Cloud Flashcards
What is Cloud Computing?
Cloud Computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (like networks/ servers/ platform/ storage/ services/ applications) that can be rapidly provisioned and released with minimal service provider interaction.
It has
5 essential characteristics
4 deployment models
3 service models
What are the traditional deployment models?
(1) On-premise:
- all the services, hardware equipments and their managements are owned by same party
(2) Colocation:
- server, storage and network hardware is owned by main party but their services and managements are rented from an external vendor
What is server virtualization?
In traditional IT, if a party required three servers for three categories like application (say Email), database and web, then three physical servers with their own OS and memory setup were installed. This increased operation cost and was not effective usage of resources.
Server virtualization is the process of dividing a physical server into multiple unique and isolated virtual servers using a software called Hypervisor to improve its ability and reduce operating costs. The virtual servers share the hardware but their OSs could be different.
What are the 2 types of hypervisors?
Type 1 (bare metal): they run directly on system hardware (VMWare ESXi, RedHat KVM); generally used in Data Centers
Type 2: they run on an already existing host OS (Oracle VirtualBox); generall used on PCs
What are the 5 essential characteristics of Cloud Computing?
- On-demand self service
- Rapid Elasticity
- Broad Network Access
- Resource Pooling
- Measured Service
Explain the characteristic: On-demand self service
Consumer can unilaterally provide computing capabilities (like server time, network, storage etc) as needed automatically without requiring service provider interaction.
Explain the characteristic: Rapid Elasticity
The computing resources can be elastically provisioned and released to scale rapidly outward and inward in proportion with demand.
The capabilities available for consumer appear to be unlimited and can be adjusted any time.
Explain the characteristic: Broad Network Access
The computing resources are available over a wide range of network and accessed through standard devices (mobile phones, laptops, tablets, computers etc)
Explain the characteristic: Resource Pooling
The provider’s computing resources are pooled to serve multiple consumers in a multi-tenant model, with different physical and virtual resources being dynamically allocated and released per consumer demands.
Explain the characteristic: Measured Service
Service providers automatically control and optimize the resource usage by using a metering capability at some level of abstraction appropriate to the type of service.
The resource usage is monitored, controlled and reported to the consumer in transparent fashion.
What are the three service models of Cloud Computing? What do they define?
The 3 models are:
(1) IaaS (Infrastructure as a Service)
(2) PaaS (Platform as a Service)
(3) SaaS (Software as a Service)
They define the customer and provider ares of responsibilities and at what level the customer gains access.
What services are managed by consumer and provider in IaaS?
In IaaS,
Consumer manages application, data, middleware and part of OS
Provider manages virtualization, servers, storage and network services.
What services are managed by consumer and provider in PaaS?
In PaaS,
Consumer manages only application and data
Provider manages middleware, OS, virtualization, servers, storage and network services.
What services are managed by consumer and provider in SaaS?
In SaaS,
Provider manages everything- application, data middleware, OS, virtualization, servers, storage and network services.
Consumer manages nothing.
What is IaaS?
Infrastructure as a Service (IaaS) is a cloud service model where consumer is provided with storage, servers, network and other fundamental computing resources such that consumer can run and deploy any software on it. Consumer does not manage underlying infrastructure.
AWS and Microsoft Azure provide IaaS facilities.
