Web App: High Availability / How to prevent a single point of failure?
Can someone explain to me how high-availability ("HA") works for a web application ... because I assume HA means that there exist no single-point-of-failure.
However, even if a load balancer is used- isn't that the single point of failure?
Solution 1:
I have found this article on the subject: http://www.tenereillo.com/GSLBPageOfShame.htm
Basically if you do not require long lasting sticky sessions you can configure your DNS servers to return multiple A records (IP addresses) for your website.
Web browsers are smart enough to try all the addresses until they find one that works.
Solution 2:
In simple words high availability can be defined as running a system 24*7 without a downtime even if there are hardware and software failures. In other way a fault tolerance application. This helps ensure uninterrupted use of the application for it’s intended users.
Read more on High Availability Deployment Architecture