In a causal cluster, there can be two categories of servers. Core servers are the most important over read replica servers, as replicas are disposable and can be either added or removed during the scaling of the cluster. Let's go through their roles.
Concepts
Core servers
Core servers are the most important servers of a cluster. The minimum number of core servers in a cluster is three for a transaction is reported as successful to the user who started it when the update generated is propagated to half the size of the cluster plus 1.
The roles of core servers are as follows:
- They are the targets of all the updating queries; they uphold data consistency via the consensus commit
- They are responsible for data safety
- They...