I am starting a new webservice project which will be consumed by multiple consumer applications done in different technology like ASP, ASP.Net and PHP. I am planning to develop this service as a WCF service. I am new to WCF and I understand WCF is like umbrella tech which has all the features for developing a distributed SOA applications.
I would like to get your advice on whether my choice of opting WCF service over classic asmx service is correct. The consumer applications are existing application done different technologies as I said before. This service is a simple service that creates and updates user information in a centralized DB.
If my decision of choosing WCF is correct, then please let me know if there are any specific things I need to consider so that the existing application can consume my WCF service without any hiccups. In other words, I can provide a asmx service for this which they can consume directly without any issues (and currently they are consuming some of our asmx service. Since the current requirement is new I want it to be done with WCF). Likewise, the consumer should be able to consume my service like they consume asmx service.
I am asking this question because WCF provides additional features like security, etc. and hence the consumers should also follow the practice to communicate with the service.
Any advice is highly appreciated.
You probably want to use BasicHttpBinding in your WCF service and, although I'm not a PHP developer, I understand that PHP 5 has a SOAP library that can be used to create a service proxy based on the WSDL document exposed by the WCF service, assuming metadata exchange is enabled.
Related
I work in a company that is only using WCF and i am trying to introduce service stack. Now i understand we are better off using the service stackclients that wcf clients but for some of our stuff and to keep people happy that will not always be possible. Can anyone provide a basic example of a ServiceStack service that can be added as a client into a VS2012 project using the add service reference inside visual studio as you normally do for a WCF service? Basically is there a way to make ServiceStack seem like a WCF service to people that don't know about ServiceStack?
If i can show this i think i can convince my company to make the switch but if not it will be difficult as everything else is WCF based. We are already using the ServiceStack clients to hook into other online websites so it seems a good time to try to convince them to move to the service stack services and clients as long as they feel they can fall back to the WCF client if needed.
Provided you adhere to the SOAP guidelines and limitations in ServiceStack you should be able to add a Service Reference by pointing the client to the ServiceStack wsdl at /soap12, e.g:
http://servicestackbaseurl/soap12
You can also find a link to the soap 1.1/1.2 wsdl (and XSDs) on ServiceStack's /metadata page.
I am learning WCF,one of the benefits of WCF is that you can use WCF even the client and service are not in the same network.Can anyone explain why?
Why using normal asp.net services, .NET remoting or Windows enterprise service client and service have to be in the same network?
Another question is that does the client needs to have a service contract interface and data contract? I assume not ,but how the client understand the type returned from the WCF services?
Edit: Reflecting More comments
A primer on WCF (such as What Is Windows Communication Foundation?) is a good place to start. WCF can use SOAP to implement the contracts way down deep. WCF also uses a variety of communication facilities within windows (and any custom ones you want to create) so talking across machines is built in.
The very essence of contract (IMO) implies that this is present on both sides of the communication. In a pure .net cases I've usually put the contract definitions in separate assemblies and share them. In other places I've used WSDL to be the main contract definition so that the client and service share definitions.
Edit: Answering comments
You can knock up simple examples of communication in WCF easilyy (provided you know the basics of comms on windows including firewalls etc). However doing something custom is not easy but there are many many resources on the web and books to help you get there.
The books i used:
http://www.amazon.com/Programming-WCF-Services-Juval-Lowy/dp/0596526997
http://www.amazon.com/Essential-Windows-Communication-Foundation-WCF/dp/0321440064/ref=pd_bxgy_b_img_c
http://www.amazon.com/Inside-Windows-Communication-Foundation-Developer/dp/0735623066/ref=sr_1_1?ie=UTF8&s=books&qid=1252111759&sr=1-1
Another question on SO with a set of resources is "WCF for the Totally Clueless"
I don't know where you read that a benefit of WCF is that it allows the client and server to be on different networks. They can already be on different networks using .NET Remoting or DCOM (Enterprise Services).
The client does need to know the service contract and any other contracts required in order to use the service. This can be provided through WSDL or the Metadata Exchange Protocol (mex). If using .NET on both sides, then it is possible to share the contract assemblies, but this introduces a coupling between client and service.
