A 3-Ber e-commerce web application is currently deployed on-premises, and will be migrated to
AWS for greater scalability and elasticity. The web tier currently shares read-only data using a
network distributed file system. The app server tier uses a clustering mechanism for discovery
and shared session state that depends on IP multicast. The database tier uses shared-storage
clustering to provide database failover capability, and uses several read slaves for scaling. Data
on all servers and the distributed file system directory is backed up weekly to off-site tapes.
Which AWS storage and database architecture meets the requirements of the application?
A.
Web servers: store read-only data in S3, and copy from S3 to root volume at boot time.
App servers: share state using a combination of DynamoDB and IP unicast.
Database: use RDS with multi-AZ deployment and one or more read replicas.
Backup: web servers, app servers, and database backed up weekly to Glacier using snapshots.
B.
Web servers: store read-only data in an EC2 NFS server, mount to each web server at boot time.
App servers: share state using a combination of DynamoDB and IP multicast.
Database: use RDS with multi- AZ deployment and one or more Read Replicas.
Backup: web and app servers backed up weekly via AMIs, database backed up via DB
snapshots.
C.
Web servers: store read-only data in S3, and copy from S3 to root volume at boot time.
App servers:
share state using a combination of DynamoDB and IP unicast.
Database: use RDS with multi-AZ deployment and one or more Read Replicas.
Backup: web and app servers backed up weekly via AMIs, database backed up via DB
snapshots.
D.
Web servers: store read-only data in S3, and copy from S3 to root volume at boot time.
App servers:
share state using a combination of DynamoDB and IP unicast.
Database: use RDS with multi-AZ deployment.
Backup: web and app servers backed up weekly via AMIs, database backed up via DB
snapshots.
Explanation:
https://d0.awsstatic.com/whitepapers/Storage/AWS%20Storage%20Services%20Whitepaperv9.pdf
Amazon Glacier doesn’t suit all storage situations. Listed following are a few
storage needs for which you should consider other AWS storage options instead
of Amazon Glacier.
Data that must be updated very frequently might be better served by a storage solution with lower
read/write latencies, such as Amazon EBS, Amazon RDS, Amazon DynamoDB, or relational
databases running on EC2.
C
Snapshots in glacier does not work
Answer is A because in the offshore setup backup is going to tape library and when you architecting the same glacier should be considered as the archival option.
If you use EBS&RDS snapshot feature, they can’t be stored in Glacier, this rule answer A.
B is wrong because multicast is not available in AWS.
D is wrong because the lack of Read Replica doesn’t scale.
Correct answer is C
A: can’t directly backup EBS snapshots to Glacier.
B: AWS does not support IP Multicast.
D: misses DB read replicas
Thus, C is the right answer.