Redundant Array of Inexpensive Servers


A Redundant Array of Inexpensive Servers or Redundant Array of Independent Nodes is the use of multiple servers to provide the same service in such a way that service will still be available if the servers fails. The term may imply some kind of load balancing between the servers.
RAIS stripes and mirrors application code and memory across an array of ordinary servers using the standard RAID schemata of level 0, level 1, level 5, level 1+0. This is possible through the invention of a radical new memory management system called Versioned Memory.
RAIS provide the benefits of an SMP at the entry cost of clusters.

How does RAIS work.

Therefore, just as RAID stripes and mirrors data across multiple independent disks and code of an application program across multiple independent nodes of a cluster. The applications see only a single logical shared memory which functions as a binary compatible Symmetric Multiprocessor system.

What does RAIS provide?

The main significant benefit is the substantial reduced capital cost providing an alternative solution to migrating to SMP.