Previous Microsoft technologies were designed for some specific needs in particular environment. For example ASMX Web Services were designed to send and receive messages using SOAP over Http only. .NET Remoting specific to Microsoft environment, no interoperability. But WCF is designed to send and receive messages using any format (SOAP as default) over any transport protocol i.e. HTTP, TCP, NamedPipes, MSMQ etc.
And your second question "but how the client understand the type returned from the WCF services?"
Its through proxy, client interacts with proxy which contains all the types etc.
You can find a good concepts and questions here for understanding WCF core concepts.
I am learning wcf but I have trouble understanding the benefits. Is there ever a time I would want to use traditional web services?
I read another thread with these benefits:
Opt in model for members using a certain attribute
Better security
No need to worry about binding (can't understand how this is true)
No need to worry about the xml
I read Programming WCF Services however this was an advanced book a bit like CLR via C#. I am now reading Learning WCF Services and will read Essential WCF (is recommended).
What would happen if I use a normal class to try to talk to a web/service reference? I know this sounds really naive, it's just my lack of experience in web services.
I am coding some WCF services so I am getting exposed to the specifics. They are interacting with a SOAP web service provided by my web host so I can get stats on my site. Is there anything wrong in this approach?
Thanks
WCF is a unified programming model for developing connected systems. What this means is that you use a single framework to develop service-oriented solutions. WCF allows you to keep your service implementation relatively unaware and care free of what's going on under the covers as far as how your service is consumed by clients and communication is handled. This allows you to take your service implementation and expose it in various ways by configuring it differently without touching your service implementation. This is the unified part. Without WCF, you have to get familiar with a framework specific for a particular communication technology such as ASP.NET asmx web service, .NET remoting, MSMQ etc and usually those frameworks impose on your service implementation and creep in such as using WebMethod attribute or having to derive from MarshallByRefObject object etc and you just can not take your service implementation and easily expose it over another communication stack. If I have a service that adds two numbers, why can it not be exposed over http or tcp easily without having to worry about low level details? This is the question in your post regarding binding. Binding allows you take a service and configure it so that it can be exposed over different transports and protocols using different encodings without ever touching your service implementation.
Is there ever a time I would want to use traditional web service?
Web service uses well defined, accepted, and used standards such as HTTP and SOAP. So if you want your service to be consumed by wide range of clients, then you would want to expose your service as a web service. WCF comes with pre-configured bindings out of the box that allows your service to be exposed as a web service easily: basicHttpBinding and wsHttpBinding. You may also want to consider RESTful services which is an architectural style that fits more natural with the HTTP model. WCF supports RESTful services as well
What would happen if I use a normal
class to try to talk to a web/service
reference? I know this sounds really
naive, it's just my lack of experience
in web services.
WCF service can expose the wsdl for a service just like ASP.NET asmx web service does. You can generate a client side proxy by simply adding a service reference to your client project. There is also a command line tool called svcutil that also generates the client side code that allows you to easily communicate with the service. The client side service class basically mirrors the service interface. You create an instance of the client side proxy for the service and then simply call methods on it just like any other .NET object. Under the covers, your method call will get converted to a message and sent over the wire to the server. On the server side, that message will get dispatched to the appropriate service method.
I hope this helps a bit.There are lots of online content such as videos on MSDN and channel 9 that you check out. The more you pound on it and expose yourself to it, the clearer WCF will get I am sure. Also, WCF is THE framework Microsoft recommends to develop connected system in .NET. The other technologies ASP.NET asmx, WSE, and .NET Remoting will most likely still be available going forward but may not be supported and developed further.
There are a number of existing approaches to building distributed applications. These include Web services, .NET Remoting, Message Queuing and COM Services. Windows Communication Foundation unifies these into a single framework for building and consuming services.
Here is a link from MSDN Why Use Windows Communication Foundation?
WCF is really the "new" standard and new generation of web service - and even more generally, communications - protocols and libraries for the .NET world.
Whenever you feel the need to have two systems talk to one another - think WCF. Whether that'll be behind the corporate firewall in your company LAN, whether it's across the internet, by means of a direct call or a delayed message queueing system - WCF is your answer. Mehmet has written a really nice summary of how WCF is the unification of a great many communication standards that existed in the Microsoft world before WCF.
