Availability
Ensuring that data and systems are accessible and operational when needed by authorized users
Nines availability
Percentages - 99% is 2 nines, 99.99% is 4 nines
Gold standard of nines
99.999% (5 nines)
Goals of Availability
Business Continuity, Customer Trust, Organization’s Reputation
What is best strategy to achieve availability?
Redundancy
What is redundancy?
Duplication of critical components or functions of a system with the intention of enhancing its reliability
Types of redundancy
Server, Data, Network, Power
Server redundancy
Using multiple servers in a load balance, so that if one is overloaded or fails, the other servers can take over the load to continue supporting end users
Data redundancy
Storing data in multiple places
Network redundancy
If one network path fails, the data can travel through alternate route
Power redundancy
Using backup power sources to ensure power supply during periods of power disruption or outages in local service area
What word is Availability linked with?
Redundancy
