closing this as a duplicate of https://bugzilla.redhat.com/show_bug.cgi?id=1955031 this is not really a nova bug but a misconfiguration of the neutorn timeouts too compenstate for the excessive slowness of the neutron api responces. the workaround is to increase the neutron client timeouts both on nova and neutron wsgi server but also in haproxy to allow nova to wiat for the eventual response form neutron. *** This bug has been marked as a duplicate of bug 1955031 ***