High Availability

High availability is a system design approach and associated service implementation that ensures a prearranged level of operational performance will be met during a contractual measurement period.

Users want their systems, for example wrist watches, hospitals, airplanes or computers, to be ready to serve them at all times. Availability refers to the ability of the user community to access the system, whether to submit new work, update or alter existing work, or collect the results of previous work. If a user cannot access the system, it is said to be unavailable. Generally, the term downtime is used to refer to periods when a system is unavailable.

Read more about High AvailabilityScheduled and Unscheduled Downtime, Percentage Calculation, Measurement and Interpretation, Closely Related Concepts, System Design For High Availability, Reasons For Unavailability, Costs of Unavailability

Other articles related to "availability, high, high availability":

Communications Server - Industry-managed Standards - HPI and AIS
... These Service Availability Forum (SA Forum) specifications define standard interfaces for telecom platform management and high-availability software ... specification defines the interface between high availability middleware and the underlying hardware and operating system ... Specification (AIS) defines the application programming interface between the high availability middleware and the application ...
Message Plus/Open - Virtualization and High Availability
... like VMware and supports, as standard, high availability cluster solutions including AIX High Availability Cluster Multi-Processing (HACMP), SUN Solaris Cluster and Microsoft ...
SAP Implementation - Implementation Processes - Sizing and Blueprinting
... Identify high availability and disaster recovery requirements The next step is identifying the high availability requirements and the more serious disaster recovery ... so that an organization has a good idea of its actual availability requirements ... The most important factor when designing the data center is availability ...
Communications-based Train Control - Main Features - Risks
... As a result, high availability of CBTC systems is crucial for proper operation, especially if we consider that such systems are used to increase transport capacity and reduce headway ... must then be thoroughly checked to achieve a high robustness in operation ... With the increased availability of the CBTC system, it must also be considered the need for an extensive training and periodical refresh of system operators on the recovery procedures ...
Lustre (file System) - High Availability
... Lustre file system high availability features include a robust failover and recovery mechanism, making server failures and reboots transparent ...

Famous quotes containing the words availability and/or high:

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    Rutherford Birchard Hayes (1822–1893)

    The Forefathers’ day—Pilgrim day. We are at the same high call here today—freedom, freedom for all. We all know that is the essence of this contest.
    Rutherford Birchard Hayes (1822–1893)