Dax

• DAX is an in memory cache
• DAX works from inside a VPC unlike DynamoDB which is a public service
• It needs to be deployed into multiple AZs within the VPC for high availability
• DAX has 2 caches
• An Item cache of Items that were directly retrieved by GetItem calls
• A Query cache the stores both the query results as well as query parameters
• Cache hits respond in microseconds wile misses respond in milliseconds
• DAX uses Write Thruogh cache
• DAX's primary node supports read operation while Replicas are for Reads
• DAX is not good solution for applications that need strong consistency