DOP-C01 Exam QuestionsBrowse all questions from this exam
Go to Exam

DOP-C01 Exam - Question 164

A company has an application that monitors user activity on the company's website and mobile apps. The application uses Amazon ElastiCache for Redis as a write-through cache and uses an Amazon RDS for PostgreSQL database for longer storage. When the application receives a request to record a user's action, the application writes to the Redis cluster and the database at the same time. Internal recommendation applications consume the data to produce content recommendations for each user.

During peak periods, the recommendation applications cannot generate recommendations for users because of stale and missing data. The Redis cache is configured with cluster mode turned off, and the database is configured with a single read replica.

The company wants to ensure that the recommendation applications can generate content recommendations during peak periods. A DevOps engineer already has created a new ElastiCache for Redis cluster with cluster mode enabled.

What should the DevOps engineer do next to meet the company's requirements?

Show Answer
Correct Answer: A

The best course of action is to create a target tracking auto scaling policy for the Redis cluster's ElastiCachePrimaryEngineCPUUtilization metric. This will allow the system to automatically adjust the number of shards in the Redis cluster based on CPU usage, ensuring that the workload is handled efficiently during peak periods. Additionally, updating the recommendation applications to use the cluster's configuration endpoint will enable them to interact with the Redis cluster properly when cluster mode is enabled. This setup allows dynamic scaling and efficient data handling for generating content recommendations.

Discussion

14 comments
Sign in to comment
DimidrolOption: B
Jan 17, 2023

I think between A and B. Choose B because no need to write.https://aws.amazon.com/ru/about-aws/whats-new/2019/06/amazon-elasticache-launches-reader-endpoint-for-redis/

Christina666Option: B
Jan 21, 2023

read replicas endpoint for traffic

saeidpOption: A
Jan 22, 2023

A for me cluster mode is enabled. https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Endpoints.html answere B is good for cluster mode disabled

saeidp
Jan 29, 2023

By the way cluster mode disabled only uses one shard

BultiOption: A
Jan 28, 2023

A is the right answer. use Cluster configuration endpoint and when target tracking scaling policy is used with a predefined metric of ElastiCachePrimaryEngineCPUUtilization it scale out the shards and not the replicas.

zekOption: B
Jan 29, 2023

I think the answer is B from link: https://aws.amazon.com/ru/about-aws/whats-new/2019/06/amazon-elasticache-launches-reader-endpoint-for-redis/. "You can now use a single reader endpoint to connect to your Redis read replicas"

USalo
Jan 30, 2023

In the same link: "Reader endpoints work with ElastiCache for Redis clusters with cluster-mode disabled." But it the question it was clearly mentioned that new Redis cluster was created with cluster mode ENABLED. Also please read another URL: https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Endpoints.html Redis (cluster mode disabled) clusters, use the Primary Endpoint for all write operations. Use the Reader Endpoint to evenly split incoming connections to the endpoint between all read replicas. Redis (cluster mode enabled) clusters, use the cluster's Configuration Endpoint for all operations that support cluster mode enabled commands. The answer should be "A"

dailydoseofDevops
Dec 1, 2023

Cluster mode is turned off thus disabled, as a result the Read Replica Endpoint is correct. Standalone Node o One endpoint for read and write operations. Cluster Mode Disabled Cluster o Primary Endpoint – for all write operations. o Reader Endpoint – Split read operations across all read replicas evenly. o Node Endpoint – for read operations. Cluster Mode Enabled Cluster o Configuration Endpoint –for all read/write operations that support Cluster Mode Enabled commands. (way to connect to cluster) o Node Endpoint –for read operations.

DerekKeyOption: D
Feb 4, 2023

A & B - wrong - cluster mode is turned-off - it means that there is only one shard (one primary and up to 5 secondary nodes), it can not be changed - you can not increase/decrease shards C - wrong - configuration endpoint is for cluster enabled Redis D - correct - the recommendation app should use read replica endpoint

USalo
Feb 6, 2023

regarding cluster mode, ready attentively: A DevOps engineer already has created a new ElastiCache for Redis cluster with cluster mode enabled.

devops7Option: A
Jan 19, 2023

I agree the answer is either A or B but I don't see "cluster's read replica" in the question. So, I select A

PiccasoOption: A
Feb 13, 2023

https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Endpoints.html

LoveTorontoOption: A
Feb 18, 2023

https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Endpoints.html

bgc1Option: A
Mar 5, 2023

Its A based on this - https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Endpoints.html Redis (cluster mode enabled) clusters, use the cluster's Configuration Endpoint for all operations that support cluster mode enabled commands.

PiccasoOption: B
Feb 19, 2023

No idea why D is suggested by this web. Are the peak periods come regularly every day ?

harrura
Mar 5, 2023

what is this crap? robot answers are different from the user poll. this sucks. what is the correct answer damn it!!

Dgix
Oct 20, 2023

A. Redis clusters do not support read replicas, which are mentioned in all other options.

auxwww
Jul 10, 2024

A - ElastiCache cluster with configuration endpoint ensures writes go to the primary and reads go to the replica shards. The cache needs to be written to as well, and read too