Question

What is shuffle sharding in AWS

Answer 1

Fault-isolating improvement you can make to traditional horizontal scaling is called sharding. Similar to the technique traditionally used with data storage systems, instead of spreading traffic from all customers across every node, you can group the instances into shards. For example, if you have eight instances for your service, you might create four shards of two instances each (two instances for some redundancy within each shard) and distribute each customer to a specific shard. In this way, you are able to reduce the impact on customers in direct proportion to the number of shards you have. However, there will still be affected customers, so the key is to make the client fault tolerant. If the client can try every endpoint in a set of sharded resources, until one succeeds, you get a dramatic improvement. This technique is called shuffle sharding