DCI Bridge: Executing WS-PGRADE Workflows in Distributed Computing Infrastructures - Science Gateways for Distributed Computing Infrastructures - page 55

which can distribute the incoming jobs in a treelike arrangement to other DCI
Bridges. The outline of the load-balancing scenario is shown in Fig. 4.2 . The core
gUSE services are aware of only one DCI Bridge installation. Although this DCI
Bridge service is not connected to any DCI, it may forward the jobs it receives to
other DCI Bridge deployments as they are using the same submission interface and
job description language. In this way the central DCI Bridge service may distribute
the incoming jobs among the other services of which it is aware. After the jobs are
distributed, they have the possibility to report job status back to the central gUSE
services using the callback JSDL extension we described at the beginning of this
section.

4.3 Internal Architecture and Main Components
of the DCI Bridge

The DCI Bridge contains a set of components as shown in Fig. 4.3 . All components
of the DCI Bridge must run within a generic web container (such as Tomcat or
Glass sh).

The DCI Bridge can be called by the BES Web Services Description Language
(WSDL) and it executes the operations de

ned by the Open Grid Services Archi-
tecture (OGSA) Basic Execution Service (BES) 1.0 speci cation on different

Fig. 4.3 Internal architecture of the DCI Bridge