Hello list I have to upgrade a cluster and I hoped I can do it safely without a downtime. In my understanding though it is not possible. In my specific case, the cluster is 10.0 and must be upgraded to 10.1. There is a "master" node. Steps are: 1. I upgrade all "slave" nodes 2. I change the "master" 3. I upgrade the old master The problem is that, between 2 and 3, old master is 10.0, and it replicates from 10.1. This is not supported, based on this page: https://mariadb.com/kb/en/mariadb/upgrading-mariadb-upgrading-from-mariadb-g... "to prevent 10.1 propagating to 10.0, which is not supported" So my question is, is there a way to upgrade this cluster without writes downtime? Regards, Federico