DCI Bridge: Executing WS-PGRADE Workflows in Distributed Computing Infrastructures - Science Gateways for Distributed Computing Infrastructures - page 61

4.5 Direct Cloud Access via the DCI Bridge

4.5.1 Concept of Direct Cloud Access

The main goal of the direct cloud solution is to access directly cloud infrastructure
(without using CloudBroker Platform) and launch in the cloud any type of services/
jobs de ned previously in WS-PGRADE workflows. The direct cloud solution

works according to a Master/Slave arrangement of DCI Bridges (Sect. 4.2.2 ) and
does not use the CloudBroker Platform service to access cloud infrastructure. The
direct cloud access is based on the capability of creating distributed DCI Bridge
deployment and on job forwarding from master to slave DCI Bridge(s). The master
DCI Bridge that directly connects to gUSE, forwards jobs through Amazon Elastic
Compute Cloud (EC2)-based front-end cloud service to the slave DCI Bridge
located in the cloud. Technically, the master DCI Bridge starts the virtual machine
(VM) via EC2-based service. The started VM contains a Slave DCI Bridge that is
con gured to run jobs via the local submission facility, i.e., in the VM where the

slave DCI Bridge runs. The VM containing the slave DCI Bridge should previously
be created and saved as an image in the cloud repository (Fig. 4.6 ). This solution
can be applied on all Amazon EC2-compatible cloud services.

Fig. 4.6 The roles and processes of the direct cloud access solution