we are currently on windows server 2008 R2, IIS 7.5 and we are going to open some of our data via WCF services.
To do that, we are planing to host our services on IIS but I heard that it is not a good idea for WCF services.
The problem with the WAS is that it is general purpose hosting engine. it's actually unaware that it's actually hosting a WCF service or a website (as far as I know)
I heard that we can install an extension to the WAS called the Windows Server AppFabric.
does anybody have any experience on
AppFabric?
should my app have to use so called
'Service Bus' to use AppFabric?
should I go ahead and definitely
install it?
at most basic level, how and where
can I install it? does it require
any licence?
Thanks in advance.
I don't think IIS us a bad idea - many developers use IIS to host their WCF services. IMHO you'd only use what you need, so if all you need is a hosting framework, then IIS is a very good option for WCF services. It is (almost) unaware that it's hosting a WCF service, but that in the majority of the cases isn't an issue.
Windows Server AppFabric as it's currently released provides three capabilities: a distributed caching system (so if you need to scale out your service you can use this cache to share state among the nodes); a packaging / deployment interface (in which you can package a project and deploy it a little easier in IIS); and a management / monitoring interface (where you can monitor the instances of WCF and Workflow services which are running in your machine).
Answers to your questions:
Yes, some people have experience with it :)
No, the application doesn't have to use it. You'd only use the ServiceBus if you need its functionality (relay)
Only if you need it. If you don't need caching or the monitoring capabilities, for example, then I'd say you don't need it. I've found in the past that the least number of components I have in my system, the less likely it is to break.
Go to http://msdn.microsoft.com/en-us/windowsserver/ee695849.aspx. And AFAIK you don't need any license, but you can check on the download page to see if it has more information.
There is no real common reason why not to host a service in IIS/WAS.
If you want to absolutely, totally 100% make sure that your service is continuously running some process, such as a continuous loop or polling monitor, and if any interruption no matter how brief is a major issue, then you'd want to look at alternative hosts.
Win Server AppFabric is most useful for WF Service hosting and caching. Note however that Win Server AppFabric + Win Server Service Bus 1.0 represents the first steps in convergence between the Azure platform and the Windows Server private platform.... In other words, whichever of the two ways you choose, that's what is going to be earning your bread and butter in 5 years time.
Related
i'm about to decide on technology choices for an agent based application used in the transportaion systems domain.
basically there will be a central system hosting the backend, and multiple agents located across town (installed on desktops) that communicate with devices/kiosks collecting data and then transmitting them back to the central server. the central server could also be hosted on the cloud.
following are important
securing the data and communications between the device and the agent
and the agent and central server.
agents should be easily installable with little or no configuration.
near 100% uptime and availability
Does WCF fit the bill here?
if so what binding types should i go for? netTCP or wsHttp with SSL/HTTPS?
WCF is definitely a fit choice for this kind of scenario. For your bindings, the actual question is what technology you are going to use. Do you want to make the agents run in a non .NET environment like Java, then you should chose for wsHttpBinding. This binding communicates through SOAP and is very interoperable.
If you chose to use .NET agents, you might as well use netTcpBinding because they use the same WCF frameworks. It also supports binary encoding. If you really need to make a choice, take a look at the MSDN Documentation.
For your agents you could use a simple console application that runs in the background as a Windows service. WIX can help you with that (install an application as windows service), but thats all I know. WIX can also help you with basic installing and configure everything for you but it has a high learning curve so you might need to invest time in it.
I have a vb6-mysql client-server desktop application which is distributed as a setup file.
It uses DLL all logical operations as well as database operations. The EXE and the DLL are installed in the server as well as the client machines. When I say server which only means the database resides in that machine no other difference in EXE or DLLs.
As all the database operations are done in the DLL when connected from a client machine, performance would be less. It is not possible now to change all the logic into database.
Is it possible to store the DLL in the server machine only and use the same DLL by the client machine also so that database connection will always be from the server itself?
Is converting the DLL to a windows service the possible solution for this?
How can I to convert it to a service?
And finally, if it is possible to make the DLL act as a service, what would the connection issues be?
You appear to be trying to rediscover n-tier application development.
The usual way this would be done using VB6 within a LAN would be to create an ActiveX EXE instead of a DLL so you can use DCOM. However DCOM isn't something you'd want to expose over the Internet.
For such cases it is more typical to use a commonly-open-port protocol such as HTTP or HTTPS. Almost everyone has firewall settings permitting outbound HTTP and HTTPS connections and most of the major Web servers undergo regular hardening to make them safer to expose to the Internet.
