Three service models of cloud computing (IAAS SaaS PAAs)

Source: Internet
Author: User
Recently, when companies are using other cloud services, they need to encapsulate their own cloud services. The following is a warm-up before developing products to learn about the three service models in cloud computing. I also look for them on the Internet,. Please .. According to the definition of the National Institute of Standards and Technology (NIST), which is the most common service model, cloud computing is divided into three service models, in addition, the three layers of differentiation are important from the perspective of user experience:


IAAs is an infrastructure as a service with basic settings as a service. Consumers can obtain services from a complete computer infrastructure over the Internet. For example, AWS, openstack, and cloudstack provide virtual machine computing services. In this mode, users can obtain the virtual machines or storage resources they need from the supplier to load related applications, and the tedious management of these basic settings will be handled by the IAAs supplier. IAAs supports a wide range of applications through virtual machines. The main users of IAAs are system administrators.


It mainly includes Amazon EC2, linode, joyent, rackspace, IBM Blue cloud, and Cisco UCS.


What are IAAs cloud functions? Seven basic IAAs functions are listed in virtualization and cloud computing:

Resource Abstraction: Use resource abstraction to better schedule and manage physical resources.

Load Management: Load management not only enables application operations deployed on the infrastructure to better cope with emergencies, but also makes better use of system resources.

Data Management: For cloud computing, data integrity, reliability, and manageability are basic requirements for IAAs.

Resource deployment: Automate the process from creation to use of the entire resource.

 Security Management: Ensure that basic settings and resources provided by IAAs are accessed and used legally when the main objectives of security management are IAAs.

Billing Management: Detailed billing management allows users to use resources more flexibly.


SAAS is a software-as-a-service, which is usually called the software Operation Service Model in China. It is referred to as the soft camp model and provides software services, such as office365, this software application can be directly used over the Internet without local installation.

Users only need to connect to the network and use a browser to directly run applications on the cloud, without the need to consider installation and other trivial matters, and avoid high initial hardware and software investment. SAAS mainly targets common users.

Main Products

Salesforce sales cloud, Google Apps, zimbra, zoho, IBM Lotus live, and other software similar to browser tomato.

Functions of SAAS

What functions do you need to use to make your products SaaS services available to others?

Access anytime, anywhere: Users can access this SaaS service at any time and anywhere as long as they connect to the network.

Public protocols supported: Public protocols (such as html4/5) are supported for your convenience.

Security Assurance: SaaS providers need to provide certain security mechanisms, not only to put user data stored on the cloud in an absolute security situation, but also to implement certain security mechanisms (such as https) on the client) to protect users.

 Multiple users(Multi-tenant) mechanism, through multi-user mechanism, not only can more economically support a large user scale, but also provide a certain degree of flexibility to meet the special needs of users.


Paas is the abbreviation of platform-as-a-service. consciousness is a platform-as-a-service. With the PAAs mode, you can easily write applications on a development platform that includes sdks, documents, and test environments, whether deployed or running on servers, operating system, network, storage and other resource management concerns, these tedious work is handled by the PAAs supplier, and the PAAs integration rate is amazing, for example, a server running Google App Engine can support thousands of applications. That is to say, Paas is very economical. Paas is primarily intended for developers. The server platform is a business model provided by services. For example, a development platform that can be directly used over the Internet does not require local installation of various development environments.


Google App Engine,, Heroku, and Windows azure platform.

Service functional requirements as PAAs include:

Good Development Environment: Using sdks, IDE, and other tools, you can easily develop and test applications locally.

Rich services: The PAAs platform provides various services to upper-layer applications in the form of APIs.

Automatic Resource Scheduling: The scalability feature not only optimizes system resources, but also automatically adjusts resources to help applications running on them better cope with traffic bursts.

Fine management and monitoring: Through paas, you can manage and monitor the application layer. For example, you can observe the application running status and specific values (such as throughput and time) to better measure the application running status, in addition, you can use the resources consumed by the application for better billing.

What are the three service relationships?

There is no inevitable connection between the three services. Only three different service models are based on the Internet and pay on demand. Just like water, electricity, and gas, there is no connection between them, it cannot be said that there is no contact at all.

However, in the actual business model, the development of paas has indeed promoted the development of SAAS, because after the development platform is provided, the development difficulty of SAAS is reduced.

From the perspective of user experience, the relationship between them is independent, because they face different users.

From a technical point of view, they are not simple inheritance relationships, because SaaS can be based on paas or directly deployed on IAAs, and PAAs can be built on IAAs, it can also be directly built on physical resources.

Shows the relationship between them:

Three Service Modes of cloud computing

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