AWS Certified Solutions Architect Associate · Free Practice Question Medium
Question 46
An e-commerce application uses a relational database that runs several queries that perform joins on multiple tables. The development team has found that these queries are slow and expensive, therefore these are a good candidate for caching. The application needs to use a caching service that supports multi-threading.
As a solutions architect, which of the following services would you recommend for the given use case?
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A
Amazon ElastiCache for Memcached
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B
Amazon ElastiCache for Redis
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C
AWS Global Accelerator
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D
Amazon DynamoDB Accelerator (DAX)
Reveal correct answer
Correct answer: A
Explanation
Correct option:
Amazon ElastiCache for Memcached
Amazon ElastiCache is a web service that makes it easy to deploy, operate, and scale an in-memory data store and cache in the cloud. The service improves the performance of web applications by allowing you to retrieve information from fast, managed, in-memory data stores, instead of relying entirely on slower disk-based databases.
Memcached is an open-source, distributed, in-memory key-value store that can retrieve data in milliseconds. Caching site information with Memcached can help you improve the performance and scalability of your site while controlling cost.
Choose Memcached if the following apply to you:
You need the simplest model possible.
You need to run large nodes with multiple cores or threads (support for multi-threading).
You need the ability to scale out and in, adding and removing nodes as demand on your system increases and decreases.
You need to cache objects.
Incorrect options:
Amazon ElastiCache for Redis - Redis, which stands for Remote Dictionary Server, is a fast, open-source, in-memory key-value data store for use as a database, cache, message broker, and queue. Redis now delivers sub-millisecond response times enabling millions of requests per second for real-time applications in Gaming, Ad-Tech, Financial Services, Healthcare, and IoT. Redis is a popular choice for caching, session management, gaming, leaderboards, real-time analytics, geospatial, ride-hailing, chat/messaging, media streaming, and pub/sub apps.
Redis does not support multi-threading, so this option is not the right fit for the given use case.
Amazon DynamoDB Accelerator (DAX) - Amazon DynamoDB Accelerator (DAX) is a fully managed, highly available, in-memory cache for Amazon DynamoDB. DAX does not support relational databases.
AWS Global Accelerator - AWS Global Accelerator is a networking service that helps you improve the availability and performance of the applications that you offer to your global users. This option has been added as a distractor, it has nothing to do with database caching.
References:
https://aws.amazon.com/caching/aws-caching/
https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/elasticache-use-cases.html
Discussion
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