Introduction to the WS-PGRADE/gUSE Science Gateway Framework - Science Gateways for Distributed Computing Infrastructures - page 18

systems (MySQL, etc.), and work ow management systems (WS-PGRADE/gUSE,

MOTEUR, etc.). With help of gUSE, scienti c communities can compose and

execute a series of computational or data manipulation steps in a scienti

c appli-

cation on Distributed Computing Infrastructures (DCIs).
This chapter introduces the key features, the architecture, the common user-level
components, and the customization modes of the gUSE framework.

2.2 What gUSE Offers

gUSE provides a transparent, web-based interface to access distributed resources,
extended by a powerful general-purpose work ow editor and enactment system,

which can be used to compose scienti ow

structures (Balasko 2013a). gUSE is the only SG framework in Europe that offers a
comprehensive and

c applications into data- ow based work

ow-oriented framework that enables the devel-
opment, execution, and monitoring of scienti

flexible work

c work ows. In addition, the nodes

of these work ows can access a large variety of different DCIs, including clusters,

grids, desktop grids, and clouds (Kacsuk 2012).
This SG framework can be used by National Grid Initiatives (NGIs) to support
small user communities who cannot afford to develop their own customized SG.
The gUSE framework also provides two Application Programming Interfaces
(APIs), namely the Application-Speci c Module API and the Remote API, to create

application-speci c SGs according to the needs of different user communities.

A relevant requirement in the development of gUSE was to enable the simulta-
neous handling of a very large number of jobs, even in the range of millions, without
compromising the response time at the user interface. In order to achieve this level of
concurrency, the work

ow management back-end of gUSE is implemented based on
the web service concept of Service Oriented Architecture (SOA) (Kacsuk 2012).

2.3 Key Features

Among many other features, the main five capabilities of gUSE are as follows:

1. gUSE is a general-purpose SG framework under which users can access more
than twenty different DCIs 3 via the DCI Bridge service, and six different data
storage types (HTTP, HTTPS, GSIFTP, S3, SFTP, and SRM) via the Data
Avenue service. Both DCI Bridge and Data Avenue were developed as part of
the WS-PGRADE/gUSE service stack, but they can also be used as independent
services enabling their use from other types of gateways and work ow systems.

2. WS-PGRADE/gUSE is a workflow-oriented system. It extends the Directed
Acyclic Graph (DAG)-based work

ow concept with advanced parameter sweep

3

The full list of supported DCIs is in Sect. 2.4 .