got rid of it…
installed mysql-server community 5.6 (there was no mysql server installed), then created a database oozie, a user oozie and granted all priviledges and access to oozie for oozie user from any machine (and not only localhost)
then run the createdb script as per this doc
http://docs.hortonworks.com/HDPDocuments/Ambari-2.1.0.0/bk_ambari_reference_guide/content/_troubleshooting_oozie.html#_problem_oozie_server_install_fails_using_mysql
my oozie server is started !