Introduction to Science Gateways and Science Gateway Frameworks - Science Gateways for Distributed Computing Infrastructures - page 6

1.3 Functionalities of Science Gateways

A science gateway can have many different functionalities. In fact, each user
community typically requires some new functionalities according to their speci c

needs compared to the original, generic functionalities of the SG framework from
which they derive their own SG instance. Therefore here we show only the typical
functionalities that are commonly used by many different SG frameworks and SG
instances. These functionalities can be grouped according to their relationship to the
users and the DCIs:

￿ DCI-oriented functionalities :

Certi cate proxy management

-

Job submission

-

Data management

-

Work ow management

-

Monitoring the usage of DCIs

-

Accounting the usage of DCIs

-

￿ User-oriented functionalities :

User certi cate management

-

Work ow editing

-

Job and work ow execution progress visualization

-

Scienti c visualization where requested

-

- User collaboration support

In many DCIs accessing resources requires user authentication, and, unfortu-
nately, different DCIs require different types of authentication mechanisms. If a
gateway is to support access to different kinds of DCIs, then it should support all the
user authentication methods required by the different DCIs. These methods include,
for example, X509 certi cate proxy management.

Chapter 6 “ WS-PGRADE/gUSE security ” describes the major authentication
methods and their support in the WS-PGRADE/gUSE SG framework.
Users typically want to submit jobs to the different DCIs, and hence the job
submission mechanism is a basic service in every science gateway. Again, different
DCI types implement different types of job submission protocols, and a generic
gateway framework should be prepared to handle all these different kinds of protocols.
The WS-PGRADE/gUSE SG framework contains a generic job submission service
that can submit jobs to all the major DCI types. This service, called the DCI Bridge, is
described in detail in Chap. 4 . Other SG frameworks also support access to several
DCIs, but in a much more restricted way than is supported in WS-PGRADE/gUSE.
Jobs require access to data storage when they are executed. In many cases the
different DCIs apply different storage access protocols, which also cause dif

cate management and certi

culties
for gateway developers who must cope with the variety of these protocols. Exe-
cuting a job in a certain DCI can require access to data storage maintained in other
DCIs. To solve these problems, SCI-BUS developed the Data Avenue service that