Yes, you can use a sequentially generated UUID as a primary key. SQL Server even has it built in:
CREATE TABLE dbo.keytest
kt_guid uniqueidentifier NOT NULL
Insert some rows, and SELECT them:
INSERT INTO ...
Galera has the principle that a "quorum" in needed to declare that the cluster is alive.
For example if 'a' disconnects from 'b' and 'c', but 'b' and 'c' are still talking to each other, then
b and c have a quorum (more than half the servers), so they declare they are the cluster.
'a' does not have a quorum, so it refuses to accept any writes.
If the ...