Description of problem:
openstack baremetal import --json instackenv.json fails when the imported nodes are powered on. The instackenv.json contains 15 nodes(VMs).

This is blocking automation for the composable roles testing.

Version-Release number of selected component (if applicable):
python-tripleoclient-5.2.1-0.1.34590ccgit.el7.noarch

How reproducible:
100%

Steps to Reproduce:
1. Build instackenv.json with 15 nodes which are powered on
2. openstack baremetal import --json instackenv.json

Actual results:
Import fails:

stdout: Started Mistral Workflow. Execution ID: 8a1a9930-1b53-4ce2-9a2f-c0c29eae406f

stderr: Exception registering nodes: [{u'__task_execution': {u'id': u'88fd8862-ab81-4291-b20e-aa82957508bf', u'name': u'wait_for_provision_state'}}, {u'__task_execution': {u'id': u'684d1464-7fa0-4c3b-aeac-dce73b7fd07f', u'name': u'wait_for_provision_state'}}, {u'__task_execution': {u'id': u'bc2be6f5-b202-467d-85d7-7937255335d9', u'name': u'wait_for_provision_state'}}, {u'__task_execution': {u'id': u'c5e84d18-eab2-4495-ba28-59f9c22c5ba4', u'name': u'wait_for_provision_state'}}, {u'__task_execution': {u'id': u'8f53465e-2d71-4eb4-bc7c-5fb625c11e3c', u'name': u'wait_for_provision_state'}}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=bfc88c27-106e-46e7-a170-9f301203e35e] -> Failed to run action [action_ex_id=146b08b5-da79-4b57-9336-0a4c464cbf15, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'e392ab23-772a-4d53-ab17-d7bb85a04de4', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node e392ab23-772a-4d53-ab17-d7bb85a04de4 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=146b08b5-da79-4b57-9336-0a4c464cbf15, idx=0]: Failed to run action [action_ex_id=146b08b5-da79-4b57-9336-0a4c464cbf15, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'e392ab23-772a-4d53-ab17-d7bb85a04de4', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node e392ab23-772a-4d53-ab17-d7bb85a04de4 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=a02fa3fe-0bb8-4607-8acd-e01a9a4dc4e4] -> Failed to run action [action_ex_id=d6a28a83-4c19-45b0-b152-907b03d45947, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'abf3f6b3-4db0-49e8-abcd-f8100620b92e', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node abf3f6b3-4db0-49e8-abcd-f8100620b92e is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=d6a28a83-4c19-45b0-b152-907b03d45947, idx=0]: Failed to run action [action_ex_id=d6a28a83-4c19-45b0-b152-907b03d45947, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'abf3f6b3-4db0-49e8-abcd-f8100620b92e', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node abf3f6b3-4db0-49e8-abcd-f8100620b92e is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=81f9f2b4-91f6-49da-b825-cb26a13b81b6] -> Failed to run action [action_ex_id=196b6c12-cc16-4f6e-9d95-8c5e00476427, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'11921dbe-267d-4810-b603-91eed0c5ecba', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 11921dbe-267d-4810-b603-91eed0c5ecba is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=196b6c12-cc16-4f6e-9d95-8c5e00476427, idx=0]: Failed to run action [action_ex_id=196b6c12-cc16-4f6e-9d95-8c5e00476427, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'11921dbe-267d-4810-b603-91eed0c5ecba', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 11921dbe-267d-4810-b603-91eed0c5ecba is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=07d2afef-3aea-4476-90df-e70ffcf1e466] -> Failed to run action [action_ex_id=2720cd16-8f77-4e6d-a465-7af662e75f0f, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'6f84e1ea-12f2-407d-9369-922687fd9b6a', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 6f84e1ea-12f2-407d-9369-922687fd9b6a is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=2720cd16-8f77-4e6d-a465-7af662e75f0f, idx=0]: Failed to run action [action_ex_id=2720cd16-8f77-4e6d-a465-7af662e75f0f, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'6f84e1ea-12f2-407d-9369-922687fd9b6a', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 6f84e1ea-12f2-407d-9369-922687fd9b6a is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=331cdb96-c96c-4daa-b110-7dcd0b4a1953] -> Failed to run action [action_ex_id=c9b61246-fa5e-4b4a-b96d-53dcfccb8115, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'df75748c-9036-4ba2-80cb-1db0fb8a5484', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node df75748c-9036-4ba2-80cb-1db0fb8a5484 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=c9b61246-fa5e-4b4a-b96d-53dcfccb8115, idx=0]: Failed to run action [action_ex_id=c9b61246-fa5e-4b4a-b96d-53dcfccb8115, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'df75748c-9036-4ba2-80cb-1db0fb8a5484', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node df75748c-9036-4ba2-80cb-1db0fb8a5484 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=12794227-534d-4d66-8177-0cdfb9aed4f4] -> Failed to run action [action_ex_id=173db264-22c6-4df3-ab4a-1e9df30637b9, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'07c42c39-23b1-4cee-8ec4-ca3a3f131012', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 07c42c39-23b1-4cee-8ec4-ca3a3f131012 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=173db264-22c6-4df3-ab4a-1e9df30637b9, idx=0]: Failed to run action [action_ex_id=173db264-22c6-4df3-ab4a-1e9df30637b9, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'07c42c39-23b1-4cee-8ec4-ca3a3f131012', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 07c42c39-23b1-4cee-8ec4-ca3a3f131012 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=1aa19bce-4666-4c66-b27b-83b88fcd256c] -> Failed to run action [action_ex_id=afeddb1e-87b1-4b27-8a11-c101ab4008ab, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'856071f4-b14c-4edf-9282-9e152148df51', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 856071f4-b14c-4edf-9282-9e152148df51 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=afeddb1e-87b1-4b27-8a11-c101ab4008ab, idx=0]: Failed to run action [action_ex_id=afeddb1e-87b1-4b27-8a11-c101ab4008ab, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'856071f4-b14c-4edf-9282-9e152148df51', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 856071f4-b14c-4edf-9282-9e152148df51 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=0661c6bb-fe14-4e8a-a4e0-88091b87af07] -> Failed to run action [action_ex_id=daf1d85a-0285-436b-b7fa-7088abd2b62c, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'33d10b6c-6740-44e7-b6fb-ffe37c1cca36', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 33d10b6c-6740-44e7-b6fb-ffe37c1cca36 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=daf1d85a-0285-436b-b7fa-7088abd2b62c, idx=0]: Failed to run action [action_ex_id=daf1d85a-0285-436b-b7fa-7088abd2b62c, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'33d10b6c-6740-44e7-b6fb-ffe37c1cca36', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 33d10b6c-6740-44e7-b6fb-ffe37c1cca36 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=acc18a31-8a33-4c27-9101-49c84a840898] -> Failed to run action [action_ex_id=3e241118-d5a2-497a-9426-131a732d6926, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'9237c20c-e38a-4f74-a944-377f74d166a9', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 9237c20c-e38a-4f74-a944-377f74d166a9 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=3e241118-d5a2-497a-9426-131a732d6926, idx=0]: Failed to run action [action_ex_id=3e241118-d5a2-497a-9426-131a732d6926, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'9237c20c-e38a-4f74-a944-377f74d166a9', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 9237c20c-e38a-4f74-a944-377f74d166a9 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}, {u'result': u"Failure caused by error in tasks: set_provision_state

