AWS Caching Best Practices | Highly Available Application Caching

AWS Caching Best Practices

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Question

Your company needs to develop an application that needs to have a caching feature.

The application cannot afford many cache failures and should be highly available.

Which of the following would you choose for this purpose?

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D.

Answer - C.

Cluster Mode comes with the primary benefit of horizontal scaling up and down of your Redis cluster, with almost zero impact on the performance of the cluster, as I will demonstrate later.

ElastiCache for Redis with Cluster Mode Enabled works by spreading the cache key space across multiple shards.

This means that your data and read/write access to that data is spread across multiple Redis nodes.

By spreading the load over a greater number of nodes, we can both enhance availability and reduce bottlenecks during periods of peak demand, while providing more memory space than a single node could offer.

Options A and D are incorrect since using a single EC2 Instance would be a single point of failure, not suitable for high availability.

Option B is incorrect since Redis would be better for high availability.

For more information on Redis ElastiCache, please refer to the below URL-

https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/WhatIs.html https://aws.amazon.com/blogs/database/work-with-cluster-mode-on-amazon-elasticache-for-redis/ https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Replication.Redis-RedisCluster.html

For an application that requires caching with high availability and minimal cache failures, using Amazon ElastiCache would be the best option. ElastiCache is a fully managed, in-memory data store and caching service that supports two popular open-source in-memory caching engines, Redis and Memcached.

Option A suggests using Memcached on an EC2 instance, which means setting up and managing a standalone cache node on an EC2 instance. While this option may work, it requires more effort in terms of maintenance, monitoring, and scaling, and is therefore not an ideal solution for an application that needs high availability and minimal cache failures.

Option B suggests using ElastiCache with Memcached. This option is a better choice than using Memcached on an EC2 instance because it provides a fully managed caching solution with high availability, scalability, and fault tolerance. ElastiCache manages the Memcached nodes for you and provides automatic failover, backup and restore, and monitoring.

Option C suggests using ElastiCache with Redis in Cluster-Mode Enabled. Redis is an in-memory data store that supports key-value, document, graph, and other data structures. Cluster mode enables Redis to distribute data across multiple nodes in a cluster, providing better scalability and fault tolerance than standalone Redis nodes. Using ElastiCache with Redis in Cluster-Mode enabled provides a highly available and scalable caching solution.

Option D suggests using Redis on an EC2 instance, which is similar to option A but with Redis instead of Memcached. While Redis can be a good choice for caching, using it on an EC2 instance means managing the Redis nodes yourself, which requires more effort and can lead to higher cache failures and lower availability than using a fully managed caching service like ElastiCache.

Therefore, the best option for an application that needs caching with high availability and minimal cache failures is to use ElastiCache with either Memcached or Redis in Cluster-Mode enabled, depending on the specific requirements of the application.