The Traditional Server ConceptWeb Server App Server DB Server EMailWindows Linux Linux Windows IIS Glassfish MySQL Exchange 20090909_VirtualizationAndCloud 3
THE TRADITIONAL SERVER CONCEPT• SYSTEM ADMINISTRATORS OFTEN TALK ABOUT SERVERS AS A WHOLE UNIT THAT INCLUDES THE HARDWARE, THE OS, THE STORAGE, AND THE APPLICATIONS.• SERVERS ARE OFTEN REFERRED TO BY THEIR FUNCTION I.E. THE EXCHANGE SERVER, THE SQL SERVER, THE FILE SERVER, ETC.• IF THE FILE SERVER FILLS UP, OR THE EXCHANGE SERVER BECOMES OVERTAXED, THEN THE SYSTEM ADMINISTRATORS MUST ADD IN A NEW SERVER. 20090909_VirtualizationAndCloud 4
THE TRADITIONAL SERVER CONCEPT• Unless there are multiple servers, if a service experiences a hardware failure, then the service is down.• System Admins can implement clusters of servers to make them more fault tolerant. However, even clusters have limits on their scalability, and not all applications work in a clustered environment. 20090909_VirtualizationAndCloud 5
DEFINITIONCLOUD COMPUTING is the delivery ofcomputing as a service rather than a product,whereby shared resources software andinformation are provided to the computersand other devices over a network.Cloud is a large group of interconnectedcomputersCloud here is actually a metaphor of internet
Cloud computing architecture*. Cloud computing can be divided into two sections1. Front end2. back end*. Front end includes client computers*. Back end is the cloud section of the system*. The administrator uses a set of rules called protocolsand uses special kind of softwares called middleware forsmooth running and traffic control*. Middleware allows networked computers tocommunicate with each other.
CLOUD COMPUTING SERVICESCloud computing providers offer their services according to three fundamental models• Infrastructure as a service (IaaS)• platform as a service (PaaS)• software as a service (SaaS)
CLOUD COMPUTING SERVICESIAAS- In this most basic cloud service model, cloud providers offercomputers – as physical or more often as virtual machines –, raw(block) storage, firewalls, load balancers, and networks. Cloudproviders typically bill IaaS services on a utility computing basisPAAS- In the PaaS model cloud providers deliver a computingplatform and/or solution stack typically including operating system,programming language execution environment, database, and webserver.SAAS- In this model, cloud providers install and operate applicationsoftware in the cloud and cloud users access the software fromcloud clients.
ADVANTAGES1.Access you data all the times2.A physical storage centre is no longer needed3.Most have a pay structure that only calls for payment when used4.Relieves burden on IT proffesssional and frees up their time in office5.Easily scalable so companies can add or substract resources based on their own needsDISADVANTAGES1.Less control comes with handling over your data and information2.Dependence on a third party to ensure security and confidentiality of data and information3.Long term dependence on cloud host or maintainance o your information
Conclusion Thus cloud computing provide a super-computingpower .This cloud of computers extends beyond a singlecompany or enterprise. The applications and data served by the cloud areavailable to broad group of users, cross-enterprise and cross-platform.