We have a legacy "Web application" that uses traditional J2EE MVC architecture. The web application is like a thin proxy that does request validation and transformation, calls back-end services, and finally transform the response payload before returning it to the caller. We are planning to move this application to the APIGEE. Since most of my web app code is written in Java, I am planning to use Java callout to perform everything that is being done in my existing "Web App". What I wanted to know is - Are there any other way to migrate the "Web App" logic in the APIGEE proxies? Any experiences you can share?
Depending on the complexity of the transformations necessary, you can refactor to use Apigee native mediation policies and JS, maintaining the JS code directly inside a JS policy in the proxy package. Else call-out to proper Java. It might be lower effort in the short-term to just hang onto your Java and call-out to it, but you may find better performance in the long term if you refactor.
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I'm brand new to C#/.NET
Why does ASP.NET have so many different choices of projcets? (Web Application, Web API, Web Site, MVC ect). I just want to listen on a tcp port, and a way to send a response. If there are libraries to help me do routine stuff like constructing the HTTP request, parsing the header, ect - then cool. But I don't want a super opinionated framework that tries to do everything under the sun.
Why do I need IIS at all?
Addressing your points in reverse order, first - why do I need IIS?
The answer is, maybe you don't. If you are doing a simple listener that won't be exposed to the public internet, then you don't need it.
If you are doing a web application that needs to scale, be robust and easy to manage then it can help you with:
Logging
Operating in a multi-server environment for scale/high availability
Handling multiple requests in an isolated way
Serving multiple applications from the same host with sandboxing to ensure each application has guaranteed resources (memory, CPU)
Application lifecycle management
IP address restrictions
support for FTP, CGI, WebDAV
URL rewriting
Response header manipulation
Failed request tracing
Protection against some DoS exploits like slow HTTP attacks
Etc.
In short, it is an industrial strength, real world web server that will keep your application up reliably in a hostile world and scale as your application grows. it is certainly overkill for some cases if you don't need this kind of scale/high availability/management capability. In those cases you have the option to self host ASP.Net in a Windows Service or even a console app. This might sound complicated, but it has been made pretty simple by OWIN - Open Web Interface for .Net. This is an abstraction of the interface used by Asp.Net to communicate with its hosting server.
There is a very good tutorial on how to self host web API in a console app here
http://www.asp.net/web-api/overview/hosting-aspnet-web-api/use-owin-to-self-host-web-api
It does exactly what you ask for in your comment:
You create a console app project
You add references to the right assemblies (the tutorial uses NuGet to download the assembly packages)
You code up your web operation logic
You compile
You run the resulting exe
That's it!
On your second point about ASP.Net - it is a framework that has gone through a lot of evolution trying to keep up with very rapid changes in the web development world. This meant it got a bit bloated and lost some of its coherence, but recently the developers have been focussed on making it more lightweight, more modular and simpler. Scott Guthrie summarises it in his blog:
http://weblogs.asp.net/scottgu/introducing-asp-net-5
Why does ASP.NET have so many different choices of projcets? (Web Application, Web API, Web Site, MVC ect). I just want to listen on a tcp port, and a way to send a response. etc...
Because each project has its own purpose.
If you want to just listen on a TCP port then you could go learn Microsoft's Katana OWIN (but I highly doubt if this is what you want).
Katana OWIN
Briefly going through each projects purpose:
"Web Application" actually opens up another window and lets you choose from the following:
Web API is for exposing RESTful services or JSON data.
Web Forms is for making web pages that use Web Form components.
(A bit like Windows Forms, but Web)
MVC is for making Model-View-Controller web applications. This is where you build components with a separation of concerns. Model for data. View for what the user sees. Controller for controlling how your page behaves.
Why do I need IIS at all?
IIS is for serving .NET applications.
Without it, it would be quite hard to serve .NET applications.
I'll start with 2 then move on to your first question. IIS will run whatever the .NET web service you need, be it a monstrous WCF service, an ASP.NET application or the most basic http handler.
To my knowledge, ISS is the most straightforward way to use .NET web services. If you are used to PHP, it's basically LAMP or WAMP for .NET, which means it is sort of necessary. There are alternatives, as Mike Goodwin points out, but I have to admit I am not familiar with those third parties. Since replacing a layer for another doesnt mean much, I would stick to the "normal" procedure.
