auto-mux: Trying existing master

I met a issue when run a playbook. what caused that symtom ?

[root@director restart-service-overcloud]# vim site.yml
[root@director restart-service-overcloud]# ansible-playbook site.yml

PLAY [controllers] ************************************************************

GATHERING FACTS ***************************************************************
ok: [slot7]
ok: [slot14]
ok: [slot5]

TASK: [controller | script restart-service.sh neutron-l3-agent] **************
changed: [slot14]
failed: [slot5] => {“changed”: true, “rc”: 1}
stderr: OpenSSH_6.6.1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 56: Applying options for *
debug1: auto-mux: Trying existing master
debug1: mux_client_request_session: master session id: 2
Shared connection to slot5 closed.

stdout: Error: Unable to cleanup resource: neutron-l3-agent
Error performing operation: No such device

failed: [slot7] => {“changed”: true, “rc”: 1}
stderr: OpenSSH_6.6.1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 56: Applying options for *
debug1: auto-mux: Trying existing master
debug1: mux_client_request_session: master session id: 2
Shared connection to slot7 closed.

stdout: Error: Unable to cleanup resource: neutron-l3-agent
Error performing operation: No such device

TASK: [controller | script restart-service.sh neutron-metadata-agent] ********
changed: [slot14]

TASK: [controller | script restart-service.sh neutron-dhcp-agent] ************
changed: [slot14]

TASK: [controller | script restart-service.sh neutron-openvswitch-agent] *****
changed: [slot14]

TASK: [controller | script restart-service.sh neutron-server] ****************
changed: [slot14]

TASK: [controller | script restart-service.sh openstack-nova-scheduler] ******
changed: [slot14]

TASK: [controller | script restart-service.sh openstack-nova-conductor] ******
changed: [slot14]

TASK: [controller | script restart-service.sh openstack-nova-api] ************
changed: [slot14]

PLAY [computes] ***************************************************************

GATHERING FACTS ***************************************************************
ok: [slot2]
ok: [slot9]
ok: [slot4]
ok: [slot1]
ok: [slot3]
ok: [slot13]
ok: [slot10]
ok: [slot11]
ok: [slot12]

TASK: [compute | shell openstack-service restart] *****************************
changed: [slot3]
changed: [slot4]
changed: [slot9]
changed: [slot1]
changed: [slot2]
changed: [slot11]
changed: [slot13]
changed: [slot10]
changed: [slot12]

TASK: [compute | neutron-sriov-nic-agent.service] *****************************
changed: [slot2]
changed: [slot4]
changed: [slot1]
changed: [slot3]
changed: [slot9]
changed: [slot10]
failed: [slot13] => {“failed”: true}
msg: failure 1 running systemctl show for ‘neutron-sriov-nic-agent.service’: Unit neutron-sriov-nic-agent.service could not be found.

changed: [slot11]
changed: [slot12]

PLAY RECAP ********************************************************************
to retry, use: --limit @/root/site.retry

slot1 : ok=3 changed=2 unreachable=0 failed=0
slot10 : ok=3 changed=2 unreachable=0 failed=0
slot11 : ok=3 changed=2 unreachable=0 failed=0
slot12 : ok=3 changed=2 unreachable=0 failed=0
slot13 : ok=2 changed=1 unreachable=0 failed=1
slot14 : ok=9 changed=8 unreachable=0 failed=0
slot2 : ok=3 changed=2 unreachable=0 failed=0
slot3 : ok=3 changed=2 unreachable=0 failed=0
slot4 : ok=3 changed=2 unreachable=0 failed=0
slot5 : ok=1 changed=0 unreachable=0 failed=1
slot7 : ok=1 changed=0 unreachable=0 failed=1
slot9 : ok=3 changed=2 unreachable=0 failed=0

[root@director restart-service-overcloud]#