I would think with the "Learning WCF" book, you should be a lot better off than with Programming WCF - that's quite advanced stuff already!
One of the mainstays of WCF is the architecture that you always talk to your service through a proxy - whether that service runs on the same machine using NetNamedPipe binding or halfway around the world in Down Under on a server - no difference, you always go through a proxy. That then also allows WCF to be so extensible - thanks to the proxy always being between the client (your application) and the service, it offers excellent ways of extending the behavior and the inner workings of WCF to your liking and needs.
WCF basically builds on SOAP communications - so interfacing and using existing SOAP services should be no problem at all. With the WCF REST Starter Kit and in the upcoming .NET 4.0 release cycle, WCF will also extend its reach into the REST style web communications, if that's ever going to be a requirement of yours.
All this really shows one of the biggest strenghts of WCF: it's a unified and extremely flexible and extensible communication framework, that can handle just about anything you throw at it. That alone is more than enough reason to learn WCF (which can be dauting at first, I agree!), and you won't regret the effort you put into this endeavor.
Marc
Have you a specific application you are writing for, or just getting your feet wet?
Google protocol buffers, is a very good choice of communications. John Skeet & Marc Gravell have both done C# implementations. See here
I am new to WCF and Web Services in general. What are the improvements that WCF brings to the table? Can anyone give a side-by-side example of a traditional web service and the same one written using WCF and point out the differences and advantages?
Duplicate question Moving ASP.net webservices to WCF
EDIT: Think i found the answer you where looking for a side-by-side code based comparison and even better it's from MSDN: Comparing ASP.NET Web Services to WCF Based on Development
There are several related questions:
Difference between aspnet web method and wcf webservice
Benfits of using WCF
Moving aspnet web services to wcf
However you asked for a side by side comparison in which case i think Sam's Wcf vs ASMX blog article is more what you are looking for.
Quoting ad-verbatim (let me know if i should just leave it as a link):
WCF vs. ASMX
Protocols Support
WCF
HTTP
TCP
Named pipes
MSMQ
Custom
UDP
ASMX
HTTP only
Hosting
ASMX
Can be hosted only with HttpRuntime on IIS.
WCF
A WCF component can be hosted in any kind of environment in .NET 3.0, such as a console application, Windows application, or IIS.
WCF services are known as 'services' as opposed to web services because you can host services without a web server.
Self-hosting the services gives you the flexibility to use transports other than HTTP.
WCF Backwards Compatibility
The purpose of WCF is to provide a unified programming model for distributed applications.
Backwards compatibility
WCF takes all the capabilities of the existing technology stacks while not relying upon any of them.
Applications built with these earlier technologies will continue to work unchanged on systems with WCF installed.
Existing applications are able to upgrade with WCF
New WCF transacted application will work with existing transaction application built on System.Transactions
WCF & ASMX Integration
WCF can use WS-* or HTTP bindings to communicate with ASMX pages
Limitations of ASMX:
An ASMX page doesn’t tell you how to deliver it over the transports and to use a specific type of security. This is something that WCF enhances quite significantly.
ASMX has a tight coupling with the HTTP runtime and the dependence on IIS to host it. WCF can be hosted by any Windows process that is able to host the .NET Framework 3.0.
ASMX service is instantiated on a per-call basis, while WCF gives you flexibility by providing various instancing options such as Singleton, private session, per call.
ASMX provides the way for interoperability but it does not provide or guarantee end-to-end security or reliable communication.
WCF is far wider in scope than ASP.Net webservices.
WCF can run in any application. APS.Net webservices only run in IIS.
WCF supports models like ReST, Remoting, SOAP, MSMQ etc. ASP.Net only supports SOAP
WCF is more configurable.
WCF supports a more declarative way of programming. You can get more done with less code.
ASP.NET Web Services are pretty much just that. Web Services. They're SOAP/WSDL based and provide their services only to the web.
