Restarting a cluster

In a multi-master replication cluster, a reference point must be established before other nodes can join and form the cluster. This is called cluster bootstrapping and involves starting a single node as the primary component. Restarting a single node or reconnecting after a shutdown can be done normally.

In case of a full cluster shutdown, the server that was stopped last should be started first with the --new-cluster command line option or by running manticore_new_cluster through systemd. To ensure that the server is capable of being the reference point, the grastate.dat file located at the cluster path should be updated with a value of 1 for the safe_to_bootstrap option. Both conditions, --new-cluster and safe_to_bootstrap=1, must be met. If any other node is started without these options set, an error will occur. The --new-cluster-force command line option can be used to override this protection and start the cluster from another server forcibly. Alternatively, you can run manticore_new_cluster --force to use systemd.

In the event of a hard crash or an unclean shutdown of all servers in the cluster, the most advanced node with the largest seqno in the grastate.dat file located at the cluster path must be identified and started with the --new-cluster-force command line key.