Mumbai University >Information Technology>Cloud Computing

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Elastic Utility Computing Architecture Linking Your Programs to Useful Systems

• Eucalyptus is a simple open architecture for implementing cloud functionality at the IaaS level.

• It is specifically designed to be easy to install and maintain in a research setting, and that it is easy to modify, instrument, and extend.

• Eucalyptus can be deployed and executed without modification to the underlying infrastructure.

• Eucalyptus components have well defined interfaces (described by WSDL documents), support secure communication (using WS-Security policies), and rely upon industry-standard Web-services software packages (Axis2, Apache, and Rampart).

• Eucalyptus is a Linux-¬based open source software architecture that implements efficiency-enhancing private and hybrid clouds within an enterprise’s existing IT Infrastructure.

• A Eucalyptus private cloud is deployed across an enterprise’s “on-¬premise” data center infrastructure and is accessed by users over enterprise intranet. Thus sensitive data remains entirely secure from external intrusion behind the enterprise firewall.

Why Eucalyptus?

• Open Source

  You can download it and have the source code at your fingertips.

• Modular

  The Eucalyptus components have well-defined interfaces (via WSDL, since they are web services) and thus can be easily swapped out for custom components.

• Distributed

  Eucalyptus allows its components to be installed strategically close to the needed/used resources. For example Walrus can be installed close to the storage, while the Cluster Controller can be installed close to the cluster it will manage.

• Designed to Perform

  Eucalyptus was designed from the ground up to be scalable and to achieve optimal performance in diverse environments (designed to overlay an existing infrastructure).

• Flexible

  Eucalyptus is flexible and can be installed on a very minimal setup. Yet it can be installed on thousands of cores and terabytes of storage. And it can do so as an overlay on top of an existing infrastructure.

• Compatible

  Eucalyptus is compatible with the most popular and widely used Cloud API currently available: Amazon EC2 and S3.

• Hypervisor Agnostic

  Currently Eucalyptus fully supports KVM and Xen. Additionally, the Enterprise Edition supports the proprietary VMware hypervisor.

• Hybrid Cloud

  The above characteristics makes Eucalyptus easy to deploy as an hybrid cloud. An hybrid cloud combines resources drawn from multiple clouds, typically one private and one public.

Features:

1. Hybrid cloud management

2. Compute

3. Networking

4. Cloud management

Eucalyptus Components:

1. Cloud controller (CLC)

2. Warlus

3. Storage controller

4. Cluster controller

5. VMBroker (optional)

6. Node controller

Cloud controller (CLC)

The Cluster Controller (CC) generally executes on a cluster front-¬‐end machine, or any machine that has network connectivity to both the nodes running NCs and to the machine running the CLC. CCs gather information about a set of VMs and schedules VM execution on specific NCs. The CC also manages the virtual instance network and participates in the enforcement of all nodes served by a single CC must be in the same broadcast domain (Ethernet).

Functions:

• To receive requests from CLC to deploy instances

• To decide which NCs to use for deploying the instances on

• To control the virtual network available to the instances

• To collect information about the NCs registered with it and report it to the CLC

Node controller

• The Node Controller (NC) is executed on every node that is designated for hosting VM instances.NCs control the execution, inspection, and termination of VM instances on the host where it runs, fetches and cleans up local copies of instance images (the kernel, the root file system, and the ramdisk image), and queries and controls the system software on its node (host OS and the hypervisor) in response to queries and control requests from the cluster controller. The Node controller is also responsible for the management of the virtual network endpoint.

Functions:

• Collection of data related to the resource availability and utilization

• on the node and reporting the data to CC

• Instance life cycle management

Storage Controller (SC)

• The Storage Controller (SC) provides functionality similar to the Amazon Elastic Block Store (Amazon EBS). The SC is capable of interfacing with various storage systems (NFS, iSCSI, SAN devices, etc.).

