Designing systems for High Availability

What Is High Availability?

Highly available(HA) systems are reliable in the way that they continue business operations even when critical components fail. They are also resilient, which means that they are able to easily handle failure without services disruption or any type of data loss, and easily recover from such failure.

High availability is usually measured as a percentage of uptime. The number of “nines” is commonly used to indicate the degree of high availability. A system that is up 99.99% of the time, means it is down for only 52.6 minutes during an entire year.

Let's talk about a few of the best practices we can use to design our systems for high availability.