I'm beginning a project right now that will require a pretty extensive web back end. Of the different calling conventions, we have found that the easier and more cost effective approach is to build a standard SOAP web service.
So now, we are in the process of looking at the different web service frameworks in order to determine which will meet the business needs:
Security
Cost
Time
I've only worked with WCF, which I was fairly content with, but I would like to explore all other options before I make a definite decision. In your experience, what do you feel is the best web service framework?
Web Services Interoperability Technology (Java)?
WCF (.NET)?
ActionWebService (Ruby)?
On a side note, we need a framework that can securely be accessed via iPhones, Windows Mobile Devices, and Blackberries.
Thanks in advance for your help.
Chris
WCF can be used to make both SOAP and RESTful Web Services. Interoperability is guaranteed as long as you stick to standards. But the more standards you put on it, less platform can catch up. In that sense REST on Basic Auth over https would be very light weight. Also see WS-I Basic Profile. Java vs .NET would be matter of taste, I think. WCF is not perfect, but it mostly seems to do the job.
One thing to consider about WCF is that it has a very rich extensibility model. Anything it doesn't do out of the box, you can teach it to do, with little or no change to your basic service.
Related
Given current maturity of REST frameworks/APIs, which should be the better option for a new SOA project - soap or rest?
PS - Excuse me for a being a noob, let me know if asking a wrong question!
This is a bit up in the air. Now I am generally a bit biased towards REST, but REST and SOAP are two different animals. REST is more of an architecture style where as SOAP is a delineated protocol. Having said that, I have definitely written many SOAP interfaces.
One thing that I would like to note is that with REST you are not limited on the representation of the data, so it could be in XML, JSON, YAML, etc. As a result your data can be much more lightweight. However, for SOAP you must use XML. One thing to definitely take into account though is how this service is going to be consumed.
Generally, if your service is going to be used by a Mobile Device(Android,iOS, Windows Phone) there are a lot more frameworks around REST, so it would be wise to utilize those existing frameworks. If you have older large corporations connecting to this they are likely going to have existing SOAP implementations so they are going to be more comfortable with accessing SOAP services.
I would say however that providing both is not really that far of a stretch. If you have a service at /api/v1/customers << this could be your rest URL and for the SOAP protocol use /api/v1/soap/customers/*. As long as your business logic, if there is any is encapsulated into different functions, then both the SOAP and REST implementations can call it.
I hope that this is helpful, but with many questions around technology, don't try to force your use case fit the technology. Your technology choice should flow from the use case.
SOAP is a xml based protocol and REST is an architectural style for ROA (Resource Oriented Architecture), not a spec or a standard.
Web services vs. SOA and pretty URL vs. REST
Having web services does not mean you have an SOA architecture
This is perhaps one of the biggest misconceptions about SOA architecture I hear very very often. I see many developers thinking that if they have a web service or two in their architecture, they say their architecture is an SOA architecture. I think this comes because of two reasons: 1) “Web service” and “service oriented” resemblance in naming makes people think they are the same thing; 2) As web services are the most common way of implementing an SOA architecture, this pushes people think that when they have created one web service, their architecture is an SOA architecture.
An SOA architecture is characterized of composition of independent services which encapsulate business functionality and expose it as a service, which can be a web service, a windows service, or any other form of exposure. Ubiquity of web and advancement of web development technologies which made the creation of web services easier have put web services as a mean of choice for implementation of an SOA architecture, however, the definition of a service within an SOA architecture does not put web services in any special position regarding implementation of SOA architectures.
Having pretty URLs does not mean you have a REST architectural style
REST architectural style is another popular topic lately, and as such, is subject to a lot of misconceptions as well. REST has brought simplicity to implementation of web services and is embraced very popularly from the web development community. It plays well with the HTTP protocol, which we are familiar with ever since the beginning of www era.
One characteristic of REST architectural style is that resources are at the center of the architecture, and they are beautifully represented in URLs. REST has brought us pretty URLs, and therefore people have created a connection between the URLs and REST architecture. Leonard Richardson has developed a maturity model which tells the level of your API or RESTful services to what degree are RESTful.
source
I was wondering if someone has successfully implemented a RESTful Shopping Cart Web service. I am perticularly interested in Production level implementation rather than test app.
Would there be any advantage in this approch rather than SOAP-style?
Personally, I haven't. I would be completely astonished if somewhere in the world "someone" has not. I know of plenty of equivalently important RESTful services running in production or production ready. As an example one of my employer, IBM's, flagship products WebSphere Process Server, exposes restful services.
I'm guessing that you are asking the question from the perspective that suspects that RESTful services are not yet mature. My experience is that because of their relative simplicity the support stack for such services reached maturity quite quickly. In the Java world JAX/RS is very easy to use and seems to me to be very stable.
Advantages: Simplicity, really easy to consume from JavaScript, especially with JSON payloads, potential for much simpler life-cycles and versioning than with WSDL.
Disadvantages: the more advanced WS-* capabilties are not available as standard.
I know, WCF Service is better then ASP.NET Web Service due to (a lot of reasons). But is it reasonable to use WCF service if everything you need is to have 3 simple methods, each of them with 2-3 parameters?
For me it seems like firing on birds with cannon.
Thanks a lot!
That a framework has features you don't need isn't a great reason not to use it. WCF will work great for a simple service of just a couple methods, and you'll have the flexibility of protocol bindings, extensibility, security, etc. there if you ever need it. That said, the 3.0 version of WCF did require a lot of intellectual overhead to get started; the team is working to reduce this and make it as easy as asmx to get started. If you can, use 4.0.
There are quite a few opinions out there on this. The most common theme that I come across is to your point, simple job/simple service. That being said I think it is pretty quick and easy to throw together a WCF service and have been converting any of our legacy ASMX services to WCF as they need updating, even the smaller ones.
I'm designing a set of web services to allow our clients to connect from their apps to one of our systems. Our clients have their apps developed in all varieties of frameworks (.NET, Java, PHP, Python and even the occasional all JS app), so obviously WS is the way to go.
Investigating a little about truly interop WS I've found that the way to go is to design first the WSDL and XSD and derive the implementations from there.
What i'm really looking for is guidance if this is really the way to go. I've read that WCF creates interoperable WS but i'm not a fan of MS creating something standard.
Should i use WCF or there is a good set of tools for designing WSDL and XSD without the pain i'm expecting.
Thanks in advance
If you want to interoperate with JavaScript, then best to make more of a REST style API. This is basically just standard HTTP calls, so you're interopable from the get-go. However, you've kindof indicated that you want to use SOAP, so ...
If you're going with SOAP/WSDL, I'd definitely advocate using the server platform - yes, even .NET - to generate the WSDL, then simply check that the options you're using are producing a good, interopable WSDL.
I'm a Java developer with a history of PHP & Perl, and I've interoperated with .Net on a number of WS projects, from both sides of the coin (as server and client). There's usually no major problems - just be wary of a couple of things:
certain proprietary elements that MS
mixes in with the open standards. For
example, they may offer NTLM-style
authentication, which really isn't
needed in most use cases,
particularly when you're using SSL
certificates.
SOAP has taken a few
different forms over the years
(Document/Literal, RPC/Encoded, ...)
you'll probably find you don't need
to worry about this, as RPC/Encoded
died along with old frameworks, and
most modern frameworks tend towards
Document/Literal
SOAP offers a few
bolt-on standards (e.g. MTOM & DIME
for attachments, and SOAP-WS for
authentication). Try to avoid those
bolt-ons, as different platforms
implement different subsets.
For security, I'd advise to use SSL for
the trust & confidentiality, and then
either HTTP basic auth, or simply custom
string tokens in your soap request definition.
Just keep the WSDL as minimal as possible, try interoperating quite early in the process, and you shouldn't have too many problems
You can use WCF and contract-first development.
If interoperability is the main concern then I would recommend using WCF to provide the service implementation but instead of relying on WCF to generate the service interface to use contract-first development to model the interface.
A really good article on how to develop this way is Schema-based Development with Windows Communication Foundation.
If you are going to roll your own WSDL and schemas you are probably going to want to get an editor like XmlSpy or LiquidXml. I like the price of LiquidXML (free!) but I can't recall if you have to pay for the web service features.
Another interesting tool for contract-first development with Visual Studio and WCF is WSCF.blue. I haven't used it but it does appear to be actively developed based on the WCSF.blue roadmap.
WSDL and XSD are language independent, you just have to have some mechanism to communicate using other languages. Good thing for you to do would be IMHO core data design, so you would not need so many XSD for the same data entities.
I'm not sure what you mean when you ask "should I use WCF"? WCF is the current mechanism for developing web services (and other kinds of communicating services) on .NET. There is no other current mechanism. The others are obsolete, or else considered "legacy technology".
My gut feel is that document based web services are preferred in practice - is this other peoples experience? Are they easier to support? (I noted that SharePoint uses Any for the "document type" in its WSDL interface, I guess that makes it Document based).
Also - are people offering both WSDL and Rest type services now for the same functionality? WSDL is popular for code generation, but for front ends like PHP and Rails they seem to prefer rest.
Document versus RPC is only a question if you are using SOAP Web Services which require a service description (WSDL). RESTful web services do not not use WSDL because the service can't be described by it, and the feeling is that REST is simpler and easier to understand. Some people have proposed WADL as a way to describe REST services.
Languages like Python, Ruby and PHP make it easier to work with REST. the WSDL is used to generate C# code (a web service proxy) that can be easily called from a static language. This happens when you add a Service Reference or Web Reference in Visual Studio.
Whether you provide SOAP or REST services depends on your user population. Whether the services are to be used over the internet or just inside your organization affects your choice. SOAP may have some features (WS-* standards) that work well for B2B or internal use, but suck for an internet service.
Document/literal versus RPC for SOAP services are described on this IBM DevelopWorks article. Document/literal is generally considered the best to use in terms of interoperability (Java to .NET etc). As to whether it is easier to support, that depends on your circumstances. My personal view is that people tend to make this stuff more complicated than it needs to be, and REST's simpler approach is superior.
As mentioned it is better to choose the Document Literal over RPC encoded whenever possible.
It is true that the old java libraries (Axis1, Glue and other prehistoric stuff) support only RPC encoded, however in today's most modern Java SOAP libs just does not support it (e.x. AXIS2, XFire, CXF).
Therefore try to expose RPC encoded service only if you know that you need to deal with a consumer that can not do better. But then again maybe just XML RPC could help for these legacy implementations.
BiranLy's answer is excellent. I would just like to add that document-vs-RPC can come down to implementation issues as well. We have found Microsoft to be Document-preferring, while our Java-based libraries were RPC-based. Whatever you choose, make sure you know what other potential clients will assume as well.