Walrus

• Walrus allows users to store persistent data, organized as buckets and objects. You can use Walrus to create, delete, and list buckets, or to put, get, and delete objects, or to set access control policies. Walrus is interface compatible with Amazon’s Simple Storage Service (S3), providing a mechanism for storing and accessing virtual machine images and user data.

VMware Broker

• VMware Broker (Broker or VB) is an optional Eucalyptus component, which is available if you are a Eucalyptus Subscriber. VMware Broker enables Eucalyptus to deploy virtual machines (VMs) on VMware infrastructure elements. VMware Broker mediates all interactions between the CC and VMware hypervisors (ESX/ESXi) either directly or through VMware vCenter.

Modes of operation Eucalyptus supports four modes of operation in its networking configuration: static mode, managed mode, managed (noVLAN) mode & system mode.

System

In System mode, CC generates and assigns a random MAC address to the VM instance while requesting NC to bring up the instance. NC attaches the VM instance’s virtual NIC to the physical NIC on the node through a bridge. This mode requires that the Nodes are connected to the enterprise network directly. Instances obtain an IP address using DHCP, just as physical machines on the network do.

This mode is very easy to setup as it does not have any additional prerequisites in terms of networking, except for a running DHCP server on enterprise network, and is a good way to get started with Eucalyptus, particularly if you want to set it up on your laptop/desktop to get a basic understanding. This mode of networking is similar to “Bridged Networking” that hypervisors like VMware, VirtualBox etc. offer or like “tap” networking offered by KVM/Qemu.

Static

Static mode offers the Eucalyptus administrator more control over VM IP address assignment than System mode does. In this mode, the administrator configures Eucalyptus with a ‘map’ of MAC address/IP Address pairs on CC.

Before requesting NC to raise an instance, CC sets up a static entry within a Eucalyptus controlled DHCP server, takes the next free MAC/IP pair, and passes on to NC, which attaches the virtual NIC of the instance to the physical NIC of the Node through a bridge similar to how it is handled in ‘System’ mode.

This mode of networking is similar to “Bridged Networking” that hypervisors like VMware, VirtualBox etc. offer or like “tap” networking offered by KVM/Qemu.

This mode is useful for administrators who have a pool of MAC/IP addresses that they wish to always assign to their instances without relying on the DHCP server running in the enterprise network.

Note – Running Eucalyptus in System or Static mode disables some of the following key functionalities that would make an enterprise deployment more manageable:

• Ingress filtering for the instances ( Security Groups )

• User Controlled dynamic assignment of IPs to instances ( Elastic IPs )

• Isolation of network traffic between instances VMs

Managed

Managed mode is the most feature rich mode offered by Eucalyptus. In this mode, the Eucalyptus administrator defines a large network (usually private and unroutable) from which VM instances will draw their IP addresses. As with Static mode, CC will maintain a DHCP server with static mappings for each instance that is raised and allocate the right IPs at the time of requesting an NC to raise the instance.

Managed mode implements ‘security groups’ for ingress filtering and isolation of instances. The user specifies a security group to which the new instance should be associated with, at the time of requesting a new instance. CC allocates a subset of the entire range of IPs to each security group in such a way that all the instances raised to be a part of the same security group use IPs from the same subset.

The user can define ingress filtering rules at the ‘security group’ level. More on this in the chapter on Security. In addition, the administrator can specify a pool of public IP addresses that users may allocate, either while raising the instances or later at run-time. This functionality is similar to ‘elastic IPs’ of AWS.

Eucalyptus administrators who need to implement require security groups, elastic IPs, and VM network isolation must use this mode.

Managed NOVLAN

This mode is identical to MANAGED mode in terms of features (dynamic IPs and security groups), but does not provide VM network isolation. Eucalyptus administrators who want dynamic assignable IPs and the security groups, but are not in a position to run on a network that allows VLAN tagged packets or those who do not have a need for VM network isolation can use this mode