I am developing a solution in .Net utilising the VMWare Web Service API to create new isolated virtualised development environments.
The front end will be web based. Requestors input details for the specific environment which will be persisted to SQL. So I need to write an engine of some sort to pull the data from SQL and work on the long running task of creating resource pools, switch port groups and cloning existing VM templates etc. As work progresses, events will be raised to write logs and update info back to SQL. This allows requestors to pull data back into a webpage to see how it’s progressing or if it’s completed.
The thing I am struggling with is how to engineer the engine which will exec the long running task of creating the environment. I cannot write a windows service (which I would like) as we work in a very secure environment and it’s not possible (group policy etc). I could write a web service to execute the tasks, extending the httpRuntime executionTimeout to allow the task to complete. But I’m keen to hear what you guys think may be a better solution to use (based on .Net 3.5). The solution needs to be service oriented as we may be using it on other projects within our org. What about WWF, WCF? I have not used any of the newer technologies available since .Net 2.0 as we’ve only just been approved to move up from .Net 2.0.
First of all, a Windows Service isn’t insecure. One of software development devils is discarding a solution by ignorance or because a lack of investigation, requirement analysis and taking decisions collaborately.
Anyway, if you want to do it in a SOA way, WCF is going to be your best friend.
But maybe you can mix a WCF service hosted by Internet Information Services and Message Queue Server (MSMQ).
A client calls a WCF service operation and enqueues a message to some Message Queue Server queue. Later, a Windows scheduled task executed overtime, checks if your queue has at least an incoming message, and task processes this and others until you dequeue all messages.
Doing this way, IIS WCF host will never need to increase its execution time and it’ll serve more requests, while the heavy work of executing this long tasks is performed by a Windows scheduled task, for example a console application or a PowerShell cmdlet (or just a PowerShell script, why not?).
Check this old but useful MSDN article about MSMQ: http://msdn.microsoft.com/en-us/library/ms978430.aspx