Zero-copy for CORBA - efficient communication for distributed object middleware

Abstract

Many large applications require distributed computing for the sake of better performance and software systems that facilitate the development of such applications have attracted a great deal of attention. Modeling the application as distributed objects or components promises the benefits of better abstractions and increased software reuse. Using distributed object middleware (DOM) like CORBA (common object request broker architecture) looks promising, but most often one cannot afford its notorious inefficiency. We address the bandwidth bottleneck by extending highly efficient zero-copy communication architecture from the operating system through the middleware layers all the way to the application. In contrast to previous attempts on improving efficiency in CORBA we preserve the advantages of object oriented abstraction for the software design process and propose an efficient CORBA system that can handle bulk data transfers within the object request broker (ORB). Our prototype uses a clean separation of control-and data transfers within the ORB and for the ORB-to-ORB communication and manages to get rid of all inefficient buffering for certain types while still preserving the standard Internet interORB protocol (IIOP). It achieves the full performance that is only available with a strict zero-copy implementation across all layers between the operating system and the application.