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.
Related
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.
I need a way to exchange data between a process and a windows service.
The process (Windows Form Application, Console Application, in the future also a Web Solution) needs to instruct and interact with the windows service.
I want to know which way is the best to accompplish this.
I'll write the solution in C#, .NET Framework version does not matter.
In the past I've used Remoting (Activator), WCF Interface with Contracts, Inter Process Exchange IPC and some named pipe implementation. What is your experience? Other ways?
I would choose WCF. It is most modern and probably best supported approach at the moment. It "replaced" older technologies in most scenarios. Nice feature of the WCF is that if you need to move your service to other protocol you can do that simply in configuration.
If you expect that windows service will always run on the same machine as other application you can use WCF with netNamedBinding. If you decide to move your service to other machine you will have to change configuration (probably to netTcpBinding) because Named pipes in WCF are limited only to IPC.
My previous experiences have always been over an IPCChannel, mainly because the only code I've had to be involved in that does any form of inter-process communication. It's never caused me any problems and the code is working away quite merrily as I type.
The only real answer to this question is, whichever you're most comfortable with.
I'm just starting with distributed application development. I need to create (all by myself) an enterprise application for document management. That application will run on an intranet (within the firewall, no internet access is required now, BUT is probably that will be later).
The application needs to manage images that will be stored within MySQL Server (as blobs) and those images will be then recovered by the app and eventually one or more of them will be converted to PDF.
Performance is the most important non-functional requirement.
I have a couple of doubts.
What do you suggest to use, .NET Remoting or WCF over TCP-IP (I think second one is the best for the moment I need to expose the business logic over internet, changing the protocol).
Where do you suggest to make the transformation of the images to pdf files, I'm using iText. (I have thought to have the business logic stored within the IIS and exposed via WCF, and that business logic to be responsible of getting the images and transforming them to PDF, that because the IIS and the MySQL Server are the same physical machine). I ask about where to do the transformation because the app must be accessible from multiple devices, and for example, for mobile devices, the pdf maybe is not necessary.
Thank you very much in advance.
WCF, only consider remoting if WCF presents some issue such as performance in your use case. You have many many more scaling and customisation options available under WCF.
Depends. If sending the images over the net presents an issue then it may have to be done locally. However as in (1) your existing suggestion seems ok.
See .Net Remoting vs. WCF for a similar question.
Definitely remoting if this is an option
Transformation - same box that the service is; since the service is going to funnel the images anyway - this is the best place. I would not put it on DB server, to better distribute the load and to separate non-db load from db specific load.
In addition, look into .Net 4.0 RIA services. They allow you best combo of .Net Remoting and 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.
I am working on a project that involves an embedded system which runs a non-microsoft OS with a C program for the application and am developing .NET software for its end user applications. For remote configuring with the .NET software (which can go across firewalls), I am considering using WCF. I know only a little about WCF so far but I've read that it is supposed to be interoperable with environments other than .NET. The embedded environment has an HTTP stack but no built in support for web services. Does anyone have any experience with this kind of thing or know if it would be appropriate at all? If so please provide some advice or point me in the right direction.
Thanks!
WCF is interoperable because it's accessed over HTTP. Visual Studio can help you build client libraries very quickly for WCF, but client access to WCF doesn't require anything other than HTTP calls with the proper payload. If you're looking at a remote server call and your built-in support in your embedded environment is basic HTTP, look at building your server-side as REST-formatted methods. Your debugger will thank you.
What kinds of data are you planning on transferring back and forth? For something this low level and proprietary I would recommend sticking with good old fashioned Sockets.
I will be passing configuration data back and forth...basically to enable technical support staff to remotely program the device. If I were using sockets this could be binary data, but there is a requirement that customers with firewalls shouldn't need to open any ports. Because of this I was thinking of sending XML over HTTP. So, is it better to use WCF or REST on the server side? Or WCF with REST?
I'm curious about your "customers with firewalls" requirement. Sockets with binary data or XML over HTTP can use any port (not just port 80), and I'm curious if your device will be "listening" on the network, or just making an outbound connection. If your device is listening, you will need to open a port on the firewall. Making an outbound connection ("phoning home") is much easier on the firewall.
So I think you could use sockets and binary data. However, I have faced similar issues on the last two projects, and I really wanted to implement WCF using REST on the embedded device, but no one else wanted to do it - I'm hoping someone else will be first, and publish some results!
Good Luck! (and post your results!)