text: **12.1 Scalability, reliability, and availability defined**
  
  This section defines scalability, reliability, and availability and how they relate to a Content 
  Manager OnDemand system. 
  
  **Scalability**
  Scalability is the ability of a Content Manager OnDemand system to handle a growing amount 
  of work with no performance degradation. A Content Manager OnDemand system’s 
  performance improves with the addition of hardware and network resources and therefore is 
  defined as a scalable system. Two types of scalability are defined: 
  
  (cid:2)*Horizontal scalability*(or scale out): This type of scalability is achieved by adding more 
  
  nodes, systems, or logical partitions (LPARs) to a Content Manager OnDemand instance. 
  An example of horizontal scalability is adding more object servers to a Content Manager 
  OnDemand instance. 
  
  (cid:2)*Vertical scalability*(or scale up): This type of scalability is achieved by adding more 
  
  resources to a single node in a Content Manager OnDemand instance. Typically, this type 
  of scalability involves faster processors, more processors, memory, disks, or networking 
  hardware. 
  
  Content Manager OnDemand is both horizontally and vertically scalable. 
  
  **Reliability**
  Reliability is the ability of Content Manager OnDemand to perform and maintain functionality 
  during regular workloads and during peak workloads. Peak workloads might occur regularly 
  (for example, when everyone signs on at 9:00 a.m.) or periodically (at the end of the month 
  when more processing than usual occurs). Or, peak workloads might occur sporadically (for 
  example, when a special event occurs, such as a sales drive that results in more users using 
  the system). 