48 Existing Parallel and Distributed Systems, Challenges, and Solut ions
potential queuing systems and potentially complex APIs exposed by those
software systems.
Rationale: For many modern applications, integration of various dis-
tributed systems is desirable. For instance:
1. business applications using services from various companies, entities in-
cluding government and local authorities,
2. scientific computing for gathering data from, e.g., distant radio tele-
scopes from all over the world and processing in parallel on various
clusters,
3. ubiquitous computing when local services are discovered and used dy-
namically in a workflow application based on the physical location of
the device.
As an example, the scientific workflow shown in Figure 2.14