Examkin

Question

Difficulty: HardHigh Availability, Scalability, and Elasticity

An application that automatically scales out by adding virtual machine instances during peak traffic and scales in when demand subsides is demonstrating elasticity; however, this design does not guarantee high availability if all instances are deployed within a single availability zone.

Answer: Answer

Answer

The statement is true because automatic scaling (elasticity) does not provide resilience against physical datacenter or availability zone failures (high availability) unless the instances are distributed across multiple zones or regions.
The correct evaluation is true because automatic resource adjustment (elasticity) does not protect an application from physical zone-wide failures unless it is also designed with physical redundancy across multiple availability zones.

Step-by-Step Solution

1
Analyze the definition and behavior of elasticity.
Scaling out (adding instances) and scaling in (removing instances) automatically based on traffic demand is the definition of elasticity.
To verify if the first part of the statement correctly identifies elasticity.
2
Analyze the requirements of high availability and the impact of a single availability zone deployment.
If all instances reside in a single zone, a zone-wide outage will take down all instances. High availability requires physical redundancy across failure domains.
To verify if the second part of the statement correctly identifies that elasticity within a single zone does not guarantee high availability.
3
Evaluate the correctness of the combined statement.
Both parts of the statement are correct; thus, the overall statement is true.
To determine the final true/false value.

Key Concept

The difference between elasticity and high availability, and the role of availability zones in providing physical redundancy.
Rate this question

Topics

High Availability, Scalability, and Elasticity

More questions from this topic