Since you dont want the framework to do a truckload of operations for you, your best bet might be along those lines:
Create a basic ASP.NET projet
Remove the default ASP.Net page because it seems you dont want it
Add a Generic Handler to your project. This will result in a myFile.ashx, which handles http requests and let you build any response you want
Of course, if you dont want to bother with IIS configurations, you'll need someone to setup an URL on IIS and map it against your handler repository.
EDIT:
"Abstraction layers" would be the very definition of frameworks, for good or ill, so you're stucked with it.
Now, since you have a low level background a not-so-intrusive way to work with the .NET web services would probably be the three steps I suggested earlier. You are still stucked with IIS though, in order handles the communications (i.e. manages sockets/requests). That's the way the framework works.
STILL, THERE IS HOPE. If you have complete control over your server (which is not my case, some other IT team manages the web servers), you certainly could build a windows service that listens to some socket and work the requests accordingly. It is a most unusal solution if you want to serve web pages, but would work rather well if you only want to push some data through http requests. If you go down this path, I suggest you take a look at the System.Net namespaces, you'll find some classes like "Socket" there. Combined with a console application or a windows service, you could work something out.
One of my coworkers is former microcontroller designer, I know exactly what kind of feeling you have towards the .NET framework. You'll go through some frustrations at times, but most of the time there are work arrounds. Feel free to request more details if you need some.
I can't find anything on the implementation of service discovery for the ASP.NET Web API. For a new project I need to make a decision between WCF and Web API. The service element will be consumed by a variety of clients, mobile, client-side JavaScript but also an ASP.NET website.
For the website the convenience of being able to generate a client against a WCF service is obviously a plus. I am not that familiar with RESTful web services but I see that there is Web Application Description Language (WADL). Maybe it is my ignorance but surely it is a good thing to be able to advertise the correct way to consume your service?
My main question: is there anything that generates a WADL or similar for WEB API?
Secondary question: this tool looks like it generates a client based on a WADL, is there anything else that makes life easy keeping a client up to date with a RESTful web service?
There is a considerable amount of work going in there. It is not finished but watch the space.
Having a look here (and newer Yao posts):
http://blogs.msdn.com/b/yaohuang1/archive/2012/05/21/asp-net-web-api-generating-a-web-api-help-page-using-apiexplorer.aspx
Also
http://blogs.msdn.com/b/yaohuang1/archive/2012/06/15/using-apiexplorer-to-export-api-information-to-postman-a-chrome-extension-for-testing-web-apis.aspx
I blogged an approach to generating WADL with ASP.NET Web API here: http://blogs.msdn.com/b/stuartleeks/archive/2014/05/20/teaching-asp-net-web-api-to-wadl.aspx
I have an application that I'm building and for the moment, I built some web services using ASMX. In the end, the application will be deployed on azure. The web services are really simple in that all they do is call a class in the AppCode folder that handles all the work.
Is it going to be better/easier/faster/more performant to move my web services to WCF or to Web API?
Thanks for your suggestions.
PS: I want to add that the web services will need to work in HTTPS. At the moment, they're on HTTP because I'm in development mode.
One-liner: if you have already got a working code and it is risky to move it to another technology stay with the working code.
Depends who is answering.
Web API embraces HTTP and gives you flexibilities not possible with ASMX and WCF. If you care about HTTP, content-negotiation, media types and you need your service to be called from any client (including AJAX) then Web API.
If you need to be able to use WS* security standards (e.g. using X509 certificates, ADFS, etc), possibly change your binding, serve to different clients using different bindings, extensibility, etc use WCF.
If you already have a working code, and all you care about is RPC and your clients are always going to use ASMX then stick with ASMX.
Performance
No benchmark but my gut feeling, in descending order: Web API, ASMX, WCF
Easier
In descending order: ASMX (since you know it), Web API, WCF
Faster development
If you know them all, Web API and ASMX then WCF
PS: it is good to pick up new technologies. The way things are going (and since you are already moving to Azure) it is important to invest on new technologies.
We have an ASP.Net C# application that requires some form of a web services implementation for integration with other applications. Currently we have been looking at servicestack and also using an ESB e.g. Mule.
