If I deploy a C# console app, which does the following:
- reads message (ActiveMQ)
- processes message contents
- writes result to database (SQL Server)
Would there be any issues with running this multiple times e.g. what if I created a batch file and ran 100 instances? Would there be any conflict given that each instance would be using the same shared DLLs e.g. Apache.NMS.ActiveMQ.
The other option would be to deploy the app multiple times, but I’d rather not have to manage duplicated folders. I’m also avoiding threading at the moment but that will be an option for further development in future.
Just want to clarify what happens with those DLLs, and check that there wouldn’t be a threading type conflict, e.g. one instance writing the results of another instance’s processing to the database…
No, there will be no problem with loading the same DLL files into multiple processes as you describe. You would only run into problems running multiple instances of the same application if the process needed exclusive access to a shared resource, like a file. With regard to writing to a database, as long as you design your application so that multiple clients can write data without overwriting data or causing some sort of inconsistency with the domain integrity of the data then again, no problem.
However, I would strongly suggest you look at making you application multi-threaded if it is concurrency you need, or Application Domains if it is isolation you need. Running multiple processes is much more expensive in terms of resources than either of these two options.