percona-xtradb-cluster-server 5.7.20-29.24-0ubuntu3 (amd64 binary) in ubuntu cosmic

 This is a metapackage package that depends on the current "best" version of
 percona-xtradb-cluster-server, as determined by the Percona XtraDB Cluster
 maintainers. Install this package if in doubt about which version
 you want, as this is the one considered to be in the best shape.