Now a days the globe is getting digital and humans are becoming passionate about technology so it should be available for twenty-four hours and 365 days. to avail the Technology / Service / Infrastructure all the time then it should be highly available. this is where the “High Availability” concepts comes in.
The “High Availability” means Whenever there’s any issue with the Infrastructure, Network, Server, Application or Database Services then how soon you’ll be able to jump back to your feet and restore the services.
Maintaining the high availableness means, having redundancy for your Infrastructure, Network, Server, Application and database at every level by deploying redundant Hardware or setting up the Cluster Services.