Memory access amortization #
Random memory access is an expensive operation. AWS introduced memory access amortization(MAA), a technique to reduce memory access costs, especially for big dynamic data structures such as those used in redis.
MAA interleaves the steps from many data structure operations to ensure parallel memory access and reduces memory access latency. In Elasticache for Redis 7.1 AWS applied this method on the redis dictionary, and we get up to 60% reduction in hash-find, and accelerated commands.
This is depicted in the following example, where the main Redis processing thread receives three parsed commands from the enhanced I/O threads. Next, it interleaves a dictionary-find procedure to simultaneously prefetch needed data into the CPU cache.
