The diagram above depicts a high level architecture of the WSO2 Cloud Controller. The Cloud Controller is a WSO2 Carbon based server that has several architectural components, that are namely,
...
The Axiom Xpath based parser is responsible for parsing all kinds of *.xml configuration files of the Cloud Controller.
Topology publisher
We use a central location such as the Cloud Controller to maintain the topology configuration. The topology configuration refers to the information on the various service clusters present in the Cloud environment.
To view a sample file see Sample Topology Configuration
Keeping this information in the Cloud Controller alone is not sufficient as this configuration is needed in other locations as well, such as the Elastic Load Balancer (ELB), Artifact Distribution Coordinator (ADC) and other locations. As a result, the Cloud Controller syncs the topology with the other components. The following image explains how the topology synchronization takes place:
...
This layer is the jclouds API jclouds is an open source library that helps you get started in the cloud. The jclouds API gives you the freedom to use portable abstractions or cloud-specific features. For more information on jclouds got go to http://www.jclouds.org/
...