Multi-Tier Master-Worker Architecture

The PROOF system implements a multi-tier architecture as shown in the figure:

The client is the user that wants to use the resources to perform a task. The master is the entry point to the computing facility: it parses the client requests, it distributes the work to the workers, it collects and merges the results. The master tier can be multi-layered. This allows, for example, to federate geographically separated clusters by optimizing the access to auxilliary resources, like mass storages. It also allows to distribute the distribution and merging work, which may become the bottle-neck in the case of many workers.

PROOF-Lite, the version of PROOF dedicated to multicore desktops, implements a two-tier architecture where the master is merged into the client, the latter being in direct control of the workers: