Is there an issue in unix running one C++ binary multiple times and parallel?

Question

I have a compiled binary of a server written in C++ on my unix system. I want to dynamically start servers using a small script. I can specify the port the server will be running on as an argument. My question is if there is a problem with starting one binary multiple times and let them run parrallel instead of copying the binary. In my test it worked as expected but I want to be sure that there are no problems.

Answer 1

First you can run multiple instances of the same binary on almost all operating systems, you do not need to copy it. However there is a deeper issue.

It all depends on how the application is written. In a perfect world no, you would not have any issue, but the world isn't perfect. An application might use a system wide resource and assume it has exclusive use of that resource. This is not unheard of for larger applications such as servers. You already mentioned one thing, the port, but as you said you can change that but are you sure that is the only thing? If you are sure than you can run multiple instances without an issue. However there are other resources the application might assume it has exclusive use over, files could be one, that if you run multiple copies this assumption is broken. The application would then most likely not behave as expected.

Answer 2

Most operating systems allow you to run as many instances of the same program as you wish. It is program's responsibility to enforce any limit on the number of instances, if any.