Definition of High Availability
High Availability (HA) is the ability of a system to perform its function continuously (without interruption) for a significantly longer period of time than the reliabilities of its individual components would suggest. HA, then, is a trade-off between the cost of downtime and the cost of the protective measures that are available to avoid or reduce downtime.
The term High Availability, when applied to computer systems, means that the application or service in question is available all the time, regardless of time of day, location and other factors that can influence the availability of such an application.
In general, HA it is the ability to continue a service for extremely long durations without any interruptions. Hence, HA 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.
HA systems should protect companies from two possible failures: system failures and site failures. Though true HA solutions should guard against both system and site failures, usually HA systems are regarded as protection from system failure, while site failure is typically protected by a Disaster Recovery (DR) system.
Read more »
No comments:
Post a Comment