Your company currently has a 2-tier web application running in an on-premises data center. You have
experienced several infrastructure failures in the past two months resulting in significant financial losses. Your
CIO is strongly agreeing to move the application to AWS. While working on achieving buy-in from the other
company executives, he asks you to develop a disaster recovery plan to help improve Business continuity in
the short term. He specifies a target Recovery Time Objective (RTO) of 4 hours and a Recovery Point Objective
(RPO) of 1 hour or less. He also asks you to implement the solution within 2 weeks. Your database is 200GB in
size and you have a 20Mbps Internet connection. How would you do this while minimizing costs?
A.
Create an EBS backed private AMI which includes a fresh install or your application. Setup a script in your
data center to backup the local database every 1 hour and to encrypt and copy the resulting file to an S3
bucket using multi-part upload.
B.
Install your application on a compute-optimized EC2 instance capable of supporting the application’s
average load synchronously replicate transactions from your on-premises database to a database instance in
AWS across a secure Direct Connect connection.
C.
Deploy your application on EC2 instances within an Auto Scaling group across multiple availability zones
asynchronously replicate transactions from your on-premises database to a database instance in AWS across a
secure VPN connection.
D.
Create an EBS backed private AMI that includes a fresh install of your application. Develop a Cloud
Formation template which includes your Mil and the required EC2. Auto-Scaling and ELB resources to support
deploying the application across Multiple-Ability Zones. Asynchronously replicate transactions from your onpremises database to a database instance in AWS across a secure VPN connection.
D.
A – backing up local DB of 200GB on a 20Mbps connection every hour doesn’t seem like the best option.
B,C – EC2 instances dont need to be up. Only DB transactions need to be replicated to a DB on AWS.
For A, the backup can be incremental
But S3 is still more expensive than EBS
How do you figure that? Right now EBS 10 cents per GB storage for general purpose block storage. S3 is 2.3 cents per GB for standard storage.
answer is D pilot mode
Question is how will you minimize the cost ?.. Does option D will minimize the cost ?
Seems to be A..
D is the answer.
A would not solve the problem BUT potentially make the issue more severe. Because “… backup the local database every 1 hour …” would reduce the performance of local DB even lower.
I’m tempted to consider B as the answer. The synchronous replication of data convinces me it will be the only situation where the data is in sync to allow DR to take place
B is the most expensive way to deal with problem.
B is definetly not good – Direct Connect is never established within the given timeframe of 2 weeks.
D is the right answer.
A is wrong because backing up local DB of 200GB on a 20Mbps connection every hour is not reliable and consumes a lot of bandwidth (expensive).
B and C are wrong as you don’t need EC2 instances to be up and running because it is expensive. You rather need to be able to quickly launch them within RTO of 4 hours.
D is right answer
A: S3 object based and incremental – not cost efficient
B: Direct Connect is very expensive
C: you don’t need your EC2 instance up and running
While I appreciate your answer. For B, Direct connect being expensive is not a consideration because VPN in option D will also make use of a Direct Connect solution.
And I think using multipart upload solves the problem of 20MBps connection. So, I will like to choose A.
But popular opinion chooses D, can someone please explain to me how D. meets the requirement of Recovery Time Objective (RTO) of 4 hours and a Recovery Point Objective(RPO) of 1 hour or less.
A lot of these questions seem to be related to the SA exam, and not the SAA exam? The first 150 questions seem like they are easier and shorter questions that you might see on the SAA exam? Just trying to figure out if I need to study these questions for the SAA exam.
I’m wondering same thing.
D says multiple-ability zone which is incorrect
Thus A is the only right answer
D would be expensive, I will go with A.
Apologies guys, Answer is D.
Explanation: Overview of Creating Amazon EBS-Backed AMIsFirst, launch an instance
from an AMI that’s similar to the AMI that you’d like to create. You can connect to your
instance and customize it. When the instance is configured correctly, ensure data integrity
by stopping the instance before you create an AMI, then create the image. When you
create an Amazon EBS-backed AMI, we automatically register it for you.
Amazon EC2 powers down the instance before creating the AMI to ensure that everything
on the instance is stopped and in a consistent state during the creation process. If you’re
confident that your instance is in a consistent state appropriate for AMI creation, you can
tell Amazon EC2 not to power down and reboot the instance. Some file systems, such as
XFS, can freeze and unfreeze activity, making it safe to create the image without rebooting
the instance.
During the AMI-creation process, Amazon EC2 creates snapshots of your instance’s root
volume and any other EBS volumes attached to your instance. If any volumes attached to
the instance are encrypted, the new AMI only launches successfully on instances that
support Amazon EBS encryption. For more information, see Amazon EBS Encryption.
Depending on the size of the volumes, it can take several minutes for the AMI-creation
process to complete (sometimes up to 24 hours).You may find it more efficient to create
snapshots of your volumes prior to creating your AMI. This way, only small, incremental
snapshots need to be created when the AMI is created, and the process completes more
quickly (the total time for snapshot creation remains the same). For more information, see
Creating an Amazon EBS Snapshot.
After the process completes, you have a new AMI and snapshot created from the root
volume of the instance. When you launch an instance using the new AMI, we create a new
EBS volume for its root volume using the snapshot. Both the AMI and the snapshot incur
Leaders in it certification (D4D.us) 32
charges to your account until you delete them. For more information, see Deregistering
Your AMI.
If you add instance-store volumes or EBS volumes to your instance in addition to the root
device volume, the block device mapping for the new AMI contains information for these
volumes, and the block device mappings for instances that you launch from the new AMI
automatically contain information for these volumes. The instance-store volumes specified
in the block device mapping for the new instance are new and don’t contain any data from
the instance store volumes of the instance you used to create the AMI. The data on EBS
volumes persists. For more information, see Block Device Mapping.
I think that D is correct
I think D is the correct one.
B is the most expensive and it use Direct Connect which is not ideal for 2 weeks solution.
C is wrong because we don’t need running EC2 instance
A and D are both visible but A is not as good as D because 1. upload 200GB over 20Mbps take a day, only visible way is to using incremental backup 2. Recover from incremental backup take times and might not satisfy RTO