Clusters Terminology Index

availability

A term used to indicate the probability of a system or capability of a system to remain operable and service requests. Availability takes into account the operating time of the system or system capability and the time required for repairs or maintenance. It is typically expressed in terms the percentage of time the system remains in service (99.999% or 99.9999%, implying a service downtime of 5 minutes or 30 seconds per year).

cluster

A cluster is a group of separate computers that are connected together and are used as a single computing entity to provide a service or run an application for the purposes of scalability, load balancing, and distribution of tasks.

failover

An operational mode where the function of a system component is assumed by a standby component when the primary system component becomes unavailable because of failure or scheduled down time.

heartbeat

A mechanism by which one component determines whether another component is functioning.

node

A single unit/board, possibly with multiple CPUs.

redundancy

Duplication of hardware or data paths which exist to prevent the failure of the active system upon failure of the duplicated component.

reliability

The probability that a system or a capability of a system will continue to function without failure under given conditions for a specified period of time.

Other Terms

Patch Lifecycle Manager (PLM)

A source manager which provides a central point for tracking the lifecycle of patches against a source tree.

Scalable Test Platform (STP)

Test harness for building reproducible test environments, executing tests and collecting results.

System Under Test (SUT)

The system which we will be executing any binary regression tests on.

Use Cases

Hypothetical scenarios as to how end users will exercise and benefit from use of clusters.