Cache Array Support (CAS)™

CAS provides the ability to cluster repository subsystems to form one logical document warehouse. The array can consist of hundreds of subsystems with a total capacity of billions of active documents.

Mechanics

A cache array is a collection of subsystems and the high-speed space managed by those subsystems. The first subsystem is said to be the primary subsystem; all other subsystem are called auxiliary subsystems. Any number of subsystems may be a member of the cache array. Special directives placed in the QXCNTRL file describe the array members, order of consideration for space requests, the actions to be taken in the event that an auxiliary subsystem is in a “down” state, and whether the primary subsystem is off limits for general space requests. Auxiliary array members may be shared across filesets.

The CAS layer is positioned between space consumers and space providers. It acts as an allocation controller accepting requests for space and associating those requests with the optimum provider in the array. Directives permit space assignment based on percentage utilization, sequential (back to front) allocation, and free space.

Advantages

The primary advantages may, on the surface, seem to be related specifically to capacity. It is true that CAS addresses capacity issues. More importantly, it enhances the management capabilities of the system by letting you respond rather than react to potential failures relating to spikes in system volume.

Business Case

CAS gives you absolute flexibility to respond to changing output management workload requirements while reducing management overhead.