Execution error when running with the same workflow in parallel

[Lingxian Kong]

my workflow:

---
version: '2.0'

create_vm:
  type: direct
  input:
    - vm_name
    - image_ref
    - flavor_ref
  output:
    vm_id: <% $.vm_id %>

  tasks:
    create_server:
      action: nova.servers_create name=<% $.vm_name %> image=<% $.image_ref %> flavor=<% $.flavor_ref %>
      publish:
        vm_id: <% $.create_server.id %>
      on-success:
        - check_server_exists

    check_server_exists:
      action: nova.servers_get server=<% $.vm_id %>
      publish:
        server_exists: True
      on-success:
        - wait_instance

    wait_instance:
      action: nova.servers_find id=<% $.vm_id %> status='ACTIVE'
      retry:
        delay: 5
        count: 15

create 2 executions with the workflow, run in parallel, 1 of the 2 executions will be ERROR, the trace log:

2015-04-25 05:51:36.990 14491 DEBUG mistral.actions.openstack.base [-] method:<bound method ServerManager.get of <novaclient.v2.servers.ServerManager object at 0x6673910>>, params:{u'image': u'cfba9e7f-5dbd-4efb-bd1b-6c9d7093f540', u'name': u'test', u'flavor': u'1'}, method run /usr/local/lib/python2.7/dist-packages/mistral/actions/openstack/base.py:74
2015-04-25 05:51:36.992 14491 ERROR mistral.engine.default_executor [-] Failed to run action [action_execution_id=f4bc2720-f653-4c94-8483-5362bfba49b6, action_cls='<class 'mistral.actions.openstack.actions.NovaAction'>', attributes='{u'client_method_name': u'servers.create'}' params='{u'image': u'cfba9e7f-5dbd-4efb-bd1b-6c9d7093f540', u'name': u'test', u'flavor': u'1'}']
 NovaAction.servers.get failed: <type 'exceptions.TypeError'>: get() got an unexpected keyword argument 'image'
2015-04-25 05:51:36.992 14491 TRACE mistral.engine.default_executor Traceback (most recent call last):
2015-04-25 05:51:36.992 14491 TRACE mistral.engine.default_executor File "/usr/local/lib/python2.7/dist-packages/mistral/engine/default_executor.py", line 53, in run_action
2015-04-25 05:51:36.992 14491 TRACE mistral.engine.default_executor result = action.run()
2015-04-25 05:51:36.992 14491 TRACE mistral.engine.default_executor File "/usr/local/lib/python2.7/dist-packages/mistral/actions/openstack/base.py", line 82, in run
2015-04-25 05:51:36.992 14491 TRACE mistral.engine.default_executor (self.__class__.__name__, self.client_method_name, e_str)
2015-04-25 05:51:36.992 14491 TRACE mistral.engine.default_executor ActionException: NovaAction.servers.get failed: <type 'exceptions.TypeError'>: get() got an unexpected keyword argument 'image'
2015-04-25 05:51:36.992 14491 TRACE mistral.engine.default_executor

or

2015-04-25 05:34:38.163 14175 ERROR mistral.engine.default_executor [-] Failed to run action [action_execution_id=43690fa4-3911-43bc-9dc6-9bdeb5565162, action_cls='<class 'mistral.actions.openstack.actions.NovaAction'>', attributes='{u'client_method_name': u'servers.get'}' params='{u'server': u'a9aab6ad-989f-41ad-bed5-ac143aa4e7df'}']
 NovaAction.servers.create failed: <type 'exceptions.TypeError'>: create() takes at least 4 arguments (1 given)
2015-04-25 05:34:38.163 14175 TRACE mistral.engine.default_executor Traceback (most recent call last):
2015-04-25 05:34:38.163 14175 TRACE mistral.engine.default_executor File "/usr/local/lib/python2.7/dist-packages/mistral/engine/default_executor.py", line 53, in run_action
2015-04-25 05:34:38.163 14175 TRACE mistral.engine.default_executor result = action.run()
2015-04-25 05:34:38.163 14175 TRACE mistral.engine.default_executor File "/usr/local/lib/python2.7/dist-packages/mistral/actions/openstack/base.py", line 78, in run
2015-04-25 05:34:38.163 14175 TRACE mistral.engine.default_executor (self.__class__.__name__, self.client_method_name, e_str)
2015-04-25 05:34:38.163 14175 TRACE mistral.engine.default_executor ActionException: NovaAction.servers.create failed: <type 'exceptions.TypeError'>: create() takes at least 4 arguments (1 given)
2015-04-25 05:34:38.163 14175 TRACE mistral.engine.default_executor

root cause:
client_method_name is OpenStackAction class variable, it will be overrided by other executors during action class construction.

def construct_action_class(action_class_str, attributes):
    # Rebuild action class and restore attributes.
    action_class = importutils.import_class(action_class_str)

    for name, value in attributes.items():
        setattr(action_class, name, value) # here is the magic

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/177739

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/177739
Committed: https://git.openstack.org/cgit/stackforge/mistral/commit/?id=f8d2d5c164fd193c8d97cd35c046f512a070352b
Submitter: Jenkins
Branch: master

commit f8d2d5c164fd193c8d97cd35c046f512a070352b
Author: Nikolay Mahotkin <email address hidden>
Date: Mon Apr 27 15:18:06 2015 +0300

    Fix bug with action class attributes

     * Need to write an integration test for it.

    Closes-Bug: #1448403

    Change-Id: I7f477f6c87b21ff0f8c9a31ae72086830c7fa9b4

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/kilo
Review: https://review.openstack.org/178634

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/178634
Committed: https://git.openstack.org/cgit/stackforge/mistral/commit/?id=16eeb9f09921767eb5ed24ca325dfd5a74344792
Submitter: Jenkins
Branch: stable/kilo

commit 16eeb9f09921767eb5ed24ca325dfd5a74344792
Author: Nikolay Mahotkin <email address hidden>
Date: Mon Apr 27 15:18:06 2015 +0300

    Fix bug with action class attributes

     * Need to write an integration test for it.

    Closes-Bug: #1448403

    Change-Id: I7f477f6c87b21ff0f8c9a31ae72086830c7fa9b4
    (cherry picked from commit f8d2d5c164fd193c8d97cd35c046f512a070352b)