Threading in RPC::Lite
RPC::Lite supports threading if you have the Thread::Pool module installed. Threading can allow for more robust services but you must be aware of all the pitfalls threaded programming entails. Don't enable threading unless you need it and are aware of the issues you must take into consideration.
The intention of providing threading is to allow for servers that can handle both long and short-running requests. For example, you might implement a simple Authenticate() method which matches a given username/password with an entry in a database. That call should be relatively trivial and return quickly. However, you might also implement a Search() method which can take seconds or longer to return. In a non-threaded implementation, any call to Authenticate will block if a Search call is in progress. Obviously, that's not optimal behavior. With careful programming and threading support, long-running calls need not make the server unresponsive to other incoming requests.
All of the caveats that come with multi-threaded programming will apply to a threaded service, however. It's important to keep in mind that you may need locks around certain functionality to avoid the standard data corruption issues with concurrency.
RPC::Lite::Server has more information on how to enable and configure threading.