Redundancy is a central theme of all cloud technologies. It was a natural extension of virtualization, which allowed the encapsulation of entire servers into a single file, making them easy to replicate and move within clusters of physical servers. Virtualization, in fact, has been extended to the hypervisors themselves, which provide the interface between virtual servers and the “bare metal” physical servers upon which they run. The potential of this advance is currently being explored and has already increased the efficiency of some data centers.
The ability to quickly and easily duplicate servers, then, gave rise to the ability to “spin up” new servers to meet the demands of unusually heavy workloads. These additional virtual servers could be spawned on underutilized hardware to provide optimum performance for the busy sites with no performance penalty for those sites already on the newly conscripted hosts. But it was noticed that there was another, more important benefit of having multiple copies of a server, in that when one server in a cluster failed, service could continue uninterrupted on another virtual server hosted by another physical server in the cluster. Thus was born the idea of redundant servers to achieve the phenomenal guaranteed “uptime reliabilities” that we currently see for virtual hosting. While 99.9% is a typical promise for that parameter, typically, the realized reliabilities in modern data centers are far greater.
While nothing is free, some things cost very little, and the trade-off in this situation is obviously the additional storage requirements of the redundancy upon which all this is predicated. Data centers have found that the optimum economies are achieved with RAID arrays, whose redundancy and error detection and correction allow them to be comprised of relatively inexpensive hard disks while still maintaining superior data integrity.
Redundancy, then, can be described as the very cornerstone of the data integrity and reliability inherent in modern cloud computing. For more information about cloud computing and its advantages, read our blog regularly, and when your company is ready to soar into the clouds, contact us and let us make the transition an easy one for you.