WF execution is not created if input preparation of initial task fails

[Moshe Elisha]

If an issue occurs on a stage where we're preparing task input data, for example, a workflow execution will not be created and the execution-create response will be different.
The first task(s) execution objects get created simultaneously with WF execution, within the same transaction
if something is wrong with preparing at least with one of those objects then entire TX rolls back

In case of a WF with two starting tasks in parallel and one is OK and the other throws an error on input preparation the whole WF execution object won't be created.
A successful start task should be saved in DB for sure (as well as WF execution), otherwise we loose all tracking information

This can be reproduced with the following WF:

---
version: '2.0'

fail_on_initial:
  type: direct
  tasks:
    iniitial_task:
      action: std.echo output=<% $.non_existing_yaql_method() %>

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/239638

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/239638
Committed: https://git.openstack.org/cgit/openstack/mistral/commit/?id=e0c00aa51634d84bed5a3bdbe07339bafc56979f
Submitter: Jenkins
Branch: master

commit e0c00aa51634d84bed5a3bdbe07339bafc56979f
Author: Nikolay Mahotkin <email address hidden>
Date: Tue Oct 27 13:23:25 2015 +0300

    Fixing wf execution creation at initial stage

     * Wf execution is not created when first
       task(s) failed.
     * Fixed some unit-tests.

    Closes-Bug: #1506470

    Change-Id: Id34b11efe15fcff0a9360e2966d1a85c29325c62

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/liberty
Review: https://review.openstack.org/246838

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/246838
Committed: https://git.openstack.org/cgit/openstack/mistral/commit/?id=b8e1f95acd26c5043a164d17889e731692bbf7b1
Submitter: Jenkins
Branch: stable/liberty

commit b8e1f95acd26c5043a164d17889e731692bbf7b1
Author: Nikolay Mahotkin <email address hidden>
Date: Tue Oct 27 13:23:25 2015 +0300

    Fixing wf execution creation at initial stage

     * Wf execution is not created when first
       task(s) failed.
     * Fixed some unit-tests.

    Closes-Bug: #1506470

    Change-Id: Id34b11efe15fcff0a9360e2966d1a85c29325c62
    (cherry picked from commit e0c00aa51634d84bed5a3bdbe07339bafc56979f)

[Thierry Carrez (ttx)]

This issue was fixed in the openstack/mistral 2.0.0.0b1 development milestone.

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/mistral 1.0.1 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/mistral 1.0.1 release.