iceManager. The DeviceManager is the hard- a CR system, to create a specific waveform. The wave- ware booter; its job is to install all the appropriate form's individual components and their relative connec- hardware for a particular box and to maintain the file tions are described in an eXtensible Markup Language structure for that particular set of hardware. The boot-up (XML) file, and the component's specific implementa- sequence for the DeviceManager is fairly simple, as tion details are described in another XML file. The dif- shown in Figure 2.4a-8. ferent XML files that are used to describe a waveform in As seen in Figure 2.4a-8, when an instance of the the SCA are described in the section Profiles. DeviceManager is created, it installs all the Devices de- Figure 2.4a-9 shows an outline of the behavior of the scribed in the DeviceManager's appropriate profile and ApplicationFactory. As seen in Figure 2.4a-9, the Appli- installs whatever file system is appropriate. After in- cationFactory receives the request from an external stalling the hardware and file system, it finds the central source. Upon receiving this request, it creates an instance controller, in this case the DomainManager, and installs of the Application class (discussed next), essentially all the devices and file system(s) a handle for the waveform. After the creation of the In a distributed system with multiple racks of equip- Application object, the ApplicationFactory allocates the ment, the DeviceManager can be considered to be the hardware capacities necessary in all the relevant hard- system booter for each separate rack, or each separate ware, checks to see if the needed Resources already exist board. As a rule, a different DeviceManager is used for and creates them (through an entity such as the each machine that has a different Internet Protocol (IP) ResourceFactory) when they do not already exist, Request Profile Create Allocate Application Needed Device DomainManager Object Capacities Request Inform Instantiate Needed Connect DomainM