  set_provision_state [task_ex_id=6364c269-13f9-436e-9eaa-96d9d4d88b2e] -> Failed to run action [action_ex_id=3729c810-a7f8-435c-88e9-a9f6131f1af8, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'897738ce-6cab-43eb-a37d-31214f4e8783', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 897738ce-6cab-43eb-a37d-31214f4e8783 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
    [action_ex_id=3729c810-a7f8-435c-88e9-a9f6131f1af8, idx=0]: Failed to run action [action_ex_id=3729c810-a7f8-435c-88e9-a9f6131f1af8, action_cls='<class 'mistral.actions.action_factory.IronicAction'>', attributes='{u'client_method_name': u'node.set_provision_state'}', params='{u'state': u'manage', u'node_uuid': u'897738ce-6cab-43eb-a37d-31214f4e8783', u'configdrive': None, u'cleansteps': None}']
 IronicAction.node.set_provision_state failed: <class 'ironicclient.common.apiclient.exceptions.Conflict'>: Node 897738ce-6cab-43eb-a37d-31214f4e8783 is locked by host undercloud-0.redhat.local, please retry after the current operation is completed.
"}]

Expected results:
Import finishes ok. 

Additional info:
The hypervisor host has enough resources to accomodate the VMs: 4 physical Xeon E7-8857 v2 with 1TB of RAM. The undercloud has assigned 4 vCPUs with 16G of RAM.