How well does Percona XtraDB Cluster support UUIDs for primary keys?
PXC does no change to the way MySQL generates UUIDs, and from the general concept, a UUID should be 100% unique between the nodes, as part of if is based on hardware uniqueness, like the eth card MAC.
See here for more details:
[url]https://www.percona.com/blog/2014/12/19/store-uuid-optimized-way/[/url]
[url]MySQL :: MySQL 5.6 Reference Manual :: 12.20 Miscellaneous Functions