ElastiCache is not entirely free, but there is a free tier available for new customers to use for the first 12 months. The free tier includes up to 750 hours per month of a cache.t2.micro node running Redis or Memcached, along with 250 MB of cache capacity.
After the free tier period expires or if you exceed the limits of the free tier, you will be charged based on the type and number of nodes you use, as well as the amount of data stored in your cache. You can view the current pricing for ElastiCache on the AWS website.
Here's an example of how to create a Redis cache cluster using the AWS CLI:
aws elasticache create-cache-cluster \ --cache-cluster-id my-redis-cluster \ --engine redis \ --cache-node-type cache.t2.micro \ --num-cache-nodes 1 \ --preferred-availability-zone us-west-2a
This command creates a single node Redis cluster using a cache.t2.micro instance type in the US West (Oregon) region. You can modify the parameters to fit your specific use case.
Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement.