Redundancy & High Availability FAQs

Question 1

Why is 'redundancy theater' a problem?

Accepted Answer

Redundancy theater occurs when backup systems are built but never tested. Without regular failover drills and monitoring, backup systems may fail silently, leaving the system vulnerable when a real outage occurs.

Question 2

What is the difference between Active-Active and Active-Passive redundancy?

Accepted Answer

In Active-Active, all redundant components handle load simultaneously, providing zero-downtime failover. In Active-Passive, a backup system stays idle and only takes over when the primary system fails.

Question 3

What are correlated failures in system design?

Accepted Answer

Correlated failures occur when redundant components share a hidden dependency, such as the same power source or network switch, causing both the primary and backup to fail at the same time.

Question 4

What is the primary goal of the Redundancy skill?

Accepted Answer

The primary goal is to help developers and architects design systems where the failure of a single component doesn't lead to a total system collapse, ensuring high availability and reliability.

Question 5

How does redundancy impact system costs?

Accepted Answer

Redundancy typically increases costs because it requires extra hardware or cloud resources. It is an economic trade-off where the cost of the backup is balanced against the potential financial loss of downtime.

Redundancy & High Availability

Key Features

Use Cases

Redundancy & High Availability

Key Features

Use Cases