Cooperative Management of Embedded Resources in a Distributed Environment

We define an embedded resource as a resource that physically attaches to exactly one machine. Examples include modems, printers, real time monitoring devices, and computers used for software development. Conventional distributed systems do not provide general purpose mechanisms for accessing remote embedded resources. At Purdue, we have several backClId computers that we use to develop, test, and evaluate new operating system designs and networking protocols. We connect the console terminal port of each backend machine to a frontend machine executing the UNIX operating system. We use the rrontend machine and other hosts in the system to edit/compile operating systems for the backend machines. We download the executable image onto the backend machine, run it, and evaluate its performance. To enhance our development environment, we designed a system that allows users on any host in the distributed environment to transparently access any backend machine. In addition, the system regulates access to each backend machine, only allowing one user per backend at any given time. We generalized the system to support a wide variety of embedded resources distributed across heterogeneous machines. This paper describes our simple, general purpose system for locating, managing, and accessing embedded resources in a distributed environment. The Distributed Resource Management System allows users to access embedded resources transparently without knowing the resource's location or the characteristics of the machine to which the resource connects. The system also supports a mutual exclusion reservation system that allows users to cooperatively share embedded resources. ·Tllis work was supported in part by a grant from Sun Microsystems