WS-PGRADE/gUSE and Clouds - Science Gateways for Distributed Computing Infrastructures - page 97

software in the background. Table 7.1 summarizes the properties and requirements
of the IaaS and SaaS operation models in the WS-PGRADE/gUSE and CBP
scenarios.
As can be seen in Table 7.1 , IaaS is a better choice than SaaS, given that we trust
that the users will not submit malicious executables to the provided cloud resources.
In turn, the SaaS model provides better security, but the overhead on con guration

is notable. From the users point of view, IaaS is only required if they would like to

run their own executables; otherwise they will be

'

fine with the SaaS model.
In the case of existing WS-PGRADE/gUSE workflows con gured to run on

non-cloud DCIs with executables provided by the users, the IaaS model offers a
quick way to migrate the existing workflows to cloud resources: users simply have
to recon gure the workflow nodes to run on the CBP with the wrapper application.

7.4 Architecture

The high-level architecture of the WS-PGRADE/gUSE and CBP integration is
shown in Fig. 7.2 . WS-PGRADE with the different portlets and application-speci c

views is located at the top of the architecture. The user can connect to WS-PGRADE/
gUSE to run workflows, or to the CBP directly to run single jobs. Users can use the

Fig. 7.2 WS-PGRADE/gUSE and CloudBroker integration architecture