Set up a three-node cluster on a single box

Hi,
I’m newbie ,
I follow [URL=“https://www.percona.com/doc/percona-xtradb-cluster/5.7/howtos/singlebox.html”]https://www.percona.com/doc/percona-...singlebox.html[/URL]
but when

$ bin/mysqld_safe --defaults-file=/etc/my.4000.cnf --wsrep-new-cluster

Output

sudo bin/mysqld_safe --defaults-file=/etc/my.4000.cnf --wsrep-new-cluster 2017-05-08T10:14:35.554354Z mysqld_safe Logging to '/data/bench/d1/error.log'.
2017-05-08T10:14:35.557527Z mysqld_safe Logging to '/data/bench/d1/error.log'.
2017-05-08T10:14:35.596555Z mysqld_safe Starting mysqld daemon with databases from /data/bench/d1
2017-05-08T10:14:35.602722Z mysqld_safe Skipping wsrep-recover for empty datadir: /data/bench/d1
2017-05-08T10:14:35.604886Z mysqld_safe Assigning 00000000-0000-0000-0000-000000000000:-1 to wsrep_start_position
2017-05-08T10:14:35.888999Z mysqld_safe mysqld from pid file /data/bench/d1/hytekvn.com.vn.pid ended

how can I fix it?
Thanks