Cluster Controller (CC)
A cluster is equivalent to an AWS availability zone, and a single Eucalyptus cloud can have multiple clusters. The Cluster Controller (CC) is written in C and acts as the front end for a cluster within a Eucalyptus cloud and communicates with the Storage Controller (SC) and Node Controller (NC). The CC manages instance (i.e., virtual machines) execution and Service Level Agreements (SLAs) per cluster.
Storage Controller (SC)
The Storage Controller (SC) is written in Java and is the Eucalyptus equivalent to AWS Elastic Block Store (EBS). The SC communicates with the Cluster Controller (CC) and Node Controller (NC) within the distributed cloud architecture and manages Eucalyptus block volumes and snapshots to the instances within its specific cluster. If an instance requires writing persistent data to memory outside of the cluster, it would need to write to the backend storage, which is available to any instance in any cluster. The SC interfaces with storage systems, including local, NFS, iSCSI, and SAN.