2 years ago

It’s hard to operate stateful distributed systems at scale, and Redis is no exception. Although I will be citing https://docs.aws.amazon.com/memorydb/latest/devguide/what-is-memorydb-for-redis.html and https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/WhatIs.html for Redis from time to time, most (if not all) will be applicable to Redis clusters in general.

Let’s dive right in and start off with what options you have in terms of scaling your Redis cluster.

Figure 1: Redis (cluster mode disabled) and Redis (cluster mode enabled) clusters – ElastiCache for Redis documentation After scaling your cluster, you better use those replicas! The default behaviour in most Redis Cluster clients (including redis-cli) is to redirect all reads to the primary node.