Overview

The following picture gives an overview of the DSJOS architecture. It shows a variety of interconnected architectures, like workstations, clusters, and supercomputers, all taking part in a single DSJOS federation, identified by a federation authority. It also shows multiple clients using DSJOS to run some applications.

The federation authority acts as a single point of contact for the DSJOS federation. It runs the 'dsjosr' process, which acts as a central repository for federation data, like policies in use by the federation. In addition, it serves as a load dividing frontend to the DSJOS architecture.

Every participant in the federation runs the 'dsjosd' process. Together, all these daemon processes establish a view of a single Java Operating system. Within each daemon, resources instantiated by client submitted applications are shown. Exactly one process object is created for each submitted application. Its threads and Java objects are scattered over the nodes of the federation. Java classes are shared by the Java processes, and each class is instantiated only once. Processes, classes, threads, and objects instantiated on one node can be accessed from any other node, thus obtaining the single Java OS view.

The client typically runs a client application, through which they can submit jobs to the DSJOS federation. As far as the client is concerned, the federation authority is the federation.