I am trying to figure out the best way to integrate an ESB like Mule into our ASP.Net application.
Do we need to build a web service into our ASP.Net application so that an ESB can integrate with it?
If yes what would be a good approach for selecting a web service type (e.g. REST, WCF, SOAP, Servicestack) that will be compatible with an ASP.Net application and Mule?
Do we need to build a web service into our ASP.Net application so that
an ESB can integrate with it?
Usually it's the other way around. An integration middleware, like Mule, speaks tons of protocols just for the sake of being able to connect to existing systems without changing them.
If yes what would be a good approach for selecting a web service type
(e.g. REST, WCF, SOAP, Servicestack) that will be compatible with an
ASP.Net application and Mule?
If your application has really no pre-existing channel you could use to integrate with (not even a simple web form HTTP POST? really?) and you want to expose an API so an integration middleware can connect to it, pick the architecture/technology that maps to the API style you're creating (REST for a resource oriented API, SOAP for a RPC oriented API).
This sounds backwards. What are you required to integrate with, and what capabilities are you trying to provide?
A web service is decoupled from its implementation, you would choose to use a web service if you're trying to expose your system capabilities in an interoperable way so that it's accessible by a broad range of clients.
What you do within a web service is up to you, i.e. you could then for example connect with your ESB. Nothing is precludes you from doing that. ServiceStack also supports hosting from within an existing ASP.NET (or MVC application) see the Hello World example for different ways of configuring ServiceStack.
REST / RPC has to do with the design of your web services and ServiceStack supports both models. i.e. inherit from RestServiceBase if you want to provide different implementations when the service is invoked with different HTTP Verbs. Inherit ServiceBase if you want the same implementation to be used no matter how it was invoked. This article shows the difference between REST vs RPC/SOAP - and how you can support both in ServiceStack.
So if your exposing a single operation (or want to support SOAP) use ServiceBase, if your exposing a 'Resource' where you want to allow it to be managed using different HTTP Verbs use RestServiceBase.
Is there a business case for using WCF WITHIN your web application (ASP.NET/SQL Server)?
I'm not talking about a service to be consumed by others, but rather a service to be consumed WITHIN the web app. So far, the only use for web services WITHIN the web app I came up with is when I need to call the database from the client (through AJAX).
Please don't give me the copy/paste lesson on web services, all I'm looking for is a CONCRETE EXAMPLE of WCF benefiting the web application, and NOT the other apps consuming the services.
Quick clarification: by "web application" I mean a self-contained CRM of sorts. It does a lot, but it DOES NOT talk to any external apps/db's, and DOES NOT need to have service points open for other apps to consume.
We have a Windows service that gathers live data from the web. Because the data is ephemeral (it's only really valid for around 3 minutes), there's no point in recording it in a database. To retrieve data, the Windows service offers a (TCP transport) WCF interface which is only exposed to the web-server, from which our web-app requests data.
I think it very much depends on how you define "application".
If you're talking about a single web application then with the exception of provision ajax data as you've already noted I'm struggling to think of a generic reason why you'd want to as a web service (even more so for WCF) is just an exposed API and if you're in the application surely it would be better (in all kinds of senses) to go straight to the API without the additional overhead of wrapping and unwrapping the calls and the data - which is pretty much redundant.
On the other hand if by "application" you mean an assembly of "stuff" that delivers a solution to a set (or even various sets) of end users then yes, of course... there is definitely a case where the flexbility of having components communicate via services outweights the overhead issue. Where it gets grey is if there is an assumption that a single application will (or at least might) later become multiple applications wired together - but if you're not doing it now then you're just causing yourself pain you don't need so shouldn't bother. If you need to split it deal with that as a self contained exercise as and when you need to split it.
One concrete example from my practice: On one web site we use actively tables which are implemented with respect of jqGrid plugin to jQuery. The contain of grids will be loaded per ajax. So the most pages of the web site are very simple and have clear XHTML code. The business logic with the interface to the database is inside of WCF service. Inside of WCF service we get data also from other information stores of the organization. In the same way if one will need later to have an input from our project the WCF service will be perfect.
So the usage of WCF WITHIN in our web application helps to archive clear interface, clear separation business logic from the HTML markup and better testability (with utit tests integrated in Visual Studio).