Comment 7 for bug 1570936

I checked the Oleksiy's environment and see the following:

- right after reverting a snapshot nova-cert service is marked as down

- nova-cert process is up and running

- there are no open connections to mysqld - http://paste.openstack.org/show/494792/ - NOTE: there is one broken socket (can't identify protocol)

- service logs contain no errors: http://paste.openstack.org/show/494794/

- when I tried to attach to the process with strace, it figured out that connection to mysqld (haproxy in our case) is broken, then closed and re-opened it properly - http://paste.openstack.org/show/494795/

- all services are up now - http://paste.openstack.org/show/494796/

NOTE: no service restarts were performed

My current understanding is that destroying of a VIP produces a dead TCP peer - nova-cert simply does not know it should close the existing connection and open a new one. Maybe we should take a look at TCP keepalives? (http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/overview.html)