Since beginning in the hosting business back in 2001, alot has changed. Instead of shared hosting, we now call it cloud hosting. In addition to dedicated server, we now days hear alot about virtualized servers. Instead of websites, we now have applications.
There is alot of hype with any technology that comes along, but the main concepts remain the same. They are either shared or dedicated resources. There is no doubt about it that the cloud in its basic form is a shared resource. Applications are sharing the server running them. Thus Processors, Memory and Disks are all shared among all the users of the system. These users are typically spread among many servers. The term ‘cloud’ is another twist on the term ‘shared’.
However, consider this scenario User A on Server 1 and User B also residing on Server 1. If User B starts using alot of CPU and Disk resources, then User A will be affected regardless of whether this is a shared hosting or cloud hosting.
The only exception are virtualized servers which have their own dedicated memory resources and most of the time dedicated CPU cycles. However, even virtualized servers suffer from the shared disk problem. If the SAN (Storage Area Network) or Storage Appliance that are used by the servers degrade in performance, then everyone connected to that shared resource will be affected.
The one last option is what the dedicated cloud. This is a set of hardware (storage/firewall/phsyical servers) dedicated for your environment. Thus, the risk of perofrmance degradation is only limited to the type of servers and applications running within that dedicated cloud.
In our environment, we focus on segregated cloud hosting. We split our resources among physical servers with dedicated storage resource for each server. Ensuring that each server is loaded with certain number of virtual machines that each one will get its fair share without inconveniencing the other users on the system. If an application consumes more than its fair share of resources, that virtual machine is moved over to a server with more dedicated resources for it.
Due to the fact we do divide our cloud into segmented physical servers, the likely chance of a server over loading the other machines is very slim compared to a SAN system that has hundreds or perhaps thousands of users.
In our cloud or shared hosting, reliability, performance and security come first.