VIT’s very own Cloud Computing Centre #3

It’s now time for the third article in the series of articles on cloud computing.

This time I will cover Eucalyptus, a Linux based , open-source software infrastructure for the implementation of cloud computing on computer clusters which provides an interface that is compatible with the Amazon EC2 service.

A Eucalyptus cloud setup consists of five types of components. The cloud controller (CLC) and "Walrus" are top-level components, with one of each in a cloud installation. The cloud controller is a Java program that offers EC2-compatible SOAP and "Query" interfaces, as well as a Web interface to the outside world. In addition to handling incoming requests, the cloud controller performs high-level resource scheduling and system accounting. Walrus, also written in Java, implements bucket-based storage, which is available outside and inside a cloud through S3-compatible SOAP and REST interfaces.

Top-level components can aggregate resources from multiple clusters (i.e., collections of nodes sharing a LAN segment, possibly residing behind a firewall). Each cluster needs a cluster controller (CC) for cluster-level scheduling and network control and a "storage controller" (SC) for EBS-style block-based storage. The two cluster-level components would typically be deployed on the head-node of a cluster. Finally, every node with a hypervisor will need a node controller (NC) for controlling the hypervisor. CC and NC are written in C and deployed as Web services inside Apache; the SC is written in Java. Communication among these components takes place over SOAP with WS-security.

Many instructions in this article refer to a single-cluster installation, in which all components except NC are co-located on one machine, which we refer to as front-end. All other machines, running only NCs, will be referred to as nodes. In more advanced configurations, such as those with multiple CCs or with Walrus deployed separately, the front-end will refer to just the machine running the CLC.

Eucalyptus can be installed from source or using a set of packages (RPM and DEB). The former method is more general and should work on practically any Linux system, the latter is easier but will only work on the distributions that Eucalyptus support. As of 1.6 they are:

CentOS 5.4,
Debian squeeze,
OpenSUSE 11, and
Ubuntu 9.04 "Jaunty" and 9.10 "Karmic".

To install eucalyptus on CentOS refer this link : http://open.eucalyptus.com/wiki/EucalyptusInstallationCentos_v1.6

For configuration details refer the following links in order:

http://open.eucalyptus.com/wiki/first-time-setup-16
http://open.eucalyptus.com/wiki/hypervisor-configuration
http://open.eucalyptus.com/wiki/EucalyptusNetworking_v1.6
Once Eucalyptus is installed, the management tools called Euca2ools should be installed. For this refer to http://open.eucalyptus.com/wiki/Euca2oolsCentosInstall_v1.1

To troubleshoot, look at the eucalyptus forums.  You can also ask your questions by commenting on the article.

Next time, we will look into cloud management using Euca2ools.