In version 3.0, the cluster topology is defined in the configuration, so instead of using tt.yaml or running tt replicaset upgrade user:pass@addr:port for each replicaset, the user can simply run tt cluster replicaset upgrade once, and it will upgrade the entire cluster.
In version 3.0, the cluster topology is defined in the configuration, so instead of using tt.yaml or running tt replicaset upgrade user:pass@addr:port for each replicaset, the user can simply run tt cluster replicaset upgrade once, and it will upgrade the entire cluster.