Is it likely appdomains will help in this scenario?

Question

I have a dotnet process that through calls to an unmanaged dll is communicating with a Java process.

Under some circumstances, the Java process appears to be crashing and taking my dotnet process down with it. No exceptions are raised, the process just dies. Upon crashing, java is creating a log file with names like "hs_err_pid3228" etc.

Not having received any satisfaction from the vendor that is providing the unmanaged dll and the java process, I am reduced to trying to mitigate the problem which would necessitate ensuring the calls into the java process, if they crash, don't take down my process.

Having read various articles, appdomains seem a likely candidate to use - my theory being I can with a bit of work separate my functionality that calls the java process and run it in a separate appdomain, which will hopefully allow me to if not catch the appdomain going down, at least detect that it has happened and restart that functionality.

Has anyone had a similar sort of issue? Does this approach seem reasonable to those of you with more experience of appdomain?

To make it even more fun, the Java crash is not really reproducible - it seems very random and I'm still battling with how I'm going to TEST that separating into the appdomain

Answer 1

This is a reasonable use of AppDomains, and what you propose will work.

In a similar vein, I once used AppDomains to create a single application that watched for itself crashing for exception reporting purposes. The application started itself up, created a new AppDomain, then re-executed itself in the new AppDomain, which then detected it was running in an AppDomain and executed normally. When an exception happened in that AppDomain, the original process is notified, it tears down the child domain reports to the user that an error occured, asks whether they want to report it or not, then picked itself up and tried it all over again.

EDIT: To give you a headstart, if you want to look at the Program.cs for that project, I've uploaded a stripped down version here. (It's pretty long, so I didn't think I should post it here.)

Answer 2

Yep, leveraging AppDomains make a lot of sense here.

I've recently reworked my Windows service to load its various WCF services as plug-ins that operate within their own AppDomain. I've got a few cases in the bootstrapping process where I'm using MarshalByRefObject objects to get things up and running, but once the plug-ins are loaded, communication between the AppDomains is extremely easy using WCF.