WCF Services offer a much more flexible framework. For instance, depending on how the service is defined, it can be a Web Service hosted in IIS which serialized its data via XML and uses the REST model...or it can be a Remote Windows Service that is hosted in it's own process and serializes its data via binary. All of this is achieved using the different Service/Data contracts in WCF.
In short...you can make a WCF service look almost identical to a .NET 2.0 Web Service fairly easily but, with a little work, you can do a WHOLE LOT MORE.
I have a Windows Service which performs a certain function, and then needs to send that information off to a webservice for processing. The webservice is hosted by a remote web application. I am trying to ascertain the best way to call the webservice(s) as each web application might be only 2.0, or 3.5 etc. In my windows service, I am defining each "client" in the app.config, e.g.
<Client WebServiceUrl="http://location.com/webservice.svc" Username="" Password="">
</Client>
The web application must implement two web services that are required for my windows service to run, however not sure the best way to implement the "rules" for the web application.
EDIT:
I'll try and rephrase..
The Windows Service runs every 30 seconds and obtains a list of information. The service supports multiple "clients" as shown above. When each client process is run, the data is collected and is then needed to be sent to the supporting web application.
The windows service does not know what to do with the data, it is just sending it. Each web application for a client would be in different locations, and could possibly be built in 2.0, 3.5, PHP, etc. All the windows service cares about, is that when it performs its processing for a client, it is able to send the data to the webservice location defined in the app.config of the windows service.
What I'm trying to determine is how to connect to the webservice (which I'm leaning towards WCF, however Basic or WS not sure), and what rules need to be defined for the web application in how to build the response.
If the Windows service is to support php applications etc, WSHttpBinding would not be an option, which would mean BasicHttpBinding would then work. The other thing to decide is whether or not to utilise a RESTful service or SOAP service.
Hope this makes more sense.
I'm not really clear on what you are doing.
It seems like you have 3 things: A Windows Service, and then a web service, hosted in a web app.
I think your question is, what to use, REST, ASMX, WSE or WCF, when interconnecting the Windows Service app with the remote web service.
ASMX, WSE and WCF are alternative programming models for the web service. REST is not a programming model. It is not like the other three.
ASMX and WSE will require that you use Web services and SOAP.
WCF can allow you to use Web services and SOAP, REST (XML or JSON) over HTTP, or a binary format over TCP, among other options.
Because it is flexible and current technology, I'd recommend WCF. ASMX is now termed "legacy technology" by Microsoft. Doesn't mean it won't work, but it will not get updates. (Much like WinForms versus WPF). WSE is no longer in mainstream support, as far as I know. For these reasons, I wouldn't recommend starting a new project on WSE, nor on ASMX.
WCF is more general than ASMX and can seem more complicated, for that reason. But once you make some choices and zero in on what you want (for example choose HTTP and REST, or choose binary and TCP), it's more powerful. WCF can be used as the programming model on both the client or sender (in your case, the Windows Service, I guess) and/or on the server (the web service hosted in the web app).
Using WCF on the client side does not imply you must use it on the server side, and vice versa. On the other hand, if you control the source code on both ends, I would recommend using WCF on both sides.
As for "how to implement the rules for the web app" - I don't understand what you are asking there. Maybe if you are more specific on the question there, someone will be able to help out.
Update: Based on your additional explanation, I'm going to suggest you look at the REST stuff in WCF for .NET 3.5. In PHP it's very easy to implement a REST-style service, and with WCF, the same is true for .NET. Now in your case the Windows service is the client and it is sending out a request, an update request, to various servers that reside on your customers' networks. According to REST principles, I'd make those outbound requests PUTs or POSTs, depending on the semantics of the call.
Then you could ship some example service code to your (uppercase) Clients, to get them started on building what they need to receive your outbound PUT/POST messages.
Security is a concern though. You didn't mention it at all, which is surprising. Security is not one of those things best deferred, so that you "add it on later". You should think about it early - it may affect the protocol choices you make. For example, if you need to mutually authenticate the clients and servers (the latter at your "uppercase" Clients' networks), then you may want to go with SOAP, which gives you good options on the protocol side for security. Secure Web services extensions (WS-Sec, etc) are well supported in WCF, but not sure about the status of this capability in PHP.