!! Eucalyptus Architecture Overview
The architecture of a eucalyptus cloud is fairly similar to that of other cloud systems, such as Amazon's EC2. There are some difference, however, and below the general architecture of a cloud in eucalyptus is introduced.
(:table bgcolor=#FFAAAA :) (:cellnr:) Note (:cellnr:) This page is a work in progress please do not modify it (:tableend:)
!! Cloud Level Components
The cloud level components are those components which manage the cloud as a whole. They are also the public-facing components, and the user's interface into the cloud. The two cloud level components are the Cloud Controller, which handles the management of clusters and provides the interface to the user for managing virtual machines, and Walrus, which handles management of storage.
!!! Cloud Controller
main article: Cloud Controller
The cloud controller is the main interface into the cloud for users. Through the cloud controller, the user can start and stop machines, manage their SSH keys, manage their security settings, and other such functions. The cloud controller also manages availability of different clusters in different zones (clusters need not be in the same geographical locations, for example).
main article: Walrus
Walrus is the component of Eucalyptus that allows you to store your data in the cloud. You can store your data as objects or buckets, which are collections of objects. These data stores are secure, and you as the administrator decides who has access to the data, and what privileges they have (read, write, etc.).
!! Cluster Level Components
Clusters are groups of nodes. In Eucalyptus, unlike amazon's cloud, the availability zones are also at the cluster level.
!!! Cluster Controller
main article: Cluster Controller
The cluster controller acts as the link between nodes and the cloud controller. It schedules the execution of virtual machines on specific nodes in its cluster, and it manages the networking between virtual machines.
!!! Storage Controller
main article: Storage Controller
The storage controller manages storage for the cluster. The storage controller's primary role is to manage storage volumes for the virtual machines in the cluster. The storage controller can use several different systems for storing these files, and the storage controller hides such details from the user. The storage controller handles the storage of virtual machine images for the cluster.
!! Node Level Components
A node is a physical machine that has a node controller and a number of virtual machines.
!! Node Controller
main article: Node Controller
The node controller handles actually starting and stopping individual virtual machines on its own node. It also handles working with system software on the host machine, specifically the operating system and hypervisor. The node controller can also maintain a cache of virtual machine instances