is to open a TCP listener within a Windows service, process the data as it is received, update your database, and listen for more data.
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By way of example, I work on a project that has a front-end desktop application that communicates with a back-end Windows service. We build both the application and the Windows service, so we have full control over the data exchange between the two processes. At one point in time, we used WCF as the mechanism for data exchange. The Windows service would host a WCF service that exposed a NetNamedPipeBinding, which we later on changed to NetTcpBinding to get around some system administration issues. The application would then create its own endpoint to communicate with the WCF service being hosted within the Windows service.
This worked fine.
As our system got more mature, we needed to start sending more and more information from the Windows service to the application. If I recall correctly, I believe we experimented with streaming within WCF and concluded that the overhead was not something we could tolerate. So, we used WCF to exchange commands and status information between the application and the Windows service, but we simultaneously used a TCP socket connection to stream the data from the Windows service to the application.
This worked fine.
When we got a chance to update the Windows service software, we decided that it would be better to have a single communication mechanism between the Windows service and the application. So, we replaced WCF altogether with a TCP socket connection that uses a homegrown messaging protocol to exchange information in both directions - application to Windows service and Windows service to application.
This works fine and is the approach we've used for a couple of years now.
HTH
I am hosting a handler inside of a IIS web application. Is this a good solution ? Or Should I Hosting a handler in windows service application ? Which solution is better? What is recommended and what is more performance ?
I use SqlTransport in my configuration.
There are many factors that can effect how you choose to host your endpoint(s). For example
How you want to scale your site / handlers
What permissions can be granted to your web site process
How an IIS reset can effect your handling code
But in general... Host the bus in both the Web Application and a Windows service.
The web application handles incoming http requests, translates those requests to messages and places them on the bus via a Send.
The Windows service takes message off the bus and does the actual handling/business processing.
Some useful links that may guide you to the best solution for you circumstance
Hosting documentation http://docs.particular.net/nservicebus/hosting/ which contains some information on hosting in a web application
Windows Service Hosting http://docs.particular.net/nservicebus/hosting/windows-service
A showcase sample that uses a similar design as i described above http://docs.particular.net/samples/show-case/on-premise/
Web related samples http://docs.particular.net/samples/web/
Implications of Publishing from Web Applications http://docs.particular.net/nservicebus/hosting/publishing-from-web-applications
If you need to send messages from your web application then the only solution is to host NServiceBus in IIS, With IIS you shouldn't be publishing events from IIS.
Take a look here for more details
HTH
I am in a stage of using SignalR in my project and i don't understand when to use Self hosted option and when we should not use. As a example if I am willing to host my web application in server farm,
There will be separate hosting servers
Separate SignalR hubs in each IIS server
If we want to broadcast message into each client, how this is working in SignalR
The idea with SignalR running in multiple instances is that clients connected on instance A cannot get messages from clients connected to instance B.
(SignalR scaleout documentation)
However, when you scale out, clients can get routed to different
servers. A client that is connected to one server will not receive
messages sent from another server.
The solution to this is using a backplane - everytime a server recieves a message, it forwards it to all other servers. You can do this using Azure Service Bus, Redis or SQL.
The way I see, you use the self host option when you either don't want the full IIS running (because you have some lightweight operations that don't require all IIS heaviness) or you don't want a web server at all (for example you want to add real-time functionality to an already existing let's say forms application, or in any other process).
Be sure to read the documentation for self-hosting SignalR and decide whether you actually need to self host SignalR.
If you are developing a web application under IIS, I don't see any reason why you would want to self-host SignalR.
Hope this helps. Best of luck!
I have a nettcp service which I have to host. I have three options -
IIS 7
Windows Service
A console application
I would be grateful if anybody could give some valuable thoughts on which option is better vis-a-vis other one.
Here are some of my observations:
IIS 7:
Pros:
Ready made hosting environment inside IIS
Will work with pretty much any hosting environment
Cons:
HTTP Only
Configuration slightly more complex
WAS:
Pros:
Ready made and familiar process model to that of IIS
No dependency on IIS
All protocols supported
Cons:
Not all shared hosting environments will support non-http protocol bindings or unusual port numbers.
Configuration slightly more complex
Windows Service:
Pros:
Starts when windows starts
You can start/stop the service via the service control manager
All protocols supported
Cons:
Some extra steps to deploy/re-deploy (installutil)
You need some extra boilerplate code to support the service implementation
Not ideal if you can't have access to the server to install (e.g. shared hosting)
Console Application:
Pros:
Fast and simple to deploy for testing purposes
All protocols supported
Cons:
You need to be logged on to start the process
Loss of session or machine shutdown will kill the service
Console/RDP access required
We have two servers, both are containing a local application connecting to local web service, applications and services are identical on both servers.
One of the servers work just fine,
The other one is just dead, I have impression the the security configuration are different on those servers.
What prevents an application X from connecting a web-service, given that another application y on the same server can connect to it. and X is a windows service.
What I should check, what is chances?
Thanks
Check if there is any firewall that might need to some ports opened up.
Could there be any kind of AntiVirus or similar set up on one of the servers?
Basic troubleshooting of loosely-coupled applications means independent testing/verification of those services.
Can you access the web service locally through a different application, i.e. a web browser? If you can't reach the service through the browser, then the server configurations (at some level) are not identical.
Only after you're certain the service is reachable should you look into issues with the windows service.