Question: When to use ElastiCache vs DynamoDB?

Answer

Amazon Elasticache and Amazon DynamoDB are two of the most popular managed services offered by AWS. Both services are designed to improve application performance, but they have different use cases.

Amazon Elasticache

Amazon ElastiCache is a fully-managed, in-memory cache service that supports two open-source in-memory caching engines: Redis and Memcached. It provides a fast and scalable way to improve the performance of web applications by caching frequently accessed data in memory.

ElastiCache is best suited for read-heavy workloads, such as social media platforms, e-commerce websites, and gaming applications. It can help reduce latency and improve throughput by reducing the number of requests made to a database or backend service.

Here are some use cases where ElastiCache would be a good fit:

1. Caching frequently accessed data to improve application performance.
2. Scaling horizontally to handle large amounts of traffic.
3. Reducing the load on a backend database.
4. Storing session data for stateless applications.

Amazon DynamoDB

Amazon DynamoDB is a fully-managed NoSQL database service that provides fast and predictable performance with seamless scalability. It's designed to handle any type of data and can scale from a few requests per second to millions of requests per second.

DynamoDB is best suited for both read and write-heavy workloads, such as mobile applications, ad tech platforms, and IoT devices. It provides a flexible data model and allows you to store and query semi-structured data at scale.

Here are some use cases where DynamoDB would be a good fit:

1. Storing and querying large amounts of semi-structured data.
2. Handling high write and read workloads.
3. Building real-time applications that require low-latency access to data.
4. Supporting use cases that require frequent schema changes.

In summary, you should use Amazon ElastiCache when you need to cache frequently accessed data and improve application performance. You should use Amazon DynamoDB when you need to store and query semi-structured data at scale or have to handle high write and read workloads.