Replication

When working with distributed systems you can encounter terminology such as “replicas” or “standby” intstances. When I first started learning about distrubuted systems, I assumed “replicas” and “standby” were the same thing, but called differently when talking about scaling or high availability. While they can be the same thing, that is not always the case, so I wanted to clarify the concepts in this post. Replicas Replicas are one or more exact copies of the primary instance of your database. Their main purpose is to balance the load. ...

Replication refers to having copies of your data across different instances. It gives you redundancy when one of your instances goes down so you can still serve data to users from the remaining instances. Another benefit of a replicated system is being able to load balance your requests across different instances. This can be useful when the load of serving all the requests from a single instance would be too much. ...