My specific questions are :
1) How would you architect a three-tiered web application to limit downtime?
2) How to eliminate point of failures from a 3 tiered architecture
I could not find any resources that specifically answer these questions. I would like to the opinion of the community
Regardless of which architecture you choose failure could happen and would happen. the real question isn't elimination of fault but reducing.
In 3 tier you may have ui, business layer and db access layer. any of these is single point of failure. so one goes down whole app stops working.
You have to rely on redundancy. You may need to deploy mutiple copies of each tier. the more copies you deploy the more fault tolerant it is. generally each tier talks to load balancer to talk to down stream services. and load balancer will be balancing multiple copies on each tier.
