I'm going to install Percona XtraDB Cluster, and I have two questions about it:
1- Is it the last step? https://www.percona.com/doc/percona-xtradb-cluster/LATEST/verify.html
Or installing ProxySQL is mandatory? I have only 3 nodes and not planning to add an extra node only for ProxySQL! And I think I don't even need it, my round-robin load-balancer is sending the requests to these servers randomly (without health controlling).
So if a node is down it can't even read/write to the DB. in a nutshell, my application nodes are the same as my DB nodes, and a load-balancer in front of them, So I think I don't need ProxySQL, Am I?
2- What happens if all 3 nodes are down together, I think if this situation happens in a common Group Replication of MySQL, all the cluster collapses and all nodes are being removed from the cluster and we need to reconfigure the cluster manually again, Is the same problem exists in PXC or not?