Learn about cloud computing concepts, advantages and disadvantages of cloud computing, cloud computing deployment models like IaaS, PaaS, SaaS
What Is Cloud Computing?
Cloud computing is the on-demand delivery of compute power, database storage, applications, and other IT resources through a cloud services platform via the internet with pay-as-you-go pricing. Cloud computing is providing developers and IT departments with the ability to focus on what matters most and avoid undifferentiated work like procurement, maintenance, and capacity planning. As cloud computing has grown in popularity, several different models and deployment strategies have emerged to help meet specific needs of different users. Each type of cloud service, and deployment method, provides you with different levels of control, flexibility, and management. Understanding the differences between Infrastructure as a Service, Platform as a Service, and Software as a Service, as well as what deployment strategies you can use, can help you decide what set of services is right for your needs.
Cloud computing-
- Uses Internet technologies to offer scalable and elastic services. The term “elastic computing” refers to the ability of dynamically acquiring computing resources and supporting a variable workload.
- The resources used for these services can be metered and the users can be charged only for the resources they used.
- The maintenance and security are ensured by service providers.
- The service providers can operate more efficiently due to specialization and centralization.
- Lower costs for the cloud service provider are past to the cloud users.
- Data is stored: closer to the site where it is used but in a device and in a location-independent manner.
- The data storage strategy can increase reliability, as well as security, and can lower communication costs.
Who is using cloud computing?
Six Advantages and Benefits of Cloud Computing
- Trade capital expenses for variable expense
- Benefit from massive economies of scale
- Stop guessing capacity
- Increase speed and agility
- Stop spending money on running and maintaining data centers
- Go global in minutes
Why cloud computing could be successful when other paradigms have failed?
- It is in a better position to exploit recent advances in software, networking, storage, and processor technologies promoted by the same companies who provide cloud services.
- It is focused on enterprise computing; its adoption by industrial organizations, financial institutions, government, and so on could have a huge impact on the economy.
- A cloud consists of a homogeneous set of hardware and software resources.
- The resources are in a single administrative domain (AD). Security, resource management, fault-tolerance, and quality of service are less challenging than in a heterogeneous environment with resources in multiple ADs.
Types of Cloud Computing
Infrastructure as a Service (IaaS)
Infrastructure as a Service, sometimes abbreviated as IaaS, contains the basic building blocks for cloud IT and typically provide access to networking features, computers (virtual or on dedicated hardware), and data storage space. Infrastructure as a Service provides you with the highest level of flexibility and management control over your IT resources and is most similar to existing IT resources that many IT departments and developers are familiar with today.- The user is able to deploy and run arbitrary software, which can include operating systems and applications.
- The user does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of some networking components, e.g., host firewalls.
- Services offered by this delivery model include: server hosting, Web servers, storage, computing hardware, operating systems, virtual instances, load balancing, Internet access, and bandwidth provisioning.
Platform as a Service (PaaS)
Platforms as a service remove the need for organizations to manage the underlying infrastructure (usually hardware and operating systems) and allow you to focus on the deployment and management of your applications. This helps you be more efficient as you don’t need to worry about resource procurement, capacity planning, software maintenance, patching, or any of the other undifferentiated heavy lifting involved in running your application.
- Allows a cloud user to deploy consumer-created or acquired applications using programming languages and tools supported by the service provider.
- The user:
- Has control over the deployed applications and, possibly, application hosting environment configurations.
- Does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage.
- Not particularly useful when:
- The application must be portable.
- Proprietary programming languages are used.
- The hardware and software must be customized to improve the performance of the application.
Software as a Service (SaaS)
Software as a Service provides you with a completed product that is run and managed by the service provider. In most cases, people referring to Software as a Service are referring to end-user applications. With a SaaS offering you do not have to think about how the service is maintained or how the underlying infrastructure is managed; you only need to think about how you will use that particular piece of software. A common example of a SaaS application is web-based email where you can send and receive email without having to manage feature additions to the email product or maintaining the servers and operating systems that the email program is running on.
- Applications are supplied by the service provider.
- The user does not manage or control the underlying cloud infrastructure or individual application capabilities.
- Services offered include:
- Enterprise services such as: workflow management, group-ware and collaborative, supply chain, communications, digital signature, customer relationship management (CRM), desktop software, financial management, geo-spatial, and search.
- Web 2.0 applications such as: metadata management, social networking, blogs, wiki services, and portal services.
- Not suitable for real-time applications or for those where data is not allowed to be hosted externally.
- Examples: Gmail, Google search engine.
Cloud Deployment Models
There is a range of deployment models, from all on-premises to fully deployed in the cloud. Many users begin with a new project in the cloud, and they might integrate some on-premises applications with these new projects in a hybrid architecture. They might decide to keep some legacy systems on-premises. Over time, they might migrate more and more of their infrastructure to the cloud, and they might eventually reach an all-in-the-cloud deployment.
Cloud
A cloud-based application is fully deployed in the cloud and all parts of the application run in the cloud. Applications in the cloud have either been created in the cloud or have been migrated from an existing infrastructure to take advantage of the benefits of cloud computing. Cloud-based applications can be built on low-level infrastructure pieces or can use higher level services that provide abstraction from the management, architecting, and scaling requirements of core infrastructure.
Hybrid
A hybrid deployment is a way to connect infrastructure and applications between cloud-based resources and existing resources that are not located in the cloud. The most common method of hybrid deployment is between the cloud and existing on-premises infrastructure to extend, and grow, an organization's infrastructure into the cloud while connecting cloud resources to internal system. For more information on how AWS can help you with your hybrid deployment, please visit our hybrid page.
On-premises
Deploying resources on-premises, using virtualization and
resource management tools, is sometimes called “private cloud”.
On-premises deployment does not provide many of the benefits of cloud
computing but is sometimes sought for its ability to provide dedicated resources.
In most cases this deployment model is the same as legacy IT
infrastructure while using application management and virtualization
technologies to try and increase resource utilization.
Community Cloud
Challenges for cloud computing
- Availability of service; what happens when the service provider cannot deliver?
- Diversity of services, data organization, user interfaces available at different service providers limit user mobility; once a customer is hooked to one provider it is hard to move to another. Standardization efforts at NIST!
- Data confidentiality and auditability, a serious problem.
- Data transfer bottleneck; many applications are data-intensive.
- Performance unpredictability, one of the consequences of resource sharing.
- How to use resource virtualization and performance isolation for QoS guarantees?
- How to support elasticity, the ability to scale up and down quickly?
- Resource management; are self-organization and self-management the solution?
- Security and confidentiality; major concern.
- Addressing these challenges provides good research opportunities!!
