How to deploy a socket server in iis application scope

Question

I am implementing an ASP.NET application that needs to service conventional http requests but the responses require data that I need to acquire from providers that are executables that provide their data over sockets. My plan to implement was:

1) In Application_Start, start a new thread that starts a socket server
2) In Session_Start, launch the session-specific process that will ultimately connect to the socket server, and from there do a Monitor.Wait on a session-specific lock object which I've stored in Application.Contents by Session key
3) When the socket server sees a new connection, make the data available to the appropriate session Contents and do a Monitor.Pulse on the session-specific lock object

Is this technically feasible in IIS? Can this concept function as a stable system?

Before answering, please bear in mind I am not asking "is this the recommended approach", I am aware it is not and if I had the option to write this system from scratch I would do this differently. I'm also not able to change the fact that the programs communicate using sockets.

Answer 1

Given the constraints this approach makes sense.

Shutdown and recycling of IIS worker processes are always throny issues when it comes to keeping state in a web app. Note, that your worker process can recycle pretty much at any time for many reasons. Some of those reasons are unavoidable: Server reboot, app deployment, bug leading to a process crash. So you need to think through what happens in those cases: All sessions will be lost while the child processes still run. Suggested solution: Add the children into a Windows Job Object and configure the Job to be killed when the parent exits.

With overlapped IIS worker recycling you can have two functioning workers running at the same time. You must deal with that possibility.

Consider the possibility that the child process immediately crashes. It will never make a connection. Make sure your app doesn't hang waiting for the connection forever.