Реплики без короны — они в режиме read-only или нет?

Stand-alone replicas without a crown (standalone replicas) are usually in read-only mode, meaning they do not accept write requests. This is because, in a crown architecture (leader/follower), only the crown (leader) handles writes, while replicas synchronize with it to ensure data consistency.

If a crownless replica does not support a consistent update mechanism, writing to it can lead to data inconsistency. Therefore, such replicas are typically used for reading to offload the leader and improve read scalability.

However, the specific behavior depends on the DBMS and cluster settings. In some systems, replicas can be configured for writing, but this requires a complex conflict resolution mechanism.