CloudFront & ElastiCache for Redis
The example shows the whole environment perhaps build by CloudFormation. Video data comes in by CloudFront from Video encoders and maybe the requested input is in CloudFront, it’s send back directly.
If not it’s stored in S3, a Lambda function updates some metadata and it’s stored in Dynamo DB. The second event is triggered to an SNS topic to the required Lambda function for reformatting and resizing and the result is stored in an other S3 bucket, called Playback. And CloudFrontStreaming is pushing it right back to my consumers. ElastiCache for Redis helps the Client to search in a created DynamoDB index.
Amazon Elasti Cache is an other form of caching. It’s the idea of caching elastic inside the stack by using open-souce infrastructure elements: Redis and Memcached. Useful if the query of the database is expensive, you could store temporary stage it in memory in the elastic cache.