Your company has an on-premises, multi-tier PHP web application, which recently experienced
downtime due to a large burst in web traffic due to a company announcement. Over the coming
days, you’re expecting similar announcements to drive similar unpredictable bursts, and are
looking to find ways to quickly improve your infrastructures ability to handle unexpected increases
in traffic. The application currently consists of 2 tiers: A web tier, which consists of a load balancer
and several Linux Apache web servers, as well as a database tier, which hosts a Linux server
hosting a MySQL database.
Which scenario below will provide full site functionality, while helping to improve the availability of
your application in the short timeframe required?
A.
Failover environment:
Create an S3 bucket and configure it for website hosting.
Migrate your DNS to Route53 using zone file import, and leverage Route53 DNS failover to
failover to the S3 hosted website.
B.
Hybrid environment:
Create an AMI, which can be used to launch web servers in EC2.
Create an Auto Scaling group, which uses the AMI to scale the web tier based on incoming traffic.
Leverage Elastic Load Balancing to balance traffic between on-premises web servers and those
hosted In AWS.
C.
Offload traffic from on-premises environment:
Setup a CIoudFront distribution, and configure CloudFront to cache objects from a custom origin.
Choose to customize your object cache behavior, and select a TTL that objects should exist in
cache.
D.
Migrate to AWS:
Use VM Import/Export to quickly convert an on-premises web server to an AMI.
Create an Auto Scaling group, which uses the imported AMI to scale the web tier based on
incoming traffic.
Create an RDS read replica and setup replication between the RDS instance and on-premises
MySQL server to migrate the database.
Explanation:
You can have CloudFront sit in front of your on-prem web environment, via a custom origin (the
origin doesn’t have to be in AWS). This would protect against unexpected bursts in traffic by
letting CloudFront handle the traffic that it can out of cache, thus hopefully removing some of the
load from your on-prem web servers.
D is good but it can not satisfy the requirement of comming days because it is implemented too slowly!
Correct Answer is : A
A: This works if the website is static but we don’t know enough about it to determine if S3 can host it
B: This option is too complicated and I don’t think you can use ELB this way
C: CloudFront works with custom origins, in this case the external PHP web app. CloudFront is a good choice for handling the traffic spike.
D: The scenario does not say the on-prem app is in a VM, this is not an option
Sorry Correct Answer is C.
there is a typo in above post.
C for a quick solution.
In case of a longterm solution, it should be D.