No valid host was found. There are not enough hosts available

I am deploying opnFV Euphrates Apex release os-odl-sfc-noha scenario on a CentOS 7 server with 64GB RAM and 56 CPUs.

My deploy-settings.yaml
---
global_params:
  ha_enabled: false

deploy_options:
  sdn_controller: opendaylight
  odl_version: nitrogen
  tacker: false
  congress: true
  sfc: true
  vpn: false

I have used network-settings.yaml as given in /etc/opnfv-apex/network_settings.yaml
After deploying it using

sudo opnfv-deploy -v --debug --virtual-cpus 20 --virtual-default-ram 12 --virtual-compute-ram 40 -n network_settings.yaml -d os-odl-sfc-noha.yaml

After the setup finishes, I add an image in overcloud OpenStack

openstack image create --public --disk-format qcow2 --container-format bare --file /home/heat-admin/xenial-server-cloudimg-amd64-disk1.img ubuntu

But when I launch an instance of m1.medium flavor, 2 instances are launched successfully.
But on creating a 3rd instance I get the following error

Message ---> No valid host was found. There are not enough hosts available.
Code ---> 500
Details ---> File "/usr/lib/python2.7/site-packages/nova/conductor/manager.py", line 868, in schedule_and_build_instances request_specs[0].to_legacy_filter_properties_dict()) File "/usr/lib/python2.7/site-packages/nova/conductor/manager.py", line 599, in _schedule_instances hosts = self.scheduler_client.select_destinations(context, spec_obj) File "/usr/lib/python2.7/site-packages/nova/scheduler/utils.py", line 371, in wrapped return func(*args, **kwargs) File "/usr/lib/python2.7/site-packages/nova/scheduler/client/__init__.py", line 51, in select_destinations return self.queryclient.select_destinations(context, spec_obj) File "/usr/lib/python2.7/site-packages/nova/scheduler/client/__init__.py", line 37, in __run_method return getattr(self.instance, __name)(*args, **kwargs) File "/usr/lib/python2.7/site-packages/nova/scheduler/client/query.py", line 32, in select_destinations return self.scheduler_rpcapi.select_destinations(context, spec_obj) File "/usr/lib/python2.7/site-packages/nova/scheduler/rpcapi.py", line 129, in select_destinations return cctxt.call(ctxt, 'select_destinations', **msg_args) File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py", line 169, in call retry=self.retry) File "/usr/lib/python2.7/site-packages/oslo_messaging/transport.py", line 97, in _send timeout=timeout, retry=retry) File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 578, in send retry=retry) File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 569, in _send raise result

----------------------------------------------------------------------------
I have tried
https://ask.openstack.org/en/question/92701/no-valid-host-was-found-there-are-not-enough-hosts-available/
https://computingforgeeks.com/how-to-fix-openstack-nova-error-novalidhost-no-valid-host-was-found-there-are-not-enough-hosts-available/

but to no avail
----------------------------------------------------------------------------

I am attaching my log file as follows
************************* Nova Compute Node Logs ******************************

nova-conductor.log:3546:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager [req-76b0263c-e693-476d-be2d-b721ba945cb4 1121b6a0480244118e111ba49bca44d6 7905339a70cf47b8bee41f399d703ece - - -] Failed to schedule instances
nova-conductor.log:3547:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager Traceback (most recent call last):
nova-conductor.log:3548:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/conductor/manager.py", line 868, in schedule_and_build_instances
nova-conductor.log:3549:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager request_specs[0].to_legacy_filter_properties_dict())
nova-conductor.log:3550:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/conductor/manager.py", line 599, in _schedule_instances
nova-conductor.log:3551:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager hosts = self.scheduler_client.select_destinations(context, spec_obj)
nova-conductor.log:3552:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/scheduler/utils.py", line 371, in wrapped
nova-conductor.log:3553:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager return func(*args, **kwargs)
nova-conductor.log:3554:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/scheduler/client/__init__.py", line 51, in select_destinations
nova-conductor.log:3555:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager return self.queryclient.select_destinations(context, spec_obj)
nova-conductor.log:3556:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/scheduler/client/__init__.py", line 37, in __run_method
nova-conductor.log:3557:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager return getattr(self.instance, __name)(*args, **kwargs)
nova-conductor.log:3558:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/scheduler/client/query.py", line 32, in select_destinations
nova-conductor.log:3559:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager return self.scheduler_rpcapi.select_destinations(context, spec_obj)
nova-conductor.log:3560:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/scheduler/rpcapi.py", line 129, in select_destinations
nova-conductor.log:3561:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager return cctxt.call(ctxt, 'select_destinations', **msg_args)
nova-conductor.log:3562:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py", line 169, in call
nova-conductor.log:3563:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager retry=self.retry)
nova-conductor.log:3564:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/oslo_messaging/transport.py", line 97, in _send
nova-conductor.log:3565:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager timeout=timeout, retry=retry)
nova-conductor.log:3566:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 578, in send
nova-conductor.log:3567:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager retry=retry)
nova-conductor.log:3568:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 569, in _send
nova-conductor.log:3569:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager raise result
nova-conductor.log:3570:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager NoValidHost_Remote: No valid host was found. There are not enough hosts available.
nova-conductor.log:3571:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager Traceback (most recent call last):
nova-conductor.log:3572:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager
nova-conductor.log:3573:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 218, in inner
nova-conductor.log:3574:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager return func(*args, **kwargs)
nova-conductor.log:3575:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager
nova-conductor.log:3576:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/scheduler/manager.py", line 98, in select_destinations
nova-conductor.log:3577:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager dests = self.driver.select_destinations(ctxt, spec_obj)
nova-conductor.log:3578:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager
nova-conductor.log:3579:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager File "/usr/lib/python2.7/site-packages/nova/scheduler/filter_scheduler.py", line 79, in select_destinations
nova-conductor.log:3580:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager raise exception.NoValidHost(reason=reason)
nova-conductor.log:3581:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager
nova-conductor.log:3582:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager NoValidHost: No valid host was found. There are not enough hosts available.
nova-conductor.log:3583:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager
nova-conductor.log:3584:2018-01-28 16:09:57.338 45643 ERROR nova.conductor.manager

************************* Nova Controller Node Logs ******************************

nova-compute.log:170:2018-01-28 15:15:36.751 43095 ERROR nova.compute.manager [req-8ae9bef9-6f14-4c99-a025-5aed156f6c34 - - - - -] No compute node record for host overcloud-controller-0.opnfvlf.org