Question 1

What's the difference between In-Memory Caching and a CDN?

Accepted Answer

In-memory caching stores application data in RAM close to your app (for example, product details, user sessions, query results). A CDN caches static or cacheable content (like images, CSS, JavaScript, and sometimes full pages) at edge locations near users. Use in-memory caching to reduce database and service calls; use a CDN to reduce latency and bandwidth for content delivery.

Question 2

When should I use In-Memory Caching?

Accepted Answer

Use it when you have read-heavy workloads, repeated queries for the same data, expensive computations, or high database load. Common fits include product catalogs, user profiles, session storage, rate limiting, feature flags, and caching API responses. It’s especially useful when you can tolerate slightly stale data (seconds to minutes) or can invalidate cache entries when updates occur.

Question 3

How much does In-Memory Caching cost?

Accepted Answer

Cost depends mainly on (1) cache engine (Redis vs Memcached), (2) node size and count (RAM/CPU), (3) high availability setup (replicas, multi-AZ), (4) network data transfer, and (5) optional features like persistence, backups, and encryption. Managed services typically charge per cache node-hour plus storage for backups (if used) and data transfer in some cases. Larger RAM footprints and replicas increase cost most.

In-Memory Caching

Definition

Real-World Example

Related Terms

Cloud Provider Equivalencies

Compare Across Cloud Providers

Explore More Cloud Computing Terms