The ABCs of cloud computing
By SearchCloudComputing.com staff 16-Jun-2010
From Amazon's Elastic Compute Cloud to Microsoft's Windows Azure, we've collected the best cloud definitions to provide a one-stop resource for anyone on the lookout for a cloud computing reference tool.
Cloud computing glossary, A-Z
Amazon Elastic Compute Cloud (EC2): Amazon's EC2 is a cloud computing service that allows users to deploy and run their applications on rented virtual computers. Users can boot what are called Amazon Machine Images and create an instance, also known as a virtual machine, and pay for the amount of computing power they need by the hour. Amazon EC2 uses Xen virtualization, and the service allows users to adapt to changing performance and capacity needs with an auto-scaling function.
Amazon Simple Storage Service: Amazon's S3 is a cloud storage service that provides scalable, unlimited online archiving and backup for Amazon Web Services users. As of early March, Amazon S3 had stored more than 100 billion objects.
Application programming interface (API): An API is set of programming instructions that cloud computing providers release to developers in order to allow for the creation and deployment of applications on their cloud services. APIs are software-to-software interfaces that accelerate the application development process.
Business-as-a-Service: Business-as-a-Service is a cloud model which relates to the delivery of a secured and end-to-end cloud computing solution that articulates clear business/operationality benefits and viability.
Cloud backup: Cloud backup is the concept of sending copies of your data to an off-site server for backup storage. Enterprises have proven reluctant to adopt cloud backup for pertinent data, as security concerns and fears about storing critical information in the cloud persist. Several prominent cloud backup services are Amazon S3, Asigra and EMC's Mozy.
Cloud cartography: Cloud cartography is a strategy designed to pinpoint the physical locations of Web servers hosted on a third-party cloud computing service. The goal would be to map the service provider's infrastructure in order to identify where a particular virtual machine resides. This scheme was discovered during a study carried out on Amazon Web Services by researchers from MIT and the University of California, San Diego.
Cloud computing: Cloud computing is a general term for anything that involves delivering hosted services over the Internet. These services are broadly divided into three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams.
The National Institute of Standards and Technology (NIST) of the US government defines cloud computing as "a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model promotes availability and is composed of five essential characteristics, three service models, and four deployment models."
A cloud service has three distinct characteristics that differentiate it from traditional hosting. It is sold on demand, typically by the minute or the hour; it is elastic -- a user can have as much or as little of a service as they want at any given time; and the service is fully managed by the provider (the consumer needs nothing but a personal computer and Internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed Internet and a weak economy, have accelerated interest in cloud computing.
A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.) A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people. When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services.
Cloud Security Alliance: The Cloud Security Alliance (CSA) is an organization created to promote security best practices for cloud computing providers. Headed by executive director Jim Reavis and technical director Chris Hoff, the CSA claims such prominent members as AT&T, CA, Cisco, Google, Rackspace and Microsoft.
Distributed denial-of-service attack (DDOS): On the Internet, a distributed denial-of-service (DDoS) attack is one in which a multitude of compromised systems attack a single target, thereby causing denial of service for users of the targeted system. The flood of incoming messages to the target system essentially forces it to shut down, thereby denying service to the system to legitimate users.
A hacker (or, if you prefer, cracker) begins a DDoS attack by exploiting a vulnerability in one computer system and making it the DDoS "master." It is from the master system that the intruder identifies and communicates with other systems that can be compromised. The intruder loads cracking tools available on the Internet on multiple -- sometimes thousands of -- compromised systems. With a single command, the intruder instructs the controlled machines to launch one of many flood attacks against a specified target. The inundation of packets to the target causes a denial of service.
While the press tends to focus on the target of DDoS attacks as the victim, in reality there are many victims in a DDoS attack -- the final target and as well the systems controlled by the intruder.
Elasticity: Elasticity in cloud computing refers to the ability of a provider or an application to grow and shrink the amount of IT infrastructure as needed to meet demand. Elasticity is considered a key cloud feature because it reduces the need of an organization to carry overhead or spare capacity.
Force.com: Force.com is the Platform-as-a-Service offering from Salesforce.com. With Apex Code, Salesforce.com's on-demand programming language, Force.com developers can create hosted applications and integrate client-side applications with Apex-based hosted components.
Google App Engine: Google App Engine is the Platform-as-a-Service offering from the search giant. The development platform is free up to a certain level of used resources; fees are then charged for additional storage, bandwidth or CPU cycles. Targeted at Web developers and Web hosting applications, the only programming languages currently supported by App Engine are Python and Java.
Hybrid cloud: A hybrid cloud is a cloud model that combines the advantages of public and private cloud computing environments. The popularity of hybrid clouds continues to grow as enterprises look to maintain the reliability of in-house data security while still benefiting from the scalability of public cloud.
Infrastructure-as-a-Service: Infrastructure-as-a-Service (IaaS) is a pay-per-use service where a cloud computing provider offers storage space, software and network equipment as consumable resources. IaaS offerings include Amazon EC2, GoGrid and the Rackspace Cloud.