The classic way to do this with VB6 was to use IIS to host the Remote Data Service, which uses a form of Web Service "under the covers" where your program doesn't deal with the gory details. However this is a deprecated approach, and today configuring IIS and the RDS components can be a chore since they are locked down hard by default.
This leaves you with such things as the deprecated SOAP Toolkit or 3rd party tools such as those in the PocketSOAP suite... or you can roll your own.
Doing this from scratch can be a bit of work but is more flexible, allowing REST instead of SOAP which can have advantages in itself. You could use whatever Web server you choose that can work with VB6 (via CGI, etc.).
The hardest approach to justify might seem the simplest on the surface: create your own protocol over TCP and write a Windows Service. This can be the most flexible of all but it can be more work than other options and you are on your own as far as making it and keeping it secure. You'll probably also face firewall issues depending on where your clients are and what the local firewall policies are there.
When we could rely on DCOM the issues were relatively small aside from security configuration headaches. With the Internet in the picture it is an entirely different story.
This really isn't something you undertake casually. Even assuming that your database is safe exposed to the Internet is naive and should be rethought.
I've been working with WCF fairly extensively for over two years now and have almost always taken the "lazy" route and deployed everything through IIS. Some of the reading I've done lately is starting to trend to where developers are using custom hosts in windows services or as console applications. Is there major benefits to switching over to that paradigm or is my current strategy of hosting everything in IIS give me everything I need to do WCF services?
When you go the self-hosting route, you limit the scalability & reliability options of your services. If scalability isn't a concern, you still need to consider all the service monitoring functionality that you'd have to create to be sure your services are running reliably.
If I had to pick two reasons to prefer IIS hosting over self-hosting they would be the flexibility of the WAS service instantiation model for IIS 7.x and the Windows Server AppFabric features for WCF 4.
If you're using a pre-WAS version of IIS (5 or 6), Windows services may be your best (only?) good bet for hosting WCF services that communicate via named pipes or netTCP (anything other than HTTP).
In the 3rd Edition of Programming WCF Services (link), Lowy suggests using Windows Server AppFabric in some situations, and suggests self hosting in a few cases - when you need to use the service bus and IIS 7.5 is not available, for example. Pages 22 and 23 show a couple of simple charts to help determine when to use self hosting over IIS, WAS or AppFabric. I think the first chapter (maybe more) is available for free if you get a Kindle sample.
Other than these scenarios, I'm not sure why you'd ever want to chose any sort of self-hosting over WAS. I'm curious to see if anyone presents good reasons.
I'm trying to develop and deploy a WCF service using VS2008 and Vista home premium. I don't have IIS running and understand I don't need to if I manually configure the WCF app ... using netsh.exe I believe.
Can anyone give me clear guidance on how to go from the development project in VS2008 to a useable service?
Many thanks.
A WCF service needs a host to run. As IIS is out of the question you have a couple of possibilities left:
Write a Windows NT service and host it there
Write a managed application which will host your service (less robust)
As far as netsh.exe is concerned I don't see much relevance with WCF.
I’m developing a .NET/C# application software for an instrument which has a built-in PC (Core 2 CPU/2.66GZ/4GB RAM) and will have access to the Internet from behind the facility IT firewall. The software is made up of two parts: a rich client desktop app for UI and device control and a web app (silverlight) for providing remote maintenance such as device configuration and calibration via internet using browser. This device web site will be hosted using IIS locally on the instrument. My questions are:
What is the risk of running an IIS hosted web site on a device?
What does it take to make it secure so that data and operation of the instrument is immune to potential hackers.
Is it a better design to provide web services (or WCF services) as the interface for remote maintenance? In this case, I’ll create a rich client service utility program that can consume the web services over Internet for remote maintenance purpose.
Wow, thats an interesting project!
Personally I would take a different approach and have the device/instrument pull the maintenance info from a centralized server instead of hosting the service that performs it.
Do you really want to worry about the maintenance of updates & patches on that device.
but Ill try to answer like you didn't have any choice.
1) the risks are the same as any website. you have to deal with authentication, in your case I would have allowed IP ranges.. etc.
2) Nothing is immune. But just google WCF security for a start.
3) Yes that is a better approach if the services are hosted outside the "instrument"
good luck, sounds like a fun one.
See the WCF Developer Center for much information on WCF.
One feature of WCF is that it's possible to host a WCF service in almost any kind of program. In particular, you could host a secure WCF service on your device - without needing to run IIS or any other web server at all.