This shows how oneway method calls work. The client uses a oneway call to the server to start it. In the meantime, it continues by itself and does some things. After a short while, it uses regular Pyro calls again to check on the server until it is ready. Things to notice: Not only will the client continue immediately after the oneway method has been called, the server will also process the method invocation 'in the background'. Other methods may be called while the oneway call -which takes a while to complete- is still running. For more information see the Features chapter in the manual (callbacks & oneway calls). (Due to a bug in Pyro 3.4 and older, the oneway call is not processed in the background on the server, and subsequent method calls must wait. So use 3.5 or newer to see it work as it was intended)