Man-in-the-middle (MitM) attack: A man-in-the-middle (MitM) attack is an exploit in which an intruder intercepts communications between two parties, usually an end user and a website. The attacker can use the information accessed to commit identity theft or other types of fraud.
Users can protect themselves from a traditional man-in-the-middle attack by refraining from logging into sites where sensitive data is maintaned while on a public network. However, a variation on that exploit, called an "active man-in-the-middle attack" makes it possible for an intruder to access information for any site that the user logs into at other times.
Multi-tenancy: Multi-tenancy is the ability of one platform or piece of computing infrastructure to hold more than one application, virtual machine or process at a time, for multiple users. A cloud computing envrionment that is accessible to all users defines a multi-tenant environment.
Platform-as-a-Service: Platform-as-a-Service (PaaS) is a cloud computing model through which a computing platform is delivered to users via the Web. PaaS is often used for the development, deployment and hosting of applications. PaaS offerings include Microsoft Azure, Force.com and Google App Engine.
Private cloud: Private cloud is an in-house cloud computing option that offers hosted services to a limited number of people from behind an organization's firewall. Enterprises are showing greater and greater interest in private clouds, as concerns about cloud computing security have led many organizations to value the dependability of an on-premise cloud option.
Public cloud: Public cloud is any third-party service that offers storage and computing power over the Internet in a scalable, pay-per-usage fashion. Despite being the standard cloud computing model, the enterprise has been slow to accept public cloud over private cloud due to questions about security and compliance issues.
Rackspace Cloud: Rackspace Cloud, which includes the Cloud Files storage service and Cloud Servers infrastructure service, is the hosting provider's public cloud computing offering. Headed up by president and CSO Lew Moorman, Rackspace's cloud service does battle with behemoth Amazon Web Services by promising "fanatical support to its committed group of users."
RightScale Cloud Management Platform: The Cloud Management Platform is the crown jewel in RightScale's collection, a multi-provider cloud management service that runs on both Amazon Web Services and Rackspace. With founder and CTO Thorsten von Eicken at the helm, RightScale has its hand in more cloud computing matters than arguably any other company.
SAS 70: SAS 70 (the Statement on Auditing Standards No. 70) defines the standards an auditor must employ in order to assess the contracted internal controls of a service organization. Service organizations, such as hosted data centers, insurance claims processors and credit processing companies, provide outsourcing services that affect the operation of the contracting enterprise. The SAS 70 was developed by the American Institute of Certified Public Accountants (AICPA) as a simplification of a set of criteria for auditing standards originally defined in 1988.
Under SAS 70, auditor reports are classified as either Type I or Type II. In a Type I report, the auditor evaluates the efforts of a service organization at the time of audit to prevent accounting inconsistencies, errors and misrepresentation. The auditor also evaluates the likelihood that those efforts will produce the desired future results. A Type II report includes the same information as that contained in a Type I report; in addition, the auditor attempts to determine the effectiveness of agreed-on controls since their implementation. Type II reports also incorporate data compiled during a specific time period, usually a minimum of six months.
Scalability: Scalability in cloud computing refers to the ability of a provider or an application to instantly and automatically provision compute capacity to meet spikes in demand.
Service level agreements (SLAs): A service level agreement is the contract that quantifies what the vendor's service must present and guarantees the customer certain service-related percentages and benchmarks. In situations involving cloud computing, SLAs promise certain cloud-based costs and ensure acceptable levels of service availability.
Software-as-a-Service: Software-as-a-Service (SaaS) is a software distribution model that provides applications to customers via the Internet. The most commonly used form of cloud computing, SaaS continues to grow as Web services and service-oriented architectures advance. The top purveyors of SaaS are NetSuite, Adobe and Salesforce.com.
Virtualization: Virtualization technology enables multiple virtual machines to run on a single physical host, with each virtual machine sharing the resources of that hardware across multiple environments.
Virtual machine: A virtual machine (VM) is an environment, usually a program or operating system, which does not physically exist but is created within another environment. In this context, a VM is called a "guest" while the environment it runs within is called a "host." Virtual machines are often created to execute an instruction set different than that of the host environment. One host environment can often run multiple VMs at once. Because VMs are separated from the physical resources they use, the host environment is often able to dynamically assign those resources among them.
VMforce: VMforce is the Java PaaS offering from VMware and Salesforce.com. Unveiled after much speculation, VMforce is aimed at SaaS and Web services developers. The major components of VMforce are VMware's Spring platform -- and its community of Java developers -- and Salesforce.com's Force.com platform.
Windows Azure: Windows Azure is Microsoft's cloud computing platform. Launched in January 2010, Microsoft often updates a list of case studies to show how its numerous customers are using the cloud. Microsoft's cloud platform contains the Azure operating system, the SQL Azure database service and its AppFabric application connectivity service.