Constructing real-time group communication middleware using the Resource Kernel

Group communication is a widely studied paradigm which is often used in building real-time and fault-tolerant distributed systems. RTCAST is a real-time group communication protocol which has been designed to work with commercial, non-real-time, off-the-shelf hardware and operating systems, such as Solaris, Linux and Windows NT. RTCAST makes probabilistic real-time guarantees based on assumptions about the performance of the underlying system. Unfortunately, the high variability of the access to system resources that these operating systems provide may limit the predictability of the real-time guarantees provided by RTCAST. By taking advantage of a service that provides resource scheduling and reservation in these operating systems, both the hardness and timing granularity of RTCAST´s real-time services can be greatly improved. This paper describes an implementation of RTCAST which makes use of the Resource Kernel to provide highly predictable, real-time communication guarantees