Introduction to Science Gateways and Science Gateway Frameworks - Science Gateways for Distributed Computing Infrastructures - page 7

enables access to the most important storage types, even if jobs running in other
DCIs. This service and its use in the WS-PGRADE/gUSE SG framework is
explained in Chap. 5 . Other SG frameworks typically lack this generic approach of
accessing various types of data storages. Recently, the EUDAT EU FP7 project also
started to develop a generic solution for this problem (Riedel 2013).
Beyond simple job submissions and service calls, applications solving complex
problems like scienti c simulations require the creation and execution of scienti c

work ows. To support these more advanced types of applications, SG frameworks

should provide work ow editing and execution services. Recently, more and more

SG frameworks have such work ow support. The WS-PGRADE/gUSE SG

framework was designed from the very beginning to include work ow manage-

ment. This capability of WS-PGRADE/gUSE is described in detail in Chap. 3 .
As jobs and work

ows are executed in the various DCIs, users should be able to
observe how their execution is progressing. Therefore the gateway back-end should
be able to collect execution monitoring information from the DCIs, and the front-
end component should be able to present this information to the users in a com-
prehensive way. This is such a basic requirement that it is typically supported by
every SG framework. On the other hand providing accounting information on how
many resources for what price have been used during job and work ow execution is

also an important service of science gateways but is frequently neglected and not
supported. The WS-PGRADE/gUSE SG framework provides such accounting
service for commercial clouds when it is used together with the CloudBroker
platform. This facility is explained in Chap. 6 .
User collaboration is needed both inside a user community and among several
user communities. WS-PGRADE/gUSE provides an internal application repository
for collaboration inside a user community, and access to the SHIWA Work

ow
Repository in order to help external collaboration among different user communi-
ties. These services of WS-PGRADE/gUSE are described in Chap. 9 .
Tools for scienti c visualization are typically provided by SG instances and not

by SG frameworks since scienti c visualization is application-dependent. Therefore

such tools and services are described in Chaps. 10

15 , where the SG instances
derived from the WS-PGRADE/gUSE SG framework are introduced.

-

1.4 Developers and Users of Science Gateways

People involved in the creation, operation, and usage of gateways have different
roles, and a good gateway should provide support for all the roles.
The first category is the gateway developers , who develop the gateways. Here

we have to distinguish SG framework developers and SG instance developers . The
primary goal of SG framework developers is to develop the SG framework back-
end in a portable way that enables SG instance developers to use it without mod-
i

cations. Their second goal is to develop the generic part of the front-end, and
obviously also generate and maintain up-to-date documentation. Beyond these tasks